DEGA - Deutsche Gesellschaft für Akustik e.V. - Programme ...CFA/DAGA’04 - Programme booklet...

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CFA/DAGA’04 - Programme booklet

Imprint:

DEGA GeschäftsstelleDidier Cassereau, Christian Nockec/o Universität OldenburgPhysik - AkustikD-26111 OldenburgTel.: 0441 798-3561Fax: 0441 798-3698e-mail: [email protected]: http://www.dega-akustik.de

Telephone during the conference:+33 (0) 388 24 29 49+33 (0) 388 24 29 50

Fax during the conference:+33 (0) 388 24 29 51

e-mail: [email protected]

ProgrammeProgrammheft

Congrès Joint / Gemeinschaftstagung

7ème Congrès Français d’Acoustique CFA30. Deutsche Jahrestagung für Akustik DAGA

Strasbourg, France

Straßburg, Frankreich

22 – 25 mars 2004

22. bis 25. März 2004

7ème Congrès Français d’Acoustique CFA30. Deutsche Jahrestagung für Akustik DAGA

with support by the Swiss Acoustical Society SFA–SGAin co-operation with:• ITG "Informationstechnische Gesellschaft im VDE" (Informa-

tion Technology Section, ITG, within the German Associationfor Electrical, Electronic & Information Technologies, VDE),

• NALS "Normenausschuss Akustik, Lärmminderung undSchwingungestechnik" (German Standards CommitteeAcoustics, Noise Reduction and Vibration) of DIN and VDI

• DPG "Deutsche Physikalische Gesellschaft" (German Physi-cal Society)

Imprint:

DEGA GeschäftsstelleChristian Nocke, Didier Cassereauc/o Universität OldenburgPhysik - AkustikD-26111 OldenburgTel.: +49 (0) 441 798-3561Fax: +49 (0) 441 798-3698e-mail: [email protected]: http://www.dega-akustik.de

Telephone during the conference:+33 (0) 3 88 24 29 49+33 (0) 3 88 24 29 50

Fax during the conference:+33 (0) 388 24 29 51

e-mail: [email protected]

Print: Isensee Verlag, Oldenburg

Type setting: LATEX 2ε

Program CFA/DAGA’04 1

Contents

CFA/DAGA‘04 – General information

Time schedules . . . . . . . . . . . . . . . . . . . . . . . . 4

Le mot de bienvenue des présidents du congrès . . . . . . 17Grußwort der Tagungsleitung . . . . . . . . . . . . . . . . . 19Welcome address . . . . . . . . . . . . . . . . . . . . . . . 21

Informations générales . . . . . . . . . . . . . . . . . . . . 23Hinweise zur Tagung . . . . . . . . . . . . . . . . . . . . . . 31General information . . . . . . . . . . . . . . . . . . . . . . 39

Course of meetingOpening of CFA/DAGA’04 . . . . . . . . . . . . . . . . . . . 47

Plenary lectures . . . . . . . . . . . . . . . . . . . . . . . . 47

Paper Sessions MondayCar acoustics I . . . . . . . . . . . . . . . . . . . . . . . . . 49Room acoustics: simulation, measuring techniques and au-

ralisation I . . . . . . . . . . . . . . . . . . . . . . . . . . 55Recent advances in speech quality modelling . . . . . . . . 62Active control I . . . . . . . . . . . . . . . . . . . . . . . . . 67Musical acoustics . . . . . . . . . . . . . . . . . . . . . . . 74Thermo- and flowacoustics . . . . . . . . . . . . . . . . . . 81Physical acoustics I . . . . . . . . . . . . . . . . . . . . . . 89Measuring methods in building acoustics I . . . . . . . . . . 96Global reduction of transportation noise . . . . . . . . . . . 104Localization of normal hearing and hearing impaired persons111Microphones and loudspeakers . . . . . . . . . . . . . . . . 116

Paper Sessions TuesdayCar acoustics II . . . . . . . . . . . . . . . . . . . . . . . . . 119Car acoustics III . . . . . . . . . . . . . . . . . . . . . . . . 122Room acoustics : simulation, measuring techniques and

auralisation II . . . . . . . . . . . . . . . . . . . . . . . . 128Concert hall acoustics . . . . . . . . . . . . . . . . . . . . . 132Environmental noise and machinery noise I . . . . . . . . . 136Temporal aspects in the perception of sound and speech

quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137Outdoor sound localization . . . . . . . . . . . . . . . . . . 144Active control II . . . . . . . . . . . . . . . . . . . . . . . . . 147Non linear acoustics . . . . . . . . . . . . . . . . . . . . . . 153Numerical methods in acoustics I . . . . . . . . . . . . . . . 158Hydroacoustics, underwater acoustics . . . . . . . . . . . . 169

2 CFA/DAGA’04 Program

Noise from leisure activities . . . . . . . . . . . . . . . . . . 175Soundscapes and community noise . . . . . . . . . . . . . 177Measuring methods in building acoustics II . . . . . . . . . 189Rating methods in building acoustics . . . . . . . . . . . . . 190Building acoustics I . . . . . . . . . . . . . . . . . . . . . . 193Temporal envelope processing in hearing . . . . . . . . . . 198Change detection and repetition detection in hearing . . . . 207Silicon and other microphones . . . . . . . . . . . . . . . . 210Speech in vehicles . . . . . . . . . . . . . . . . . . . . . . . 217

Paper Sessions WednesdayCar acoustics IV . . . . . . . . . . . . . . . . . . . . . . . . 220Benchmarking tests in automobile industy . . . . . . . . . . 228Physical acoustics II . . . . . . . . . . . . . . . . . . . . . . 230Outdoor sound propagation I . . . . . . . . . . . . . . . . . 240Physical acoustics - cavitation and sonoluminescence . . . 245Auralisation . . . . . . . . . . . . . . . . . . . . . . . . . . . 251Railway Noise II . . . . . . . . . . . . . . . . . . . . . . . . 256Railway noise . . . . . . . . . . . . . . . . . . . . . . . . . . 262Sound reinforcement and immission control . . . . . . . . . 267Numerical methods in acoustics II . . . . . . . . . . . . . . 273Audiology . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277Medical acoustics I . . . . . . . . . . . . . . . . . . . . . . . 281Ultrasonic non-destructive testing . . . . . . . . . . . . . . . 285Building acoustics II . . . . . . . . . . . . . . . . . . . . . . 295Flow noise . . . . . . . . . . . . . . . . . . . . . . . . . . . 297Application of psychoacoustics I . . . . . . . . . . . . . . . 307Environmental noise and machinery noise II . . . . . . . . . 319Wave field synthesis I . . . . . . . . . . . . . . . . . . . . . 327

Paper Sessions ThursdaySilencers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328Audiovisual interaction . . . . . . . . . . . . . . . . . . . . . 332Ultrasonic transducers I . . . . . . . . . . . . . . . . . . . . 335Organ and room . . . . . . . . . . . . . . . . . . . . . . . . 340Outdoor sound propagation II . . . . . . . . . . . . . . . . . 344Ultrasonic transducers II . . . . . . . . . . . . . . . . . . . . 348Medical acoustics II . . . . . . . . . . . . . . . . . . . . . . 350Speech and voice - analysis and synthesis . . . . . . . . . 352Wave field synthesis II . . . . . . . . . . . . . . . . . . . . . 356Assessment of noise exposure in the frame of the environ-

mental noise directive . . . . . . . . . . . . . . . . . . . 360Sonic boom . . . . . . . . . . . . . . . . . . . . . . . . . . . 364Psychoacoustical methods in musical acoustics . . . . . . . 373


Sleep, noise and health . . . . . . . . . . . . . . . . . . . . 376Vibration from railway lines . . . . . . . . . . . . . . . . . . 380Application of psychoacoustics II . . . . . . . . . . . . . . . 385Combined noise evaluation . . . . . . . . . . . . . . . . . . 394

Poster sessionsPoster Tuesday . . . . . . . . . . . . . . . . . . . . . . . . . 399Poster Wednesday . . . . . . . . . . . . . . . . . . . . . . . 412Poster Thursday . . . . . . . . . . . . . . . . . . . . . . . . 428

How to reach Strasbourg . . . . . . . . . . . . . . . . . . 468

Maps of Strasbourg . . . . . . . . . . . . . . . . . . . . . 468

Maps of congress centre . . . . . . . . . . . . . . . . . . 471

Index of authors . . . . . . . . . . . . . . . . . . . . . . . . 473

Registration form . . . . . . . . . . . . . . . . . . . . . . 487


Le mot de bienvenue des présidents du congrès

Chères collègues, chers collègues,Après avoir vécu pendant 50 ans dans la construction de nom-breuses actions et activités communes, c’est aujourd’hui vrai-ment une première que le rapprochement de nos deux commu-nautés de l’acoustique française et allemande à l’occasion de cecongrès préparé, organisé et vécu ensemble, le CFA/DAGA’04.Les deux pays qui ont déjà réalisé dans le passé des congrèscommuns avec leurs voisins, souvent parlant la même langue,donnent ici un exemple de bons voisins « s’entendant » par-dessus les barrières linguistiques en organisant ensemble lecongrès CFA/DAGA’04 qui est la réunion du « 7ème Congrès Fran-çais d’Acoustique (CFA) » et du « 30. Deutsche Jahrestagung fürAkustik (DAGA) ».Il fut évident, même obligatoire, qu’un tel événement dût avoirlieu dans la ville qui représente comme aucune autre nos va-leurs communes et ce qui nous lie, les Allemands et les Fran-çais, et c’est bien sûr Strasbourg, même si l’on doit y aban-donner quelques habitudes, comme par exemple les frais decongrès traditionnellement très bas en Allemagne. Seule la villede Strasbourg avec son histoire commune franco-allemande etaujourd’hui son rang de métropole européenne peut conférer àce congrès l’attrait qu’il mérite.Il était également naturel d’intégrer la Suisse pour contribuer àcette réunion franco-allemande, puisque c’est un pays où lesdeux langues allemande et française se côtoient dans les dis-cours sur l’acoustique.D’ores et déjà, lors de l’achèvement de ce livret des résumés, lebut est atteint : 697 résumés, dont 384 de l’Allemagne et 197 dela France, 28 de la Suisse, 70 venant de 13 autres pays del’Europe de l’Est et de l’Ouest ainsi que 18 conférences de 7pays non-européens. Ces chiffres montrent qu’on a dépassé lasomme des résumés habituels des deux congrès nationaux : uneréunion dont l’attrait dépasse de beaucoup le cadre des acous-ticiens allemands et français qui nous invitent à les rencontrer.Le spectre professionnel couvert par le congrès est très large etreflète très bien la grande importance de l’acoustique d’aujour-d’hui.Qu’il s’agisse de la recherche plus fondamentale ou de l’in-novation dans des domaines techniques, de la communicationacoustique, comme par exemple la transmission du langage oude la musique, de la conception optimale de salles de confé-rences, de l’amélioration de la qualité acoustique de notre envi-ronnement ou bien qu’il s’agisse de produits construits et utiliséspour nos besoins, dont les propriétés acoustiques sont perçues


de plus en plus consciemment, et qui seront conçus conformé-ment à ces perceptions : l’acoustique, discipline physique clas-sique, s’est encore développée ces dernières années pour de-venir encore plus un sujet interdisciplinaire et novateur fonda-mental dans beaucoup de domaines d’applications physiques ettechniques. Les nombreuses conférences du CFA/DAGA’04 fontaussi preuve de ce développement.Vu le grand nombre de conférences, nous avons dû faire dessacrifices, comme par exemple les pré-colloques traditionnels aulieu desquels le congrès lui-même se tiendra lundi après-midi. Demême une autre habitude importante – l’utilisation de la languenationale, ou l’allemand ou le français – sera abandonnée enfaveur de l’anglais qui est plus courant pour la plupart des au-diteurs. Cependant nous sommes convaincus que de tels sacri-fices sont vraiment justifiés par l’union des traditions de congrèsallemandes et françaises car cette union représente une plate-forme idéale pour connaître mieux l’acoustique, les acousticienset leur travail dans les pays germanophones et francophones.Profitez de cette occasion, laissez-vous séduire par un congrèsqui met en scène un échange de pensées et d’informationsentre les acousticiens parlant allemand et français, laissez vosoreilles entendre – tout en respectant la différence linguistique– la langue que nous avons tous en commun, à savoir l’acous-tique, permettez qu’elle devienne notre langue maternelle com-mune pour trois journées et demi.Dans ce but, l’équipe responsable de l’organisation et du pro-gramme a essayé de travailler de manière optimale en collabo-ration étroite avec les sociétés nationales, la Société Françaised’Acoustique, SFA, et la société allemande, la Deutsche Gesell-schaft für Akustik, DEGA. Cette tâche n’a pas toujours été facileà cause des distances qui séparaient les membres de l’équiped’organisation. Pourtant, ce travail a été possible non seulementgrâce aux moyens de communication électroniques modernesmais aussi, dans la même mesure au moins, grâce au grand en-gagement de tous ceux qui ont participé aux différentes étapesde cette organisation.Nous aimerions d’ores et déjà exprimer à toute cette équipe nosremerciements les plus cordiaux. Ensemble avec cette équipeorganisatrice, nous souhaitons à tous et surtout à vous, visiteursdu CFA/DAGA’04, que ce congrès s’avère satisfaisant et stimu-lant et qu’il offre à tous les participants un séjour agréable, remplide connaissances et d’informations dans cette merveilleuse villeinfluencée par la France et l’Allemagne : la ville de Strasbourg.

Pour le comité d’organisation français/allemand :

Jacques Châtillon Joachim ScheurenPrésident du congrès Président du congrès


Grußwort der Tagungsleiter

Liebe Kolleginnen und Kollegen,es ist ein echtes Novum, dass Franzosen und Deutsche, diein den letzten 50 Jahren aus ihrer räumlichen und historischenNähe zahllose gemeinsame Aktionen und Aktivitäten abgelei-tet haben, nun auch „akustisch“ zueinander finden: in einer ge-meinsam vorbereiteten, veranstalteten und erlebten Tagung, derCFA/DAGA’04. Nachdem beide Länder in der Vergangenheitschon gemeinsame Tagungen mit ihren überwiegend gleichspra-chigen Nachbarn veranstaltet haben, setzen sie nun mit demals CFA/DAGA’04 gemeinschaftlich veranstalteten „7ème CongrèsFrançais d’Acoustique (CFA)“ und der „30. Deutschen Jahres-tagung für Akustik (DAGA)“ über die Sprachbarriere hinweg einZeichen für eine gute „akustische“ Nachbarschaft.Es war naheliegend, ja zwingend, ein solches Ereignis in derStadt, die wie keine andere für das Gemeinsame und Verbin-dende von Deutschen und Franzosen steht, stattfinden zu las-sen: in Straßburg im Herzen des Elsass. Auch wenn dadurcheinige Gewohnheiten einschließlich der in Deutschland traditio-nell sehr niedrigen Tagungsgebühr aufgegeben werden mussten:Nur Straßburg mit seiner wechselvoll bewegten Vergangenheit imdeutsch/französischen Grenzgebiet verleiht dieser Tagung denihr zukommenden Reiz, nur Straßburg hat diese Tagung verdient.Naheliegend war es auch, die Schweiz, in der Deutsch und Fran-zösisch auch in der Akustik eine bedeutende Rolle spielen, un-terstützend in eine deutsch/französische Tagung zu integrieren.Schon jetzt, bei Fertigstellung dieses Programmhefts, kann dasErgebnis sich sehen lassen: 697 Vorträge, davon 384 ausDeutschland und 197 aus Frankreich, 28 aus der Schweiz,70 aus 13 weiteren ost- und westeuropäischen Ländern sowie18 Vorträge aus 7 nichteuropäischen Übersee-Ländern zeigen,dass mehr als die Summe zweier nationaler Tagungen erreichtwurde: ein Treffen, dessen Anziehungskraft weit über die einla-denden deutschen und französischen Akustiker hinaus wirksamist. Das dabei eröffnete fachliche Spektrum ist riesig und bildetdie große Breite der heutigen Akustik trefflich ab.Denn ganz gleich ob bei der Erforschung neuer akustischer Ef-fekte in Physik, Technik und Biologie, bei der akustischen Kom-munikation, etwa der adäquaten Übermittlung von Sprache oderMusik, bei der optimalen Gestaltung von Hörräumen, bei der Ver-besserung der durch wachsenden Lärm gefährdeten akustischenQualität unserer Umwelt oder bei den immer bewusster registrier-ten und deshalb auch gestalteten akustischen Eigenschaften dervon uns erstellten und benutzten Produkte: die klassische phy-sikalische Disziplin Akustik hat sich gerade in den letzten Jah-ren zu einer wichtigen interdisziplinären und innovativen Disziplinin vielen physikalischen und technischen Anwendungsbereichen


entwickeln können. Auch davon zeugen die zahlreichen Vorträgeder CFA/DAGA’04.Der Vortragsfülle mussten Opfer gebracht werden, etwa die tra-ditionellen Vorkolloquien der DAGA, an deren Stelle nun die Ta-gung selbst den Montagnachmittag in Anspruch nimmt. Auch ei-ne andere bedeutende Gewohnheit, die Verwendung der deut-schen oder französischen Landessprache, wird in den meistenFällen der einem größeren Hörerkreis zugänglichen englischenSprache den Vortritt lassen. Wir sind aber überzeugt, dass sol-che Opfer sich durch die Verbindung deutscher und französischerTagungstradition mehr als rechtfertigen. Denn diese bietet eineideale, einzigartige Plattform, die Akustik, die Akustiker und de-ren Arbeit in den deutschund französischsprachigen Ländernnäher kennen zu lernen.Nutzen Sie diese Gelegenheit, lassen Sie sich ein auf diese Ta-gung, auf den mit ihr inszenierten Gedanken- und Informations-austausch zwischen Deutsch und Französisch sprechenden Aku-stikern, lassen Sie sich – bei aller sprachlichen Verschiedenheit -von der uns allen gemeinsamen Sprache, der Akustik, anstecken,lassen Sie diese für dreieinhalbe Tage unsere gemeinsame Mut-tersprache werden.Das Vorbereitungs- und Programmteam hat versucht, dafür inenger Absprache mit den tragenden akustischen Gesellschaf-ten, der Société Française d’Acoustique, SFA, und der Deut-schen Gesellschaft für Akustik, DEGA, die bestmöglichen Vor-aussetzungen zu schaffen. Wegen der weiträumigen Verstreut-heit fast aller Beteiligten war dies nicht immer einfach. Dass esdennoch möglich war, liegt nicht nur an den modernen elektroni-schen Kommunikationsmitteln sondern mindestens in gleichemMaß an dem großen Engagement all derer, die diese Mittel fürdie notwendige und mitunter mühsame Kommunikation und Ab-stimmung zu nutzen wussten.Ihnen allen möchten wir schon hier unseren herzlichen Dankaussprechen. Und mit ihnen gemeinsam wünschen wir uns undIhnen, den Besuchern der CFA/DAGA’04, dass diese Tagungeinen guten und anregenden Verlauf nimmt und allen Teilneh-mern eine angenehme, erkenntnis- und informationsreiche Zeitin der wunderbaren, französisch/deutsch geprägten Stadt Straß-burg beschert.

Für das deutsch/französische Vorbereitungskomitee:

Joachim Scheuren Jacques ChâtillonTagungsleiter Tagungsleiter


Welcome address of the conference chairs

Dear colleagues,It’s a real novelty that French and Germans, whose proximity andhistorical vicinity have brought them an endless number of com-mon actions and activities within the last 50 years, now also meet“acoustically”: at a jointly prepared, organised and experiencedcongress, the CFA/DAGA’04. Since both countries in the past al-ready organised congresses with those neighbours, who mainlyspeak the same language, they now point the way to the futurefor a good “acoustical” neighbourhood ignoring the language bar-rier by jointly running the “7ème Congrès Français d’Acoustique(CFA)“ and the „30. Deutsche Jahrestagung für Akustik (DAGA)“together as CFA/DAGA’04.It was obvious and even compelling that such an event takesplace in a city, which like no other city represents the associa-tion and connection of Germans and French: Strasbourg in theheart of Alsace. Although this meant that some habits had tobe given up, including the traditionally very low congress fees inGermany, only Strasbourg with its eventful and exciting past atthe French-German border area gives this congress its appropri-ate attraction, only Strasbourg deserves this congress.It was obvious again that Switzerland, where German and Frenchare important languages in acoustics too, also supports and par-ticipates in this joint French-German congress.And now already, when finishing the program booklet, an impres-sive result can be stated: 697 presentations, thereof 384 fromGermany and 197 from France, 28 from Switzerland, 70 presen-tations from 13 Eastern and Western European countries as wellas 18 presentations from 7 Non-European overseas countries.This shows that more than just the sum of two national con-gresses has been achieved: a meeting, which is equally attractivefor other nations beyond the inviting German and French acous-ticians. The technical spectrum emerging from this is enormousand outstandingly reflects the wide range of today’s acoustics.No matter whether we consider the investigation of new acousticeffects in physics, technology and biology, the acoustic commu-nication like adequate transmission of speech or music, the op-timal design of listening rooms, the improvement of the acousti-cal quality of our environment being threatened by growing noiseor the more and more noticed and therefore designed acous-tic properties of products manufactured and used by us: espe-cially in recent years the classic physical field of acoustics hasdeveloped into an important interdisciplinary and innovative dis-cipline in many physical and technical fields of application. Againthis is proven and illustrated by the numerous presentations atCFA/DAGA’04.


Because of the great number of presentations sacrifices had tobe made like the traditional colloquia of DAGA typically preced-ing the actual congress. They had to be replaced this time by thecongress itself on Monday afternoon. And then, another signifi-cant habit, the use of the German or French national language,will give precedence to the English language in most cases asthis will be understood by a greater audience. Nevertheless, weare convinced that such sacrifices are more than justified by link-ing German and French congress traditions. Such a congressoffers an ideal, unique platform to mutually improve the acquain-tance with acoustics, acousticians and their work in German andFrench-speaking countries.Take this opportunity, get involved in this congress, in its ex-change of thoughts and information between German- andFrench-speaking acousticians and - besides all differences in lan-guage - get infected by the language we all have in common,by acoustics, and let become this our native language for thesethree and a half days.To enable this, the organising and program team tried to establishoptimum conditions in close cooperation with the main acous-tic societies, the Société Française d’Acoustique, SFA and theDeutsche Gesellschaft für Akustik, DEGA. As nearly all contrib-utors were widely scattered, this was not always easy. But nev-ertheless it was possible, and this is not only due to the mod-ern electronic means of communication but even more to thestrong commitment of all those people who were able to usethese means for the necessary and sometimes difficult commu-nication and coordination.At this point we would like to take the opportunity to thank themall. And, together with them, we would like to wish everyone,all visitors of the CFA/DAGA’04, that this congress runs well andstimulates all participants by a pleasant and informative time inthe wonderful city of Strasbourg.

For the German-French organising committee:

Joachim Scheuren Jacques Châtillonconference chair conference chair


Informations générales

CFA/DAGA‘0430. Deutsche Jahrestagung für Akustik

7ème Congrès Français d’AcoustiqueLe 7ème Congrès de la Société Française d’Acoustique (CFA) estorganisé conjointement avec le 30ème Congrès de la Société Al-lemande d’Acoustique (DAGA) du 22 au 25 mars 2004 à Stras-bourg (France) au Palais des Congrès. Cet évènement a le sou-tien de la Société Suisse d’Acoustique.

Rendez-vousSa situation géographique centrale et son histoire agitée entrel’Allemagne et la France font de Strasbourg un centre européenet un symbole du voisinage et de la coopération entre nations.Strasbourg est l’une des rares villes au monde dont le centre aété déclaré héritage mondial.Le palais des congrès est situé à environ 10 minutes à pieddu centre historique. Les auditoriums très bien équipés, ainsiqu’un grand hall d’exposition, constituent les conditions idéalespour un congrès réussi pour toutes les personnes intéresséespar l’acoustique, qu’elles viennent d’Allemagne, de France, deSuisse ou de tout autre pays d’Europe ou hors Europe.Adresse :Palais de la musique et du CongrèsPlace de Bordeaux – Wacken –F–67082 Strasbourg CedexDe plus amples informations sont disponibles à l’adresse sui-vante :http ://www.strasbourgmeeting.com

OrganisationLe congrès est organisé conjointement par les Sociétés Fran-çaise et Allemande d’Acoustique, la SFA et la DEGA, avec lesoutien de la Société Suisse d’Acousique, la SGA–SSA, en col-laboration avec l’« ITG – Informationstechnische Gesellschaft imVDE »(section technologies d’information de l’association alle-mande pour les technologies électriques, électronique et d’infor-mation), le « NALS – Normenausschuss Akustik, Lärmminderungund Schwingungestechnik »(Comité de normalisation allemandpour l’acoustique, la luttre contre le brut et les vibrations) du DINet du VDI et la « DPG – Deutsche Physikalische Gesellschaft»(Société Allemande de Physique).

Présidents du congrès et comité d’organisationPrésidents de la conférence

Jacques Châtillon et Joachim Scheuren.

Soutenus par :


Coordination du congrèsDelphine Noël Alfred Schmitz

Inscription et secrétariatEvelyne Dewayse Regina Condin, Christian Nocke

Salon européen d’acoustiqueClaude Legros (coordination)

Patrick Luquet, Cécile Rodet Klaus Genuit, Diana Schreiber

FinancesJacques Châtillon Hugo Fastl

Publication et internetDidier Cassereau Malte Kob

Comité scientifiqueArmand Dancer (organisateurs de session) Michael MöserHenri Arbey Heinz-Martin FischerJean Louis Guyader Armin KohlrauschJean Kergomard Wolfgang Kropp

Beat Hohmann (SGA-SSA)

Organisation localeGuillaume Dutilleux, Catherine Serve Rainer Riedlinger

Coordination techniqueJoachim Feldmann

Langues officiellesL’anglais sera la langue privilégiée pendant la conférence ; ce-pendant les langues française et allemande sont également bien-venues.

Programme du congrésCe congrès franco-allemand CFA/DAGA’04 abordera tous lesthèmes de l’acoustique : acoustique architecturale, acous-tique industrielle, acoustique non-linéaire, acoustique physique,acoustique sous-marine, acousto-optique, aéroacoustique, audi-tion, communication parlée, contrôle actif et passif, contrôle non-destructif, design sonore, diffusion, électroacoustique, environ-nement, hydroacoustique, imagerie, instrumentation, méthodesnumériques, métrologie, propagation, thermoacoustique, traite-ment du signal.

Sessions plénièresLes conférences invitées sont orientées vers des sujets d’intérêtgénéral :– P. Avan, Faculté de Médecine, Clermont-Ferrand, France

"Auditory distortion : toward a non-invasive dissection of co-chlear micromechanics"


– H.-E.Meier, DaimlerChrysler AG, Germany"Vehicle acoustics : chances for application of research re-sults"

– M. Rossi, Ecole Polytechnique Fédérale de Lausanne, Swit-zerland"Engineering issues related to listening areas"

– M. Fink, ESPCI - LOA, Paris, France"New perspectives on time reversal acoustics"

Sessions spécialiséesLes sessions suivantes sont composées de contributions invitéeset ont été organisées par des experts dans leur domaine :– Active control (A. Jakob)– Applications of psychoacoustics (H. Fastl, E. Parizet)– Assessment of noise exposure in the frame of the environmen-

tal noise directive (V. Irmer)– Audiovisual interaction (C. Patsouras)– Auralisation (M. Vorländer, C. Semidor)– Benchmarking tests in automobile industry (K. Genuit)– Car acoustics (1) (U. Widmann)– Car acoustics (2) (H. E. Meier)– Car acoustics perception (E. Parizet, M. Lewit)– Car acoustics physical aspects (E. Parizet, M. Lewit)– Cavitation (B. Dubus, W. Lauterborn)– Change detection and repetition detection in hearing (L. De-

many, C. Kaernbach)– Combined noise evaluation (B. Schulte-Fortkamp)– Concert hall acoustics (S. Weinzierl)– Environmental noise and machinery noise– Flow noise (W. Neise)– Hydroacoustics (A. Homm)– Integrated micromechanical Si microphones for array applica-

tions (G. Sessler, )– Localization of normal hearing and hearing impaired persons

(O. Warusfel, B. U. Seeber– Low frequency vibrations– Low noise traffic (B. Griefahn)– Measuring methods in building acoustics (W. Scholl)– Medical Acoustics (F. Padilla)– Noise from leisure activities (B. W. Hohmann)– Non linear acoustics (V. Gusev)– Numerical methods in acoustics (O. von Estorff, J.-L. Guyader,

M. Ochmann)– Organ and room (J. Meyer)– Outdoor sound localisation (B. U. Seeber, P. Naz)– Outdoor sound propagation (D. Heimann, B. Gauvreau)– Physical acoustics (1) (W. Lauterborn)


– Physical acoustics (2) (C. Aristegui)– Picosecond acoustics – laser ultrasonics (A. Devos)– Psychoacoustical methods in musical acoustics (Gunter Zie-

genhals)– Railway noise (B. W. Hohmann)– Railway noise (2) (P.-E. Gautier)– Rating methods in building acoustics (A. Schmitz)– Recent advances in speech quality modeling (S. Moeller)– Room acoustics : simulation, measuring techniques and aura-

lisation (H. P. Tennhardt)– Silencers (U. Kurze)– Sleep, noise, and health (C. Maschke)– Sonic boom (P. Blanc-Benon, D. Heimann)– Soundscapes and community noise (B. Schulte-Fortkamp,

C. Marquis-Favre, K. Genuit)– Sound reinforcement and immission control (W. Ahnert)– Speech and voice – analysis and synthesis (M. Kob, X. Pelor-

son)– Speech in vehicles (H.-W. Gierlich)– Temporal aspects in the perception of sound and speech qua-

lity (A. Raake, S. Meunier)– Temporal envelope processing in hearing (C. Lorenzi, T. Dau)– Thermo- and flowacoustics (M. Ochmann, R. Piscoya,

P. Költzsch)– Vibration from railway lines (R. Wettschureck)– Wave field synthesis (G. Theile)– Ultrasonics Transducers (G. Feuillard)– Ultrasonic non destructive testing (A. Lhemery)– Underwater acoustics (G. Maze)

Salon européen d’acoustiqueLe congrès commun CFA/DAGA’04 aura lieu au Palais desCongrès de Strasbourg du 22 au 25 mars 2004. L’expositionréunit tous les fournisseurs importants de produits acoustiques,de services et d’information. L’exposition permettra aux entre-prises, aux industries, aux sociétés de service, d’informer les vi-siteurs de leurs résultats les plus récents dans le domaine de larecherche, du développement, des équipements, leurs méthodesinnovatrices, les solutions logicielles, matérielles, les standards,directives et publications.Des salles de conférence bien équipées et un grand espaced’exposition offrent les conditions parfaites pour la réussite ducongrès pour tous ceux qui s’intéressent à l’acoustique en Alle-magne, en France et en Suisse ainsi que dans les autres payseuropéens ou non.


Assemblée générale des membres de la DEGALe jeudi 25 mars après-midi, se tiendra l’assemblée générale2004 de la DEGA. Merci de bien vouloir prendre note de cettedate si vous souhaitez y participer. La lettre d’invitation officielleet le planning seront publiés dans le prochain numéro de "Spra-chrohr"de la DEGA.

Inscription au congrèsIl est vivement préférable de s’inscrire par l’intermédiaire site duWeb de la conférence, accessible depuis la page d’accueil

http ://www.cfadaga04.orgSociété Française d’Acoustique (SFA)23 avenue Brunetière75017 Paristél : +33 (0)1 48 88 90 59fax :+33 (0)1 48 88 90 60mél : [email protected]

Prix d’inscription

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1(5) non non non 330,- 360,-2 non non non 320,- 350,-3 non non oui 240,- 270,-4 oui non non 250,- 280,-5 oui non oui 125,- 155,-6 non oui non 100,- 110,-7 oui oui non 50,- 60,-(1) : Adhérent de la DEGA, SFA, SGA, VDI, DPG, ITG, VdT(2) : Les tarifs pour les "retraités"s’appliquent également aux personnes

sans revenus(3) : Inscription avant le 31 janvier 2004(4) : Inscription tardive après le 1er février 2004(5) : Lot : inscription et nouvelle adhésion à la SFA pour l’année 2004

L’offre spéciale (groupe 1) réservée aux non-membres de laSFA, inclut les frais d’inscription au congrès, ainsi que le droit


d’adhésion à la SFA pour l’année 2004. Cette offre est très attrac-tive en raison de la faible différence par rapport aux frais d’ins-cription seuls. Au-delà de 2004, l’adhésion à la SFA sera automa-tiquement reconduite chaque année, sous réserve de paiementdes droits d’adhésion standards. Si vous n’êtes pas intéressé parla poursuite de cette adhésion, un courrier devra être transmis ausecrétariat de la SFA début décembre 2004.

Inscription - Exposition européenne d’acoustique :Pour plus d’informations, veuillez contacter :Cécile Rodet Diana Schreiber01dB Acoustics & Vibration HEAD acoustics GmbH200 chemin des ormeaux Postfach 3340F-69760 Limonest D-52120 HerzogenrathTel. :+33 (0) 472-5247 80 Tel. : +49 (0) 2407-577 20Fax : +33 (0) 472-5247 88 Fax : +49 (0) 2407-577 99

e-mail : [email protected] ://www.cfadaga04.org

Actes du congrèsLes manuscrits des contributions (présentations orales et pos-ters) ne seront pas fournis à tous les participants sous formepapier, mais sous forme CD-ROM. Chaque participant inscrit re-cevra une copie de ce CD-ROM durant l’été 2004 automatique-ment.Une version papier des actes sera disponible pour un montantde 50 EURO, à condition que la commande soit transmise avantla fin du congrès. Au-delà, le montant de la version papier desactes sera de 75 EURO.

Instructions pour les présentationsIl est fortement recommandé que les présentations soient faitesen anglais, afin d’accroître au maximum l’audience possible.Néanmoins, les présentations en allemand ou français sont ac-ceptées. Toutes les figures doivent être organisés de façon claire(indépendemment de la langue utilisée).

PostersTous les posters seront présentés dans des sessions séparées,parallèlement aux sessions orales. Les auteurs des posters de-vront être présents au cours de leur session, afin de permettredes discussions avec les personnes intéressées. De même quepour les présentations orales, les sessions posters apparaîtrontdans le programme du congrès, avec les résumés correspon-dants.Les posters seront accrochés sur des panneaux pleins, de cotesutiles : hauteur : 2,39 m - largeur : 0,94 m. Ils se fixent sur leur


support par du ruban adhésif (non fourni) simple ou double face.Format recommandé pour les posters : A0.Les emplacements des posters seront identifiés par le n˚ cor-respondant aux auteurs / le nom de l’auteur / le titre du poster,placés sur le panneau correspondant.

Présentation oraleLes présentations durent 15 minutes, suivies d’une discussion de3 minutes. Une coupure de 2 minutes entre les présentations estprévue pour changer de salle.

Equipement audio-visuelDans chaque salle seront mis à la disposition des participants :– un ordinateur portable avec Windows 98 ou version supé-

rieure, Microsoft Power Point 2000, Adobe Acrobat Reader6.0, OpenOffice 1.1., java run-time environment 1.4,

– un vidéoprojecteur,– un rétroprojecteur.La lecture des CD se fera à partir de l’ordinateur portable de lasalle qui sera relié à la régie son. Il n’y aura pas de lecteur de CDaudio disponible dans les salles.Aucun projecteur de diapositives classiques, ni aucun systèmed’enregistrement / lecture sur bande magnétique (audio ou vi-déo) ne seront fournis. Au besoin, apportez votre propre appareilet le câblage nécessaire. (Entrées son : XLR) Auquel cas il estabsolument nécessaire d’en informer l’organisateur au préalableavant le 1er mars 2004 en indiquant le n˚ de la session (Mail to :[email protected]).Attention : les prises secteur ne sont pas identiques dans tousles pays européens.Aucune demande d’intervention avec du matériel particulier(même s’il est fourni par le participant) pendant le congrès nesera prise en compte.Une salle de Preview avec 2 PC sera mise à disposition descongressistes pour contrôler leur présentation.

RecommandationsIl est très fortement conseillé de venir avec 1 CD Rom ou une dis-quette contenant la présentation. L’utilisation de USB sticks n’estpas garantie par l’organisateur. La présentation sera chargée surl’ordinateur avant le début de chaque session.Si la présentation est faite à partir d’un ordinateur portable, il estrecommandé d’imprimer la présentation sur transparents afin depouvoir faire face à des problèmes techniques.Il sera possible d’utiliser son propre ordinateur à ses propresrisques. L’ordinateur pourra être branché sur le vidéoprojecteurde la salle.


Les participants sont responsables de leur présentation.Il ne sera pas accordé de temps supplémentaire aux intervenantsdont les présentations ne sont pas opérationnelles.

ManuscritsLe manuscrit final est limité à 2 pages maximum doublecolonnes, selon un format PDF. Le manuscrit devraêtre transmis soit avant le congrès, soit sur place pren-dant la conférence ; dans tous les cas, la date limiteest fixée au 25 mars 2004. Des modèles de documentaux formats Winword et LATEX 2ε sont disponibles sur :

http ://www.cfadaga04.org/presentation_guide_f.html

LogementLes participants au congrès sont invités à veiller à leur logementsur place. Vous pouvez contacter l’office de tourisme pour touteassistance dans la recherche d’un logement. De plus amplesinformations, ainsi que des possibilités de réservation en ligne,sont disponibles à l’adresse suivante :Office du tourisme de Strasbourg17 place de la CathédraleB.P. 70020F–67082 Strasbourg cedexTel : +33(0)3 88 52 28 28Fax : +33(0)3 88 52 28 29http ://www.ot-strasbourg.fr/ou par l’intermédiaire du palais des congrès : un formulaire desréservation hôtelière hotel.pdf peut être téléchargé sur

http ://www.cfadaga04.org/venue_f.html

Dates importantes pour CFA/DAGA’04– Février 2004 :

Programme prêt et disponible par Internet, envoi postal de laversion papier

– 22 – 25 mars 22 2004 :Congrès CFA/DAGA‘04,Date limite de soumission des articles sur le site Web ducongrès

– Eté 2004 :Envoi des CD-ROM et des actes au format papier


Hinweise zur Tagung


7ème Congrès Français d’AcoustiqueDie 30. Deutsche Jahrestagung für Akustik findet zusammen mitdem 7. Congrès Français d’Acoustique als deutsch/französischeGemeinschaftstagung

vom 22. bis 25. März 2004in Straßburg (Frankreich) im dortigen Kongresszentrum statt.

TagungsortDer Tagungsort ist das Kongresszentrum in Straßburg. Sei-ne zentrale geographische Lage wie auch seine bewegtedeutsch/französische Geschichte haben Straßburg zu einemZentrum Europas und zum Symbol einer freundschaftlichenNachbarschaft und Kooperation gemacht. Straßburg ist eine derwenigen Städte der Welt, deren vollständiges Zentrum zum Welt-kulturerbe erklärt wurde.Das Kongresszentrum ist in 10 Minuten vom historischen Zen-trum zu erreichen. Dort bieten bestens ausgestattete Hörsäle so-wie eine ausgedehnte Ausstellungsfläche ideale Voraussetzun-gen für eine erfolgreiche Begegnung aller an der Akustik Interes-sierten aus Deutschland, Frankreich und der Schweiz sowie ausanderen europäischen und außereuropäischen Ländern.Adresse:Kongresszentrum StraßburgPlace de Bordeaux – Wacken –F–67082 Strasbourg CedexWeitere Information finden Sie unterhttp://www.strasbourgmeeting.com

VeranstalterVeranstalter der Tagung sind die akustischen GesellschaftenDeutschlands und Frankreichs, DEGA und SFA, mit Unterstüt-zung der Schweizerischen Akustischen Gesellschaft SGA–SSAin Zusammenarbeit mit der Informationstechnischen Gesellschaftim VDE (ITG), dem Normenausschuss Akustik, Lärmminderungund Schwingungstechnik (NALS) im DIN und im VDI und derDeutschen Physikalischen Gesellschaft (DPG).

Tagungsleitung und Organisation

Die wissenschaftliche Tagungsleitung liegt bei

Jacques Châtillon und Joachim Scheuren.

Sie werden unterstützt von:


TagungskoordinationDelphine Noël Alfred Schmitz

Registrierung und SekretariatEvelyne Dewayse Regina Condin, Christian Nocke

Europäische Akustik-AusstellungClaude Legros (Koordination)


FinanzenJacques Châtillon Hugo Fastl

Publikation und InternetDidier Cassereau Malte Kob

ProgrammausschussArmand Dancer (Leitung) Michael MöserHenri Arbey Heinz-Martin FischerJean Louis Guyader Armin KohlrauschJean Kergomard Wolfgang Kropp


Lokale UnterstützungGuillaume Dutilleux, Catherine Serve Rainer Riedlinger

Technische KoordinationJoachim Feldmann

TagungssprachenTagungssprachen sind bevorzugt Englisch, aber auch Deutschund Französisch.

Themen der TagungThemen der Tagung sind alle Gebiete der Akustik sowie alleFachgebiete, die interdisziplinär mit der Akustik verbunden sind,in diesem Jahr insbesondere die folgenden: Audiologische Aku-stik, Aktive Schallbeeinflussung, Bauakustik, Bioakustik, Elektro-akustik, Fahrzeugakustik, Hydro- und Geoakustik, Körperschall,Lärmausbreitung, Lärmschutz, Messtechnik, Musikalische Aku-stik, Numerische Akustik, Physikalische Akustik, Psychoaku-stik, Raumakustik, Signalverarbeitung, Sprachverarbeitung, Ul-traschall

PlenarvorträgeEingeladene Vortragende halten Übersichtsvorträge zu aktuellenThemen von allgemeinem Interesse:• P. Avan, Faculté de Médecine, Clermont-Ferrand, France

Äuditory distortion: toward a non-invasive dissection of coch-lear micromechanics"

• H.-E.Meier, DaimlerChrysler AG, Germany"Vehicle acoustics: chances for application of research results"


• M. Rossi, Ecole Polytechnique Fédérale de Lausanne, Swit-zerlandËngineering issues related to listening areas"

• M. Fink, ESPCI - LOA, Paris, FranceNew perspectives on time reversal acoustics"

Strukturierte SitzungenDie Strukturierten Sitzungen wurden von fachkundigen Organi-satoren aus eingeladenen Beiträgen zusammengesetzt.• Active control (A. Jakob)• Applications of psychoacoustics (H. Fastl, E. Parizet)• Assessment of noise exposure in the frame of the environmen-

tal noise directive (V. Irmer)• Audiovisual interaction (C. Patsouras)• Auralisation (M. Vorländer, C. Semidor)• Benchmarking tests in automobile industry (K. Genuit)• Car acoustics (1) (U. Widmann)• Car acoustics (2) (H. E. Meier)• Car acoustics perception (E. Parizet, M. Lewit)• Car acoustics physical aspects (E. Parizet, M. Lewit)• Cavitation (B. Dubus, W. Lauterborn)• Change detection and repetition detection in hearing (L. De-

many, C. Kaernbach)• Combined noise evaluation (B. Schulte-Fortkamp)• Concert hall acoustics (S. Weinzierl)• Environmental noise and machinery noise• Flow noise (W. Neise)• Hydroacoustics (A. Homm)• Integrated micromechanical Si microphones for array applica-

tions (G. Sessler, )• Localization of normal hearing and hearing impaired persons

(O. Warusfel, B. U. Seeber• Low frequency vibrations• Low noise traffic (B. Griefahn)• Measuring methods in building acoustics (W. Scholl)• Medical Acoustics (F. Padilla)• Noise from leisure activities (B. W. Hohmann)• Non linear acoustics (V. Gusev)• Numerical methods in acoustics (O. von Estorff, J.-L. Guyader,

M. Ochmann)• Organ and room (J. Meyer)• Outdoor sound localisation (B. U. Seeber, P. Naz)• Outdoor sound propagation (D. Heimann, B. Gauvreau)• Physical acoustics (1) (W. Lauterborn)• Physical acoustics (2) (C. Aristegui)• Picosecond acoustics – laser ultrasonics (A. Devos)• Psychoacoustical methods in musical acoustics (Gunter Zie-

genhals)• Railway noise (B. W. Hohmann)


• Railway noise (2) (P.-E. Gautier)• Rating methods in building acoustics (A. Schmitz)• Recent advances in speech quality modeling (S. Moeller)• Room acoustics: simulation, measuring techniques and aura-

lisation (H. P. Tennhardt)• Silencers (U. Kurze)• Sleep, noise, and health (C. Maschke)• Sonic boom (P. Blanc-Benon, D. Heimann)• Soundscapes and community noise (B. Schulte-Fortkamp,

C. Marquis-Favre, K. Genuit)• Sound reinforcement and immission control (W. Ahnert)• Speech and voice – analysis and synthesis (M. Kob, X. Pelor-

son)• Speech in vehicles (H.-W. Gierlich)• Temporal aspects in the perception of sound and speech qua-

lity (A. Raake, S. Meunier)• Temporal envelope processing in hearing (C. Lorenzi, T. Dau)• Thermo- and flowacoustics (M. Ochmann, R. Piscoya,

P. Költzsch)• Vibration from railway lines (R. Wettschureck)• Wave field synthesis (G. Theile)• Ultrasonics Transducers (G. Feuillard)• Ultrasonic non destructive testing (A. Lhemery)• Underwater acoustics (G. Maze)

Europäische Akustik AusstellungDie Tagung wird von einer großen europäischen Akustik-Ausstellung begleitet, die alle wichtigen Anbieter akustischerProdukte, Dienstleistungen und Informationen vereint. In die-ser Ausstellung informieren Firmen, Hersteller, Ingenieurdienst-leister, aber auch Forschungs- und Verwaltungseinrichtungen,technisch-wissenschaftliche Vereinigungen und Verlage überneueste Ergebnisse in Forschung und Entwicklung, über Gerä-te, Verfahren und Softwarelösungen sowie Materialien und Werk-stoffe, Normen, Richtlinien und Publikationen.Die Ausstellung wird abgehalten in den breiten Gängen zwischenden Hörsälen des Konferenzzentrums. Mehr als 1000 Teilnehmerwerden die Stände durchqueren, um die Räume zu erreichen.

AbschlussveranstaltungIm Rahmen der Abschlussveranstaltung der CFA/DAGA’04 wirdder Preis für das beste Poster verliehen. Anschliessend findet dieDEGA-Mitgliederversammlung statt.

DEGA-MitgliederversammlungAm Donnerstagnachmittag, dem 25. März 2004 um 16:30 Uhr,wird die DEGA-Mitgliederversammlung stattfinden. Bitte merken


Sie sich den Termin vor. Die offizielle Einladung und die Tages-ordnung gehen den Mitgliedern der DEGA mit dem nächstenSprachrohr kurz vor der CFA/DAGA’04 zu.

Anmeldung zur TeilnahmeDie Anmeldung zur Teilnahme soll vorzugsweise per Internet un-ter

http://www.cfadaga04.orgerfolgen. Ein online Anmeldeformular steht auf der Web-Seite zurVerfügung. Für die schriftliche Anmeldung als Teilnehmer benut-zen Sie bitte das Anmeldeformular (siehe Seite 487), das eben-falls von der Webseite herunter geladen oder bei der DEGA-Geschäftsstelle angefordert werden kann.DEGA GeschäftsstelleDr. Christian Nockec/o Universität OldenburgPhysik - AkustikD-26111 OldenburgTel.: +49 (0) 441 798-3561Fax: +49 (0)441 798-3698e-mail: [email protected]: http://www.cfadaga04.org

TeilnahmegebührenDie Teilnahmegebühren entnehmen Sie bitte der Tabelle auf Sei-te 36.Das Paketangebot (Preisgruppe 1) für Nicht–DEGA– Mitgliederumfasst neben der Tagungsteilnahme die volle persönliche Mit-gliedschaft in der DEGA inklusive des Mitgliedsbeitrags für 2004.Dieses Paketangebot ist auf Grund der geringen Differenz zurregulären Teilnahmegebühr sehr attraktiv. Nach Ablauf dem Jahr2004 verlängert sich die Mitgliedschaft automatisch. Es geltendann die regulären Mitgliedsbeiträge. Sollten Sie an einer wei-terführenden Mitgliedschaft nicht interessiert sein, teilen Sie unsdieses bis spätestens vier Wochen vor Ablauf des Jahres schrift-lich mit.

Anmeldung – Europäische Akustik AusstellungCécile Rodet Diana Schreiber01dB Acoustics & Vibration HEAD acoustics GmbH200 chemin des ormeaux Postfach 3340F-69760 Limonest D-52120 HerzogenrathTel.:+33 (0) 472-5247 80 Tel.: +49 (0) 2407-577 20Fax: +33 (0) 472-5247 88 Fax: +49 (0) 2407-577 99

e-mail: [email protected]://www.cfadaga04.org


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DEGA im Jahr 2004

Tagungs-CD und TagungsbandDie Manuskripte der Beiträge zur Tagung (Vorträge und Poster)werden standardmäßig nicht mehr als gedruckter Tagungsband,sondern als CD-ROM veröffentlicht. Jeder registrierte Tagungs-teilnehmer erhält diese CD-ROM im Sommer 2004. Eine ge-druckte Version des Tagungsbandes ist selbstverständlich weitererhältlich, allerdings gegen eine Kostenbeteiligung von 50 EU-RO. Dieser Preis gilt als Subskriptionspreis bei Bestellung voroder während der Tagung. Nachträgliche Bestellungen des Ta-gungsbandes sind möglich; der Preis beträgt dann 75 EURO.

Präsentationsformen der BeiträgeUm eine bestmögliche Verständlichkeit für einen größtmöglichenInteressentenkreis zu erreichen, wird empfohlen, die Beiträge inenglischer Sprache abzufassen und vorzutragen. Dennoch blei-ben auch Beiträge in französischer oder deutscher Sprache zu-gelassen.Um für alle Sprachen eine Mindestverständlichkeit zu erreichen,sollen alle Abbildungen und Präsentationsfolien besonders über-sichtlich und weitgehend selbsterklärend (von der Sprache unab-hängig) gestaltet sowie in englischer Sprache beschriftet werden.

PosterAlle Poster werden in eigenen Sitzungsperioden parallel zu denVortragsperioden vorgestellt. Während dieser Sitzungen haltensich die jeweiligen Autoren am Präsentationsort zu Erklärungenund Diskussionen bereit.


Auch im Tagungsprogramm werden Postersitzungen gleichrangigzu den anderen Sitzungen mit einer Kurzfassung aufgeführt.Für die Posterausstellung werden Stellwände bereitgestellt, andenen die Poster präsentiert werden. Für jedes Poster steht eineFläche von max. 94 cm (Breite) x 239 cm (Höhe) zur Verfügung.Befestigungsmaterial wird zur Verfügung gestellt. Als Größe derPoster wird A0 empfohlen.

Mündlicher VortragDie Vorträge haben eine Dauer von 15 Minuten. Es schließt sicheine 3-minütige Diskussionszeit an. Da die Konferenzräume alleuntereinander gut erreichbar sind, ist eine Pause von nur 2 Minu-ten für den Raumwechsel ausreichend.

Audio. und ComputerpräsentationIn jedem Vortragsraum ist standardmäßig die folgende Aussat-tung vorhanden• a laptop mit Betriebssystem Windows 98 oder höher, Microsoft

Power Point 2000, Adobe Acrobat Reader 6.0, OpenOffice 1.1(java run-time environment 1.4 included),

• ein Video-Beamer,• ein Overhead-Projektor.CDs (or andere Sounds) werden auf dem Laptop im jeweiligenRaum über die installierte PA-Anlage abgespielt. CD-Spieler sindin den Vortragsräumen nicht vorhanden.Ebenfalls nicht vorhanden sind 35 mm Diaprojektoren oderKassetten- und Video-Rekorder.Sofern benötigt, bringen Sie bitte Ihre eigene Ausstattung mit(XLR-Kabel). Für diesen Fall geben Sie den Organisatoren bit-te bis zum 1. März 2004 unter der Angabe der Sitzung Bescheid(e-mail: [email protected]). Achtung: Andere Netz-stecker in Frankreich.Anfragen zu speziellen Anforderungen an die Präsentationstech-nik können nach Beginn der Tagung leider nicht mehr berücksich-tigt werden, auch wenn der/die Vortragende ein eigenes Gerätmitbringt.Ein Vorschau-Raum mit 2 PCs steht den Tagungsteilnehmernzum Ausprobieren der eigenen Präsentationen zur Verfügung.

EmpfehlungenEs wird empfohlen die eigenen Präsentation lauffertig auf CD-ROM oder Floppy-Disk (im Format .ppt oder Pack&Go – .ppsoder pdf) mitzubringen. Somit können die Präsentationen vor Be-ginn der jweiligen Sitzungen auf den vorhandenen Laptop über-spielt werden.Die Verwendung von USB-Sticks wird seitens der Tagungsleitungnicht garantiert.Nutzen Sie die Möglichkeit, Ihre Präsentation vorab auszuprobie-ren, falls etwas nicht klar erscheint. Sicherheitshalber sollten Sie


gegebenenfalls einen Ausdruck auf Overhead-Folien mitbringen,um eventuelle technische Probleme vermeiden zu können.Eigene Laptops können in eigener Verantwortung verwendetwerden. Prinzipiell ist das Anschliessen eigener Laptops in je-dem Vortragsraum möglich.Generell gilt, dass die Tagungsteilnehmer für die Präsentati-on selber verantwortlich sind. Bei Verzögerungen durch tech-nische Probleme kann die Vortragsdauer aufgrund des engenZeitrasters nicht nachgeholt werden.

ManuskripteDas Manuskript soll eine Länge von zwei Seiten haben undals zweispaltiges pdf-Dokument abgefasst sein. Das Manuskriptmuss spätestens zur Tagung eingereicht werden (Abgabefrist:25.03.2004). Eine Vorlage im Word- und LATEX 2ε-Format wird be-reitgestellt unter:

http://www.cfadaga04.org/presentation_guide_d.htmlAutoren ohne Zugang zum Internet wenden sich gerne an dieDEGA-Geschäftsstelle, Adrresse siehe Seite 35

UnterkunftDie Reservierung von Unterkünften bleibt den Tagungsteilneh-mern selbst überlassen. Dabei steht es jedem frei, bei der Bu-chung einer geeigneten Unterkunft auf das örtliche Fremdenver-kehrsbüro zurückzugreifen.Weitere Informationen und online-Buchungsmöglichkeiten findensich unter: Tourism Office of Strasbourg17 place de la CathédraleB.P. 70020F–67082 Strasbourg cedexTel : +33(0)3 88 52 28 28Fax : +33(0)3 88 52 28 29http://www.ot-strasbourg.fr/oder über das Kongresszentrum: ein Formular zur Hotel-Reservierung hotel.pdf ist unter

http://www.cfadaga04.org/venue_d.htmlerhältlich.

Wichtige Termine zur CFA/DAGA‘04• Februar 2004: Versand des Programms an die angemeldeten

Teilnehmer, Programm im Internet• 22. März – 25. März 2004: CFA / DAGA‘04-Tagung, Abgabe

der druckfertigen Tagungsbeiträge in elektronischer Form alspdf-Datei (vorzugsweise vorab per Internet)

• Sommer 2004: Versand der CD-ROM sowie der zusätzlich ge-orderten gedruckten Tagungsbände (kostenpflichtig)


General information


7ème Congrès Français d’AcoustiqueThe 30th German Convention on Acoustics (DAGA) takes placetogether with the 7th Congrès Français d’Acoustique (CFA) as ajoint French-German meeting 22.-25 March 2004 in Strasbourg(France).

Conference siteIts central geographic location as well as its turbulent ger-man/french history made Strasbourg a European centre and asymbol of a friendly neighbourhood and cooperation. Strasbourgis one of the few towns of which the centre has been declared aworld-heritage.The congress centre is located 10 minutes walking distance fromthe historic centre. The well-equipped auditoria and the large ex-position area provide ideal conditions for a successful meeting ofall people interested in acoustics whether they come from Ger-many, France, Swiss or other European or Non-European coun-tries.Address:Strasbourg Music and Conference CentrePlace de Bordeaux – Wacken –F–67082 Strasbourg CedexFurther information is available at:http://www.strasbourgmeeting.com

OrganisersThe congress is jointly organised by the acoustical societiesof Germany and France, DEGA and SFA, with support by theSwiss Acoustical Society SGA–SSA in co-operation with the "In-formationstechnische Gesellschaft im VDE"(Information Technol-ogy Section, ITG, within the German Association for Electrical,Electronic & Information Technologies, VDE), the NALS "Norme-nausschuss Akustik, Lärmminderung und Schwingungestech-nik"(German Standards Committee Acoustics, Noise Reductionand Vibration) of DIN and VDI and the "Deutsche PhysikalischeGesellschaft"(German Physical Society, DPG).

Scientific conference chair and organising committee

The congress is chaired by

Jacques Châtillon and Joachim Scheuren.

They are supported by:


Coordination of the congressDelphine Noël Alfred Schmitz

Registration and secretariatEvelyne Dewayse Regina Condin, Christian Nocke

European acoustics exhibitionClaude Legros (coordination)


FinancesJacques Châtillon Hugo Fastl

Publication and InternetDidier Cassereau Malte Kob

Scientific committeeArmand Dancer (session organisers) Michael MöserHenri Arbey Heinz-Martin FischerJean Louis Guyader Armin KohlrauschJean Kergomard Wolfgang Kropp


Local supportGuillaume Dutilleux, Catherine Serve Rainer Riedlinger

Technical coordinationJoachim Feldmann

LanguagesEnglish will be the preferred language of the congress but alsoGerman and French are welcome.

Topics of the CongressTopics of the conference are all areas of acoustics, and all ar-eas which are inter-disciplinarily related to acoustics, in particu-lar the following: audiology, active noise control, building acous-tics, bioacoustics, electroacoustics, vehicle acoustics, hydro- andgeoacoustics, structure-borne sound, noise propagation, noisecontrol, metrology, musical acoustics, numerical acoustics, phys-ical acoustics, psychoacoustics, room acoustics, signal process-ing, speech processing and ultrasonics.

Plenary lecturesInvited lectures will focus on hot topics of general interest:• P. Avan, Faculté de Médecine, Clermont-Ferrand, France

"Auditory distortion: toward a non-invasive dissection ofcochlear micromechanics"

• H.-E.Meier, DaimlerChrysler AG, Germany"Vehicle acoustics: chances for application of research results"


• M. Rossi, Ecole Polytechnique Fédérale de Lausanne,Switzerland"Engineering issues related to listening areas"

• M. Fink, ESPCI - LOA, Paris, France"New perspectives on time reversal acoustics"

Structured sessionsThe following structured sessions are composed of invited con-tributions and have been organised by experts:• Active control (A. Jakob)• Applications of psychoacoustics (H. Fastl, E. Parizet)• Assessment of noise exposure in the frame of the environmen-

tal noise directive (V. Irmer)• Audiovisual interaction (C. Patsouras)• Auralisation (M. Vorländer, C. Semidor)• Benchmarking tests in automobile industry (K. Genuit)• Car acoustics (1) (U. Widmann)• Car acoustics (2) (H. E. Meier)• Car acoustics perception (E. Parizet, M. Lewit)• Car acoustics physical aspects (E. Parizet, M. Lewit)• Cavitation (B. Dubus, W. Lauterborn)• Change detection and repetition detection in hearing (L. De-

many, C. Kaernbach)• Combined noise evaluation (B. Schulte-Fortkamp)• Concert hall acoustics (S. Weinzierl)• Environmental noise and machinery noise• Flow noise (W. Neise)• Hydroacoustics (A. Homm)• Integrated micromechanical Si microphones for array applica-

tions (G. Sessler, )• Localization of normal hearing and hearing impaired persons

(O. Warusfel, B. U. Seeber• Low frequency vibrations• Low noise traffic (B. Griefahn)• Measuring methods in building acoustics (W. Scholl)• Medical Acoustics (F. Padilla)• Noise from leisure activities (B. W. Hohmann)• Non linear acoustics (V. Gusev)• Numerical methods in acoustics (O. von Estorff, J.-L. Guyader,

M. Ochmann)• Organ and room (J. Meyer)• Outdoor sound localisation (B. U. Seeber, P. Naz)• Outdoor sound propagation (D. Heimann, B. Gauvreau)• Physical acoustics (1) (W. Lauterborn)• Physical acoustics (2) (C. Aristegui)• Picosecond acoustics – laser ultrasonics (A. Devos)


• Psychoacoustical methods in musical acoustics (GunterZiegenhals)

• Railway noise (B. W. Hohmann)• Railway noise (2) (P.-E. Gautier)• Rating methods in building acoustics (A. Schmitz)• Recent advances in speech quality modeling (S. Moeller)• Room acoustics: simulation, measuring techniques and aural-

isation (H. P. Tennhardt)• Silencers (U. Kurze)• Sleep, noise, and health (C. Maschke)• Sonic boom (P. Blanc-Benon, D. Heimann)• Soundscapes and community noise (B. Schulte-Fortkamp,

C. Marquis-Favre, K. Genuit)• Sound reinforcement and immission control (W. Ahnert)• Speech and voice – analysis and synthesis (M. Kob, X. Pelor-

son)• Speech in vehicles (H.-W. Gierlich)• Temporal aspects in the perception of sound and speech qual-

ity (A. Raake, S. Meunier)• Temporal envelope processing in hearing (C. Lorenzi, T. Dau)• Thermo- and flowacoustics (M. Ochmann, R. Piscoya,

P. Költzsch)• Vibration from railway lines (R. Wettschureck)• Wave field synthesis (G. Theile)• Ultrasonics Transducers (G. Feuillard)• Ultrasonic non destructive testing (A. Lhemery)• Underwater acoustics (G. Maze)

European acoustics exhibitionParallel to the congress a large European Acoustics exhibitionwill be held. The exhibition joins all important providers of acous-tical products, services and information. At the exhibition com-panies, manufacturers, engineering services providers, but alsoresearch and administrative establishments, technical-scientificassociations and publishers inform about the newest results inresearch and development concerning equipment, technologiesand software solutions as well as materials, standards, regula-tions and publications.Well equipped lecture rooms and a large exhibition space pro-vides perfect conditions for a successful meeting for everybodyinterested in acoustics from Germany, France and Switzerlandas well as from other European or non-European countries.

DEGA members general assemblyOn Thursday afternoon, March 25, the 2004 general assem-bly of DEGA will take place. Please note this date if you areinterested in participating. The official invitation letter and theagenda will be published in the upcoming "Sprachrohr"newsletterof DEGA.


Conference registrationPreferably, registration should be done via the conference web-site, which can be reached from the congress homepage

http://www.cfadaga04.orgAlternatively, you can register via a hard copy of the registrationform which is added to this brochure (see page 487) or can befound on the website.DEGA GeschäftsstelleDr. Christian Nockec/o Universität OldenburgPhysik - AkustikD-26111 OldenburgTel.: +49 (0) 441 798-3561Fax: +49 (0)441 798-3698e-mail: [email protected]: http://www.cfadaga04.org

Registration fees

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1(5) no no no 330,- 360,-2 no no no 320,- 350,-3 no no yes 240,- 270,-4 yes no no 250,- 280,-5 yes no yes 125,- 155,-6 no yes no 100,- 110,-7 yes yes no 50,- 60,-(1): Member of DEGA, SFA, SGA–SSA, VDI, DPG, ITG, VdT(2): Membership fee "pensioner"is also applicable for unemployed.(3): Fee until Jan. 31, 2004(4): Fee after Feb. 1, 2004(5): special package: Participation at conference plus new membership

of DEGA in 2004, membership stays with extra costs from 2005

The special package (group 1) for non-members of DEGA in-cludes the conference fee and the full personal membership feefor 2004. This package is very attractive due to the small differ-ence between the regular fee. After 2004 for the membership willautomatically be continued. Then the usual membership fees aspersonal member of DEGA are due. If being not interested inthis membership, a short notice has to be given to DEGA by thebeginning of December 2004.


Registration – european acoustics exhibitionCécile Rodet Diana Schreiber01dB Acoustics & Vibration HEAD acoustics GmbH200 chemin des ormeaux Postfach 3340F-69760 Limonest D-52120 HerzogenrathTel.:+33 (0) 472-5247 80 Tel.: +49 (0) 2407-577 20Fax: +33 (0) 472-5247 88 Fax: +49 (0) 2407-577 99

e-mail: [email protected]://www.cfadaga04.org

Congress proceedingsThe manuscripts of the contributions (oral and poster presenta-tions) will generally not be published as as printed version but onCD-ROM. Every registered participant will obtain a copy of thisCD-ROM during summer 2004 automatically. A printed versionof the proceedings will be made available at a rate of 50 EURO-for orders received until the end of the conference. Later ordersare possible at a rate of 75 EURO.

Guidelines for presentationsIt is highly recommended that presentations be done in Englishin order to reach as much of the audience as possible. How-ever presentations in German and French are allowed. All fig-ures should be created in a self-explanatory layout, the legendsshould also be in English. Generally, strange fonts should beavoided.

PosterAll posters will be presented in separate sessions parallel tothe oral presentation timetables. The authors of the respectiveposters will be present during their timetabled poster session andwill be prepared for discussions and clarifications. The postersessions are also printed with an abstract in the congress pro-gramme, just like the oral presentations.Posters will be hooked on full boards with: height: 2,39 m - width:0,94 m as useful dimensions. They can be fixed on their sup-port with adhesive tape (not provided), simple or double-faced.Recommended size for posters: A0.

Oral PresentationThe presentations last 15 minutes followed by a 3 minutes dis-cussion. A break of 2 minutes in between the presentations istimetabled to change between the rooms.


Audio and video equipmentIn each room, following equipment will be available:• a laptop with windows 98 or upper version, Microsoft Power

Point 2000, Adobe Acrobat Reader 6.0, OpenOffice 1.1 (javarun-time environment 1.4 included),

• a video projector (beamer),• an overhead projector.CDs (or sound) will be played from the room laptop, which will belinked to the room P.A. system. There won’t be any CD playeravailable in the session rooms.No conventional 35 mm slides projector and no recorder/playertape system (audio or video) will be available.If absolutely necessary, please bring your own device (cables in-cluded, sound : XLR) with you. In this case, it’s important toinform the organiser before the 1st March 2004 with regard toyour session. (mail to : [email protected])Warning : mains sockets can be different within the EU.Requests for presentation with particular devices during thecongress will not be taken into account, even if the attendeebrings his/her own device.A preview room with 2 PC will be available for attendees to checktheir presentation.

RecommendationsIt’s highly recommended to come to the performance with aCDROM or a floppy disk containing the presentation (Format .pptor alternative pack&go or .pdf). If this happens in time the pre-sentation can be downloaded on the laptop before the beginningof each session. The use of USB sticks is not guaranteed by theorganiser.Use the possibility to check the presentation before if somethingseems to be not clear.If the presentation is done with a laptop, it is recommended toprint out the presentation on overhead transparency sheets inorder to cope with potential technical problems.It will be possible to use one’s own laptop one’s own risks. Inprincipal it will be feasible to connect an external laptop to thevideo projector in each room, but the functioning of the presenta-tion technique is guaranteed only by the existing laptop/beamercombination.The attendees are responsible for their presentation. Presenterswhose presentations fail for any reason will not be granted extratime.

Guidelines for preparation of manuscriptsThe manuscripts shall have a length of two pages and shall beformatted as a two-column style pdf document. The manuscript


shall be submitted before or during the conference, latest March25, 2004. A template in Winword or LATEX 2εformat is available at:

http://www.cfadaga04.org/presentation_guide_e.htmlAuthors without access to the internet may contact the secreteriatof DEGA, address see page 35

AccomodationFor the reservation and booking of accommodation each partici-pants has to organise for him- or herself.Further information and online-booking facilities are available atTourism Office of Strasbourg17 place de la CathédraleB.P. 70020F–67082 Strasbourg cedexTel : +33(0)3 88 52 28 28Fax : +33(0)3 88 52 28 29http://www.ot-strasbourg.fr/or through the Congress Centre: a hotel.pdf registration form isavailable at:

http://www.cfadaga04.org/venue_e.html

Important dates for CFA/DAGA’04• February 2004:

Programme ready and available via internet, printed versionbeing sent

• March 22 – March 25 2004:CFA/DAGA‘04 Congress ,Deadline for submission of papers via congress website

• Sommer 2004:Dispatching of CD-ROM and additionally printed proceedings

CFA/DAGA’04 Jam SessionTuesday 23 March, from 19:00 hours Jam SessionAll participants and guests of CFA/DAGA ’04 are cordially invitedto join the CFA/DAGA Jam Session during the welcome evening.This traditional DAGA event shall give opportunity to play Jazzstandards with colleagues without rehearsing. If you are inter-ested to participate please bring your instrument with you. Youwill find piano, drum set and PA installed.Contact :

[ Malte Kob ([email protected]),] Joel Gilbert([email protected]) ou\ Xavier Pelorson ([email protected])


Opening CeremonyMo. 13:30 Schweitzer Opening of CFA/DAGA’04

• Welcome adresses

Plenary lecturesTu. 14:00 Schweitzer Plenary session 2

An overview of time-reversed acousticsMathias FinkESPCI - LOATime-reversal invariance is a very powerful concept in physics. Inthe field of acoustics, where time-reversal invariance also occurs,time-reversal experiments may be achieved simply with arrays oftransmit-receive transducers, allowing an incident acoustic fieldto be sampled, recorded, time-reversed, and re-emitted. Thetime-reversal mirrors (TRMs) are innovative tools in the field offundamental physics. They may be used to study random media,multiple scattering processes, chaotic scattering, inverse scatter-ing problems, dissipation effects, and diffraction limits. They openthe way to new signal processing. An overview of these fields willbe presented. Applications of TRMs will also be described, in-cluding underwater acoustics, medical applications, telecommu-nications, as well as nondestructive testing.

We. 11:10 Schweitzer Plenary session 3

Vehicle Acoustics: Chances for Application of Research Re-sultsHeinz-E. MeierDaimlerChrysler AGVehicle acoustics is (almost) not organized as an autonomousbranch of research. However, numerous principles and methodsof acoustics have been developed by research people regard-ing vehicle acoustics as one possible field of application. Ex-amples are Signal Analysis (analog and digital), Modal Analysis,Psychoacoustics, Statistical Energy Analysis (SEA), Active NoiseCancellation (ANC), Sound Intensity and many more. Some ofthese examples have become essential standard tools in vehicleacoustics, some exist on the fringes. The study of their history ofapplication and conversion leads to evidence of success factorswhich (co-) determine the chances for the application of a scien-tific idea or development result. It is mandatory for acousticiansas well as for automotive engineers to know these factors and tounderstand their different cultural view from the either partner’sside.


We. 11:55 Schweitzer Plenary session 4

Engineering Issues Related to Listening AreasMario RossiEcole Polytechnique Fédérale de LausanneThrough numerous real-life implementations and beyond the ex-pected responses to the various mandates, in terms of adequatesolutions, the author has always strived to contribute to the state-of-the-art of acoustical engineering. It should be underlined thatthe problems posed were out of the ordinary and as such, con-stituted severe challenges, where the will of the project managerand users was to have multifunctional spaces at their disposal.The latter are designed to host a variety of events ranging fromconferences, congresses, classical concerts, operas, drama, va-riety shows, jazz, pop music, exhibitions, worship, etc. The aimis to guarantee the best possible conditions for the hosting ofevents and not focus on their more or less successful coexis-tence. This implies defining and designing specific arrangementsand layouts. In most cases, the listening area was already in exis-tence, with both its qualities and faults, and it has to be adapted tonew usages. Also, the architectural or environmental constraintsare often such that the area does not satisfy the essential acous-tic criteria as regards volume and shape. The only possible andfruitful approach liable to succeed in responding to this challenge,is an epistemological approach, where critical scientific thinkingunderlies rigorous experimental methods. This presentation willshow that in acoustics, maybe more than in others fields, thereshould be no frontier between science and technique.

Th. 11:10 Schweitzer Plenary session 5

Auditory distortion: toward a non-invasive dissection ofcochlear micromechanicsPaul AvanFaculté de MédecineThe discovery of otoacoustic emissions (OAE) by Kemp hasbeen the most groundbreaking step in auditory physiology sinceBékésy’s. In the first place, the existence of OAEs underpinnedGold’s 1948 statement that the cochlea must work as a regen-erative looped system, with enhanced sensitivity and frequencyselectivity as a result. It is now known that the outer hair cells(OHC) house the regenerative loop, although which substruc-ture(s) exactly contribute is unclear. Secondly, OAEs provide ev-idence that in sharp contrast to most acoustic reproduction sys-tems, the cochlea is essentially nonlinear. So, intermodulationdistortion is generated and comes out as an OAE whenever the


cochlea is stimulated by pairs of pure, primary tones with neigh-boring frequencies. This property has been successfully usedfor probing OHCs and cochlear function around the place tunedto the primary stimuli, thereby disclosing strong correlations be-tween intermodulation and audiometric performance. However,recent evidence qualifies these correlations by suggesting that,instead of amounting to a sort of ”objective” audiometry, OAE dis-tortion measurements probe lower levels of OHC function. Theymay exhibit tuning of their own, and their integrity is necessarybut not sufficient for the OHC loop to be efficient. It may thus bepossible to use OAE distortion for splitting the cochlear loop intoconsecutive steps and probing them separately.

Paper SessionsMo. 14:30 Schweitzer Car acoustics I

Automatic Optimization of Acoustic TrimsVolker Schulz, Heiko AndräFraunhofer Institut für Techno- und WirtschaftsmathematikBy its ongoing improvement the simulation of car acousticsreached the edge to be fully integrated at the design and pro-totyping stage. The acoustic properties of the materials thereforeare becoming more and more important in the material selectionprocess. This selection can be done efficiently by the aid of soft-ware tools based on mathematical optimization strategies. Here,we present a software tool which extends the standard SEA soft-ware (AutoSEA) in order to find the optimal material propertiesreaching a desired sound pressure level automatically. The toolalso includes a database where measured and simulated mate-rial data can be stored. Our software tool has been developed forthe optimization of a headliner consisting of PET fiber material.Additional measurements showed that the acoustic properties ofthe investigated material follow the standard model of Delany andBazley. The developed optimization provides the flexibility in or-der to be used for the optimization of other parts of the interiorand materials such as foams or layered structures.

Mo. 14:50 Schweitzer Car acoustics I

Sound Radiation of a Gear Box Using Acoustic TransferFunctionsOtto Von Estorff, Marian Markiewicz, Ralf May, Olgierd ZaleskiNovicos GmbHMeasurement techniques combined with numerical methods canbe seen as an important step towards an acceleration of the de-velopment cycle of vehicles. In particular, by such combinations it


is possible to investigate the future performance of a system andto cor-rect weaknesses in a very early design stage. This paperpresents an example for the integrated usage of measurementsand simulation techniques in order to improve the sound radia-tion of a gear box. Although the focus is placed on the numericalprocedure, the essential input gained by related measurementswill be discussed as well. An advanced BEM formulation, rapidre-meshing tools and newly developed Acoustic Transfer Func-tions (ATF) are used to improve the acoustic behavior of the gearbox. It will be shown that the ATFs provide a very efficient wayto compute the sound radiation behavior of a vibrating systemwhen several design alternatives need to be investigated. More-over, the ATF concept will be employed to access directly thoseparts of the gear box which are responsible for certain maxima ofthe sound pressure level.


Influence of hoses on the sound field of engine compart-mentsTobias Kellert, Daniel SteinbacherInstitute of Technical AcousticsDuring the development of new vehicles one cannot underesti-mate the value of simulations. The goal of the BTPA/BTPS (bin-aural transfer path analysis/synthesis) is the evaluation of con-structive changes of the powertrain in early stages of develop-ment and their influence on the interior soundfield. For this pur-pose it would be desirable that all the acoustic and vibro-acoustictransfer paths from the source to the passenger’s ears are known.To accomplish this task, the airborne sound radiation of vibratingpanels in engine test benches can be measured, as well as sim-ulated with the help of finite element models. The sound radia-tion of engines was already analysed in the literature, but somequestions about the influence of the engine compartment still re-main. For the exact simulation of sound fields, the correct de-scription of the boundary conditions is of major importance. Al-though the characterisation of the behaviour of the surfaces iswell known, the consideration of fluid-filled hoses is not fully un-derstood. In this work, an experimental analysis was made in abuilt 1:2-model of an engine compartement and the influence ofthe hoses was analysed. The experimental data was then usedas basis for simulations with a finite element model of the en-gine compartment. In this presentation the comparison betweenmeassurements and simuations will be presented and the resultsdiscussed.



Use of One Dimensional Gas Dynamic Simulation to Predict”Rasping Noise” in ICE Exhaust SystemsMondher Ayadi, Robert MaunderRicardo Consulting Engineers LtdThe tone of a noise at the exhaust tail pipe can markedly affectthe sound quality inside vehicles. ”Rasping Noise” perceived asa metallic and strident tone and characterised by high frequencycomponents in the exhaust orifice noise, can have an adverse ef-fect on the vehicle marketability. A study on the generation mech-anism, providing an understanding, of this phenomenon high-lighted an acoustical non-linear behaviour due to coupling be-tween resonant modes within the exhaust ducts. WAVE, used topredict performance and noise in vehicle powertrains, providesa one-dimensional non-linear gas computation of gas dynamicbehaviour within the intake and exhaust systems. This paperpresents the results of a predictive rasping noise computationusing this one dimensional dynamic simulation approach. Thishas been carried out through a critical example of powertrain andexhaust system where rasping noise generation conditions havebeen experienced.


Validations on the acoustic behavior of a passenger car cav-ity by FE SimulationsDietmar Jennewein, Oliver Eichelhard, Harald FlötkeAdam Opel AGThe FE modelling of the acoustic behavior of a passenger carcavity was validated. Therefor, acoustic transfer functions fromseveral loudspeakers to a grid of multiple microphones inside acar were measured for different boundary conditions. First allthe interior components were removed from a production vehicle.Next single components like seats and interior trimm parts wereadded. The differences of the measured transfer functions werecompared versus FE simulations of corresponded modells. Thislead to informations how to modell the acoustic behavior of suchcomponents.



Efficient Sound Package Design Using Statistical EnergyAnalysis with Optimisation Through Genetic AlgorithmJean-Charles Bonnet, Javier Rodriguez-AhlquistRieter Automotive Management AGDetermining the best possible Vehicle Sound Package Designfor a set of different acoustic loads is a delicate exercise of bal-ance. Statistical Energy Analysis (SEA) has already proven to bea valuable tool for predicting whole-vehicle acoustic performanceat medium and high frequencies. By combining efficient SEAmodelling practices together with specially adapted optimisationalgorithms, overall lead-times can be substantially reduced, as-sisting decision-making earlier in the acoustic development pro-cess.


Prediction of Vehicle Interior Noise in High Frequency Rangeusing Statistical Energy Analysis Hybrid MethodIrena Hauer, Karoly Jalics, Hans Herwig Priebsch, Thorsten Bar-toschAkustikkompetenzzentrumThe application of Statistical Energy Analysis (SEA) in the de-velopment process of Vehicles has been intensified during thelast years. On one hand, experimental SEA is applyed to in-vestigate improvements of existing design. On the other hand,simulation models of vehicle ensembles and entire vehicles areanalysed by means of random properties of a network of cou-pled subsystems in the high frequency range. However, predic-tive analyses still require specific experience to extrapolate SEAmodels of new desing out of existing ones. The specific problemis the efficient and precise adaption of transmission loss factors,as usually, a support by experimental SEA is not possible. Toavoid these problems, the Hybrid Approach of SEA can be intro-duced. FEM models of all parts are used to simulate the SEAtests and provide internal and coupling loss factors to be used inSEA simulation models as a result. The paper describes the pro-cedure applyed for Hybrid SEA. An example of interior noise pre-diction for a passenger car in the frequency range above 500 Hzis given. Specifically, the validation of the Finite Element Modelrequired for high frequency range is discussed and the validationof the SEA Hybrid model is presented. Finally, the benefits ofthe methoddology compared to the common SEA approch areshown.



Structure-borne Sound in Automotive Structures: High Fre-quency Boundary Element Method (HFBEM) vs. StatisticalEnergy Analysis (SEA)Björn Knöfel, Ennes SarradjInstitut für Akustik und SprachkommunikationAt high frequencies, sound radiation and vibration transmissionare increasingly difficult to predict. The well known Statistical En-ergy Analysis has been for years more or less the only methodwhich could be applied for high frequency predictions with a sat-isfying result. Because of several reasons, it comes with somelimitations which are trying to be overcome by some alternativeapproaches. One out of these approaches, the High FrequencyBoundary Element Method (HFBEM) is being tested for its gen-eral usability in comparison with measurements on three differenttypical automotive structures (ripped plate, railway carriage, floorpanel of a Van). First HFBEM results will be presented and com-pared to SEA as well as measurement results.


Transmission acoustics in the overall automobile systemTobias Vöhringer, Axel MorsZF Friedrichshafen AG’If audible at all, the audibility of a transmission inside the vehiclemust not be disturbing!’ On account of this development goal, theacoustics engineers of transmission suppliers and vehicle man-ufacturers are again and again faced with new challenges. ZFFriedrichshafen AG, an independent transmission producer, isrepresented in a variety of vehicles of various vehicle manufac-turers with largely similar transmission types, which is due to thecompany’s modular system. Invariably, acoustical optimization inand on the transmission is carried out in the initial stage of de-velopment work. Often, the development goal mentioned aboveneeds to be pursued simultaneously for the most diverse installa-tion conditions. At the department for acoustics engineering of ZFFriedrichshafen AG, such necessity gave rise to an efficient tool,which allows the acoustically effective system environment of atransmission to be determined as a vehicle-characteristic vari-able: airborne-sound sensitivity (LSE). The process involves in-vestigation of the acoustic ’quality’ of the automotive body, start-ing from the interfaces of the drive train and including the pas-senger compartment. With regard to many noise phenomena,an essential share of noise can be attributed to noise transmis-sion. If, for example, gearing excitation on the transmission endis present across a broad operating-speed range, then audibility


within only narrow speed ranges is due to body-related structuralresonance. For the overall system to be optimized in ever shorterdevelopment cycles, suppliers and vehicle manufacturers have tocooperate on a very close and trusting basis.Getriebe


Microphone Array Measurements of Sound Radiation fromCarsAnders NordborgNordborg Acoustics ABTraffic noise is the most serious noise source. Although we al-ready know that the noise is generated by tyres, wind, exhaust,and engine, we still do not know exactly when a ceratain sourceis dominating. Therefore, we also lack certain information abouthow we should control traffic noise, to achieve maximum benefit.A series of microphone array measurements of noise from cars,fitted with different tyres, passing by at different speeds, revealfor instance when tyre noise is the dominating source, and is theone which should be controlled.


Analysis of passed by noise by Near Fielf Acoustic Hologra-phy (NAH)Randolf Arndt, Walter FließerAkustikkompetenzzentrumThe Near Field Acoustic holography (NAH) is a method for ana-lyzing noise sources. In acoustic holography the amplitude andthe phase of the sound pressure at one plane in the near field of asound radiating object has to be measured (here: car). This canbe realised by scanning the plane at stationary object conditionsusing one or more microphones (totally: about 800 microphonpositions). The method is based upon a two dimensional spa-tial Fast Fourier transformation of the measured pressure distri-bution at fixed temporal frequencies. The superposition of thewaves in the new plane is done by an inverse two dimensionalFourier transformation and results in a sound pressure distribu-tion in a plane parallel to the measurement plane. Applying thismethod for a series of parallel planes a three dimensional infor-mation of sound pressure and of sound intensity can be achieved.At the conditions of the highest passed by noise the NAH mea-surements were made at stationary conditions in the Near Field.From this plane the radiated noise will be caclulated at differ-ent planes far away from the structure. During these measure-ments reference microphones were placed close to the differentnoise sources and another reference microphone is 7,50 meters


away at the passed by measurement position. Correlation mea-surements between the reference points and the measurementpoints. The result is a distribution of the different noise sourcesin the different planes and especially at the measurement pointof the passed by noise.


Simulated Pass-By in Small Rooms Using Noise SynthesisTechnologySandro Guidati, Roland Sottek, Klaus GenuitHEAD acoustics GmbHPass-by measurements are a standard test procedure for everynew vehicle. The test is performed on a test track with a singlemicrophone at a distance d=7.5 m. Since there are only a fewtest tracks and the measurements depend on the ambient con-ditions, an indoor test procedure has been developed at HEADacoustics. Here the vehicle is placed on a chassis dynamome-ter. The noise is measured with a linear microphone array atd=7.5 m. A binaural time signal of a simulated pass-by measure-ment is generated by switching between the microphone signalsand applying filtering and smoothing algorithms. This procedurecannot easily be adapted for small rooms (d<7.5 m). For thispurpose HEAD acoustics has developed a new test procedurebased on results of the European research project SVEN. Micro-phones are placed close to the dominant noise sources of thevehicle. The airborne transfer functions between the source mi-crophones and observer positions in a plane at a distance of 4m are measured reciprocally. The vehicle noise produced on achassis dynamometer is subsequently measured with the sourcemicrophones. A simulation of a binaural time signal measuredat an arbitrary position is synthesized by filtering the source mi-crophone signals with the transfer functions and adding the re-sulting time signals. In this paper first results of vehicle noisemeasurements on the new HEAD acoustics four-wheel chassisdynamometer and corresponding simulations will be presented.The described technique can also be used to investigate the con-tribution of single sources to the exterior noise supporting thesound design process.

Mo. 14:30 Schuman Room acoustics: simulation, . . . I

Medea technique and Sound Systems in ChurchesErnst-Joachim Völker, Wolfgang TeuberInstitut für Akustik und BauphysikThe paper will deal with the medea technique in churches. Videotransmission with access to internet, recordings of services or


of a special speech are increasingly required. Microphone tech-nique and sound reinforcement must be of a high standard to ob-tain a better intellegibility of words for the congregation presentin the church and for the listeners at home, in hospitals or in oldpeople’s homes. The installations depend on different activitiesin the church, when e.g. the choir and soloists are singing, when6 microphones are required near the altar, additionaly wirelessmicrophones, when services or processions take place in otherparts auf the church, when a brass group is playing or a gospelchoir would like to perform on one side of the church. The au-dio und video equitment will be described including the routing ofsignals, recordings and both life transmission and post produc-tion for videos. The access to internet is included.


Quadratic Residue Diffusors Scale Model MesurementsPhilippe Woloszyn, Guillaume Rezeau, Bruno SunerCNRS UMR 1563This experimental study presents a scale model measurementsystem destined to allow concert hall acoustical design qual-ification. The research work aims to validate a mesurementprocedure with verifying the adequation between the theoriticalQuadratic Residue Diffusors interference model and its diffusionangular measurement on a 1/10 scale model. Defined for a fre-quency band from 1000Hz to 40kHz, the mesurement proce-dure takes place in a semi-anechoic room, exploiting an MLSsignal through time windowing. At every 2.5 degree incrementa-tion step, a 180 degree polar reference measure has been doneon a flat panel in front of the diffusor, before measuring the dif-fusor itself. Specular and diffuse reflexion modes comparisonbetween the scale model and the reference model (Helmholtz -Kirchhoff equation for infinitely rigid flat panel and boundary el-ements method for the Quadratic Residue Diffusor) confirms thesharp correlation between scale model measurements and thereference model, except for grazing angles directivity lobes qual-ification. Generalisation of those results will allow this method todescribe the diffusive behaviour of any surface, under the condi-tions of geometrical continuity for its contributing part.


Relevance and treatment of the low frequency domain inroom acousticsHelmut Fuchs, Frank Zickmantel, Constanze RauFraunhofer Institut BauphysikNoise in schools, open-plan offices and other communicationareas is predomi-nantly self-generated by the respective users.


The lack of sound absorption in traditionally furnished class-rooms or modern office environments forces all oc-cupants toraise their voices, as soon as the necessary communicationsamong them and on the phone sets in. Conventional dampingat mid- and high-frequencies by absorptive ceilings, carpets, cur-tains, claddings, sails and furni-ture may reduce the detrimen-tal effect of the room on speech intelligibility and the resultingnoise amplification. Current research and consultant activities atIBP have revealed, however, that novel low-frequency and broad-band absorber modules can tackle the problem more efficientlyat its roots. Examples show surprising improvements of acous-tic comfort in rooms where mid- and high-frequency absorptionmeasures had failed or were impracticable for one reason or an-other.


Loudspeaker positioning in rectangular roomsJean-Dominique Polack, Benoît Isabey, Pierre Leroyc/o Laboratoire d’Acoustique MusicaleThe field radiated by a loudspeaker is sensitive to the loud-speaker placement, especially at low frequencies, because theroom exerts an acoustical load on the membrane. For rectangu-lar rooms, the image source theory is used to simulate the load,because it takes phases into account. A proper classification ofimage sources makes it possible to use their lattice distribution tospeed up computation by means of perturbation theory. It buildsup the coherent part of the point transfer function - or acousticalload - from the lattice of image sources for different source posi-tions and the ratios give the compensation filters. Compared tomeasurements, the same overall shapes are obtained when pointsources are considered. Present developments include takinginto account the finite size of the loudspeaker, but not the phaseshifts at the reflections on the walls yet.


Microphone Array for SoloistsFrédéric BongardEcole Polytechnique Fédérale de LausanneA two-dimensional microphone array intended for recordingsoloists in a very reverberant cathedral is presented. This ar-ray belongs to an electro-acoustical assistance system which im-proves the hearing comfort in the cathedral of Lausanne duringchoral music concerts. For this particular application, constraintsare as follows : a) the array has to be placed quite far from thesingers (about 4 m), so its directivity index must be high enoughin order to reject the reverberated field ; b) the position of the


singers is not fixed but depends on the musical work, so it mustbe possible to electronically steer the main lobe. The use of afull two-dimensional array (squaring of microphones) leads to anexcessive number of microphones, which is why more reducedgeometries have been studied. A cross-shape has finally beenretained, i.e. two linear arrays at right angles to each other. Thedesigned array includes 15 hypercardioid microphones arrangedon a cross of 2m40 x 1m24 and a digital processing unit (DSP)allowing the implementation of FIR filters. By modifying the prop-erties of these filters, the main lobe can be steered in various di-rections. The directivity index is about 13 dB and the half powerbeam width varies between 25◦ and 55◦ according to the sectionconsidered in the directivity pattern. The nested subarray methodmade it possible to keep these performances roughly constantover a decade frequency bandwidth (300 Hz to 3 kHz).


Computerised planning aid for the design of anechoic cham-bersGerhard Babuke, Xiaoru Zhou, Xueqin ZhaFraunhofer Institut BauphysikA computer program using image sources was developed to aidthe design of anechoic rooms. The phase shifting caused by dif-ferent distances of all image and higher-order image sources andby reflection on each boundary surface are taken into consider-ation. The calculated sound pressure compares well with ”draw-away” measurements. Several parameters which influence thequality of an anechoic room can be investigated by means of thissimulation programme. It shows, that the absorption coefficient ofthe wall linings is by no means the only qualification requirementfor an anechoic room. Besides the absorption, the geometry ofthe room, location and size of the source, the orientation andlength of a prescribed measuring path and the respective testsignal all affect the acoustical quality of an anechoic room for agiven purpose.


Time reversal imaging of noise sources inside a reverberantroomGuillemette Ribay, Cedric Roux, Julien De Rosny, Mathias FinkESPCI - LOAIn a reverberant room, the multiple reflected echoes make imag-ing of acoustical random sources difficult. In this talk, we give anoriginal solution based on Time Reversal Principles. Basically, ina first step, the acoustic field due to a noise source is recorded


by a set of microphones. In a second step, all the recorded sig-nals are time-reversed and re-emitted by loudspeakers that nowreplace the microphones. We observe a strong enhancement ofthe mean intensity around the initial source position. In a firstpart, we highlight the formal link between time-reversal of pulsedand noise sources in reverberant media. Especially we deducethat the signal to noise ratio depends only on the number of pairsof microphone/loudspeaker for noise sources. Numerical simula-tions confirm these predictions. In a second part, we present ex-perimental results performed in a 5*3*3 m and strong reverberantroom. The intensity map of noise acoustic sources with a work-ing bandpass of [100 3000] Hz has been performed. The sameexperiment has been carried out with two coherent or incoherentsources. Moreover, the frequency dependence of the resolutionobtained with this technique is studied. Finally, we focus on theSNR with respect to the bandpass and central frequency.


A Four-Channel Dynamic Cross-Talk Cancellation SystemTobias Lentz, Christian RennerInstitute of Technical AcousticsTo reproduce a binaural signal using loudspeakers, a cross-talkcancellation system is needed. It is based on the transfer func-tions from each loudspeaker to each ear. To produce filters fora static cross-talk cancellation system, the four transfer functionsare measured with an artificial head. Afterwards the filter is cal-culated and used to cancel the cross-talk at the point the artificialhead was positioned during the measurement. The filter is validonly in this one point and this fact limits the systems applicabil-ity significantly. An adaptive cross-talk cancellation for a movinglistener requires a system being able to provide a valid filter-setfor each position. With the increase of the computation powerit is possible to calculate cross-talk cancellation filters online us-ing an HRTF-Database (Head Related Transfer Functions) and ahead tracking system to detect the listeners current position. Adynamic cross-talk cancellation system using two speakers is al-ready implemented (see DAGA 2002). Head rotation is possibleonly within the angle spanned by the loudspeakers. Aim of thiswork is to implement a dynamic four speaker cross-talk cancel-lation system to provide a full head rotation. Several approachesof filtering will be tested and compared.



Design of Loudspeaker Systems for Reverberant RoomsWolfgang Teuber, Ernst-Jo. VoelkerIAB Institut fuer Akustik und BauphysikImprovements of speech intelligibility in acoustic difficult roomswith long reverberation times (churches, concert halls) requirecarefully designed loudspeaker systems. To select adequatespeaker systems and their positions in the room acoustic crite-ria have to be taken into consideration such as sound absorb-ing areas, listener positions, parallel walls and reflections aswell as technical data of loudspeaker systems like frequency re-sponse, Q-factor etc. Calculations, computer simulations and re-sults of measurements are presented to show the influence ofloudspeaker characteristics to the direct / diffuse sound field andspeech intelligibility.


Room Acoustical Simulation at Low Frequencies Using theScattering Element Method (SEM)Matthias Blau, Andreas WildeInstitut H+A, FH Oldenburg/Ostfriesland/WilhelmshavenArguably all known room acoustical simulation packages assumegeometrical ’ray-like’ sound propagation and are thus limited tohigh frequencies and/or diffuse sound fields (large rooms). In thepresent work, a wave approach, the so-called scattering elementmethod (SEM), is used to predict room acoustical parameterssuch as RT, C80, G, Tc at low frequencies for 5 microphone posi-tions in a reverberation room (empty and with 4 plate absorbers).This situation is modeled by 1.) adding a uniform absorption toall boundary (wall) nodes, in order to adjust the reverberationtime to the expected statistical value for the empty room, and 2.)by discrete-time implementation of multiple-input-multiple-output(MIMO) reflection coefficient matrices representing the dynami-cal behavior of the plate absorbers. The simulation, performed in3rd octave bands, takes about 20 min on an ordinary PC; the pre-dicted values of the room acoustical parameters conincide withmeasured ones in an acceptable manner.



The extended model to simulate the Quetzal echo at theMayan pyramid of Kukulkan at Chichen Itza in MexicoNico Declercq, Joris Degrieck, Rudy Briers, Oswald LeroySoete Laboratory, Department of Mechanical Construction andProduction, Ghent UniversityIt is well known that a handclap in front of the staircase of thepyramid produces an echo that sounds similar to the chirp ofthe Quetzal bird. This phenomenon occurs due to diffraction.There exist some publications concerning this phenomenon andeven some first attempts are reported to simulate it. Recently, ithas been shown [Declercq et al, J. Acoust. Soc. Am. 113(4),2189, 2003] that it is possible to reproduce the echo by meansof a simulation which is based on the theory of the diffraction ofplane waves and which takes into account continuity conditions.The latter theory is the building block for a theory that tacklesthe diffraction of a spherical sound pulse. By means of theseprinciples it is possible to simulate the echo following a handclapin front of the staircase. This paper shows results obtained bymeans of an extension of this model where also reflections onthe ground in front of the staircase are taken into account. Theseresults correspond better to reality than the previous results.


Influence of the ears canals location on spherical headmodel for the individualized interaural time difference esti-mationSylvain Busson, Rozenn Nicol, Olivier WarusfelFrance Télécom R&DThe spatialization rendering with binaural synthesis is still lim-ited by the individualization of the spatial filters, which are usuallycomposed of a pure delay for the interaural time difference (ITD)and a minimum-phase filter for the spectral cues. This paperdeals with the individualization of the ITD based on physical mod-eling. Individualized ITDs are well predicted by a spherical-headmodel with a customized radius derived from an empiric linearcombination of three head anthropometric parameters describingthe listener’s head. However it can be observed that the constantITD contours computed from the spherical-head model are con-centric circles, whereas the constant ITD contours extracted frommeasured HRTFs show deviations from these circles, especiallyfor azimuths near to the interaural axis. The location of the earswith respect to the center of the head seems to be the main factorto reproduce these deviations. The authors propose to introduce


a parameter governing the ears’ shifting, so as to break the sym-metry of the spherical-head model. This idea leads to a newformula for the computation of individualized ITDs. The formulais tested by comparison with measured data. The authors alsoexamine to what extent the deviations of the measured ITD alongthe circles contribute to the individualization. Psycho-acousticalexperiments are performed to answer this question.

Mo. 14:30 Tivoli 1 Recent advances in speech . . .

An extension of PESQ for assessing the quality of speechdegraded by severe time clipping and linear frequency dis-tortionsJohn Beerends, Jeroen VugtTNO TelecomPESQ (ITU-T recommendation P.861) has been established as aworld standard for assessing speech quality. This paper shows itslimitations when it is used for assessing the quality of speech thathas been degraded by large amounts of time clipping and linearfrequency distortions. For both types of distortion an extension toPESQ has been developed. Two types of extensions were inves-tigated, using a separate indicator for quantifying distortions, andusing a modification of the PESQ algorithm without introducingseparate quality indicators. A significant improvement in corre-lation could be obtained with these types of distortions withoutdegrading the PESQ performance on other types of distortion.


P.SEAM, a Breakthrough in Single Ended Voice Quality Test-ingChristian SchmidmerOPTICOM Dipl.-Ing. M. Keyhl GmbHP.SEAM will be the new ITU recommendation for single ended(non-intrusive) voice quality testing. In Sep. 2003 the ITU-TSG12 finished the competitive phase with the selection of the finalcandidate for the recommendation. All four models which wereproposed during the competitive phase proved to be amazinglyaccurate. The performance was sometimes even better than theperformance of previous intrusive measures. The basic principleof P.SEAM is to first detect the dominant distortion by analyzingthe output of various distortion detectors. The results of thesedistortion detectors will then be weighted depending on the dom-inant distortion, thus leading to the final Mean Opinion Score asin indication of the listening quality. Some of these distortion de-tectors, being key to the success of P.SEAM will be presented indetail. Furthermore the performance of P.SEAM in various appli-cations will be examined.



Predicting speech quality under packet loss: Extension ofthe E-modelAlexander RaakeInstitut für Kommunikationsakustik (Web: www.rub.de/ika)Network planning models allow the quality of a network to bepredicted before it has been set up. The model currently rec-ommended by the ITU-T for this purpose is the so-called E-model. It was designed for the planning of traditional wireline,circuit-switched telephone networks. In today’s networks, how-ever, packet-based transmission techniques are typically applied.Packet-based transmission shows new types of impairments likepacket loss and jitter, which were not included in the original ver-sion of the E-model. In this paper, the extension of the E-modelto predicting speech quality under packet loss as one exampleof time-varying degradations is presented. Different aspects ofpacket loss distributions will be addressed: In the first part, a for-mula will be presented for quality prediction under random loss,which can be regarded as the simplest case of loss distributions.In a second step, the formula will be extended to the prediction ofburst loss, i.e. packet loss for which the loss of a particular packetdepends on whether or not the previous packet was lost. Duringone telephone conversation, the rate of lost packets may varyconsiderably also on a more macroscopic level, leading to longerperiods of very high and longer periods of very low quality. Bothlong-term variations and short-term variations will be addressedin this paper, and quantitative approaches will be suggested forthe prediction of speech quality in these cases.


Recent standardization work on non-intrusive evaluation ofvoice quality in IP environmentsVincent BarriacFrance Télécom R&DThis presentation begins with a short overview of the existingstandardisation bodies involved in this topic (definition of metricsand description of measurement methods) and the document al-ready issued by these bodies.. Then, the work of Q.16/12 ofthe ITU-T (whose rapporteur is making this presentation) is ad-dressed more in detail. In particular, we will address the update ofexisting ITU-T recommendation on INMDs (P.561 in 2002, P.562to come), to take into account new type of connection for themeasurement probes and new parameters related to transit on IPnetwork (most of them being taken from IETF RFCs). But mostof the presentation will be devoted to the on-going competition for


the selection of a future standard model for the evaluation of voicequality in VoIP services based on protocol information (known asP.VTQ, 2 candidates in competition), supposed to address a largevariety of network and terminal conditions. The concept, termsof reference, basic characteristics, advantages and limitations ofP.VTQ will be presented and discussed.


Supervision of perceived quality in VoIP telephony servicesJean-Yves Le SaoutFrance Télécom R&DThe supervision of the quality of new telephony services is a realchallenge for telecommunication operators. Currently, differentmethods and tools are used, whose advantages and drawbackswill be briefly discussed. As far as Voice over IP is concerned,the fact that packet and signal are processed by the terminalmakes it necessary to measure the end to end (from mouth toear) quality, not only network QoS, and thus to take into accountthe terminal behaviours. The installation of probes on the endpoint terminals allows such an evaluation and makes it possibleto apprehend the real quality perceived by the user by taking intoaccount other parameters than networks metrics such as jitteror packet loss ratio.. In this presentation, we will describe anoriginal operational solution to the problems of supervision of thequality of VoIP telephony services based on this concept. Thissolution is based on a soft probe installed on the VoIP terminalof the user (PC with soft phone or IPphone). During communica-tions, and without interfering or disturbing the conversation, sucha probe can determine parameters characterizing the perceivedquality, based on the analysis of the speech signal (e.g. : P.56,P.561, P.SEAM) or of the protocol (e.g. Y.1540, P.VTQ). At theend of each communication the probe uploads the measurementresults to a central server from where actions of supervision orcorrection can be performed.


Speech Quality ”Quick Check” for VoIP TerminalsFrank Kettler, Frank Rosenberger, Hans Wilhelm GierlichHEAD acoustics GmbHVoIP terminals need to be carefully designed in order to guar-antee a high speech quality for the user of this communicationscenario. Some of the parameters which have to be consideredare comparable to traditional telephonometry like frequency re-sponses, distortions or loudness ratings of the handset. Otherparameters have to be adjusted differently due to the IP specifictransmission characteristics. One example is the echo delay in IP


scenarios which may be significantly higher compared to the tra-ditional telephone network. Consequently the terminals need toprovide a higher echo attenuation expressed e.g. by the parame-ter terminal coupling loss (TCLw). Current standards like the TIA-810 require an echo attenuation of 55 dB instead of 46 dB whichis required for ISDN phones. A comparison test was carried outwith 5 different VoIP terminals (handsets). The most importantparameters were measured (”Quick Check”) and are discussedhere. These results demonstrate different implementation strate-gies of manufacturers and the current quality differences of VoIPterminals.


Speech Quality - a Multidimensional Problem: An Approachto Combine Different Quality ParametersHans Wilhelm Gierlich, Frank KettlerHEAD acoustics GmbHThe evaluation and/or prediction of speech quality in moderntelecommunication scenarios is getting increasingly complex.Due to a variety of non-linear and time variant signal process-ing in terminals as well as in networks the description of the per-ceived speech quality by a single number is a challenging topic.Established procedures like the E-model or the perceptual evalu-ation of speech quality (PESQ) are either not suitable for non-linear and time variant systems or describe just a part of theoverall speech quality. The presentation will give an overview ofthe different parameters influencing the speech quality in moderntelecommunications systems and their relationship. Approacheshow to combine the different values to a single number will bediscussed.


Comparative Speech Quality Evaluation of Mobile PhonesUsing Advanced Testing MethodsFrank Kettler, Frank Rosenberger, Hans Wilhelm GierlichHEAD acoustics GmbHThe complexity of signal processing implemented in mobilephones has grown continuously over the past years. Echo can-cellation, comfort noise injection, noise reduction or dynamiclevel controlling typically found in hands-free devices are now im-plemented in mobiles. Therefore the traditional testing methodsare no longer sufficient in order to reflect conversational speechquality. More complex testing is necessary. Conventional mea-surements like frequency responses can be made more realisticby using an artificial head equipped with a more realistic artificial


ear which shows the pressure force dependent acoustical leak-age comparable to the human ear. This measurement also guar-antees more realistic results when determining objective listeningquality scores (MOS-LQO according to ITU-T-RecommendationP.800.1). Furthermore the implemented signal processing sig-nificantly influences the double talk behavior and the quality ofbackground noise transmission. Consequently appropriate testsand analyses are necessary. This presentation introduces ad-vanced testing methods which offer a high efficiency in gaining acomplete picture of the conversational quality of a mobile phone.Comparative results of different mobiles are discussed.


Quality Prediction Models for Telephone-Based Spoken Dia-logue SystemsSebastian MöllerInstitut für Kommunikationsakustik (Web: www.rub.de/ika)The spoken interaction between a human user and an applica-tion based on speech technology (e.g. for information or trans-action tasks, like railway information or telephone banking) gainsground in modern telephone networks. In order to estimate theoverall quality a user of such a service will experience, qualityprediction models have been set up. They calculate an index re-lated to user satisfaction on the basis of parameters which can belogged during the interaction, either automatically or with the helpof an expert transcription. The most popular modelling approachis the PARADISE framework developed by Walker et al. at AT&T.In the talk, an overview is given about the modelling principles aswell as the prediction accuracy which can be reached for human-machine interaction (HMI). Starting from a taxonomy of qualityaspects which have demonstrated relevance for the HMI situa-tion, it is shown that the PARADISE approach is still very limitedboth with respect to the predicted quality indices as well as withrespect to the amount of subjective judgement variance coveredby the model. The correlation to subjective judgements is consid-erably lower than for speech transmission quality models. A newproposal for predicting individual quality aspects is made in orderto obtain more generic quality estimations.


STIPA - The Golden Mean Between Full STI and RASTIOle-Herman BjorNorsonic ASThe Speech Transfer Index (STI) as developed by TNO in Hol-land during the last thirty years, has proven to be one of the


most reliable objective indicators for speech intelligibility predic-tion. However, as the measurement time of a full STI requiresabout 15 minutes, it is often necessary to use an approximationto the STI-value, which may be measured in shorter time. Forthat purpose the Room Acoustics Speech Transmission Index(RASTI) was developed in 1979. Through its use, it has beennoted that unreliable indications in some situations as measure-ment of PA-systems may be obtained. A more reliable indica-tor STIPA, developed for measurement of PA-systems, has re-cently been standardized by IEC. This paper describes how themeasurement of STIPA may be implemented in a modern digitalsound level meter.

Mo. 14:30 Tivoli 2 Active control I

A course on active noise control held at the Technical Uni-versity of BerlinAndré JakobInstitut für Technische Akustik , Technische Universität BerlinDuring summer semester 2002 a course on active noise and vi-bration control was held at the Institute of Technical Acousticsof the Technical University of Berlin, and was repeated in wintersemester 2002/2003. The course was designed for students ofacoustics. It introduced the physical basics of active control aswell as the control strategies, i.e. feedforward, feedback, andthe adaptive digital filters, which are commonly used for con-trol. The presentation will give an overview of what was taughtthe students, keywords are: overview of state of the art, nec-essary degree of exactness of the secondary signal, HermitianQuadratic Form, one-dimensional ANC, ANC in free-fields, ANCin enclosures, AVC of a plate strip, ASAC of plate strip, manualcontrol, digital signal processing, transformations, digital filters,adaptive filters, LMS algorithm, system identification, filtered-xLMS algorithm, multiple error LMS algorithm, adaptive algorithmfor feedback control, digital signal processors (DSPs), case studyof active control of a double-glazed window. The analytical calcu-lations, performed for the students, were illustrated with computersimulations and animations. These will be shown in the presen-tation.



Causality Constraints in Multi-channel Active Control ofRandom NoiseEmmanuel FriotLMA CNRSActive noise control over large areas often requires large sets ofactuators and sensors. In the single-channel case and for ran-dom noise, the causality of active control can be easily checkedfrom the transducer locations; for example to stop low-frequencynoise propagation in a duct a detection sensor must be set up up-stream the secondary source. In the multi-channel case, causal-ity is more difficult to be enforced; in this paper it is indeed shownthat in some pathological cases optimal noise control can requirecontrol filters which include an infinite non-causal part, simplybecause of the multiplicity of error sensors. This may explain thedifficulties encountered when implementing random noise con-trol in large cavities. In other cases the single-channel resultgeneralizes: perfect feedforward control can be achieved if a ref-erence sensor detects the incoming noise with a time advancelarger than the overall delay in the longer secondary path be-tween a secondary source and an error sensor. In the paper sim-ple cases with two loudspeakers and two microphones in free-field are considered to derive these results; optimal non-causalcontrol is derived analytically while causally-constrained controlis approximated by Finite Impulse Response filtering computedvia a Filtered-reference Least Mean Square adaptive algorithm.Guidelines to prevent a loss of causality due to the multiplicity ofchannels are also given for more complex cases.


Active Noise Control Description by Using the Direct FiniteElement Method (DFEM)Gerhard Hübner, Max KrausUniversität StuttgartAs known, the DFEM is a very appropriate method to describethe sound power radiated by technical sound sources. The mainadvantage of this method is the short, direct way for calculatingthe main sound emission quantity (the sound power), by using thesource outer surface quantities (normal vibration components,its phase relationship and the belonging to geometrical quanti-ties) directly without calculating airborne sound field quantities(sound pressure, sound velocity, sound intensity) ”in between”.The method determines the totally radiated sound power by asum of partial sound powers individually generated by all singlemonopoles replacing the machine’s outer surface radiation andadditionally by the sum of all interaction sound powers generated


by the combination of all monopole pairs. Especially the effectof the monopole pairing gives the important contribution to thefinal sound radiation behaviour of the different types of sources,including the increasing and decreasing of the radiated soundpower. In so far the monopole pair may be regarded as the ”ele-mentary stone” for any active noise control description, too. Thepaper deals with the sound power effects of several combinationsof monopole systems different in amplitude and phase relation-ships and discusses the conditions for noise reduction in generaland especially regards questions of active noise control. This is-sue is a first step of an investigation to describe general principlesof active noise control by using the DFEM.


Considerations on the Realtime Realisation of a 2D-Feedforward-ANC-System Part 1: Aspects to the SoftwareDetlef Krahé, Mattias TrimpopUniversity of WuppertalThe algorithm presented in former papers realises the approachin the space-frequency domain by the FFT. This solution resultsin the disadvantage of a block-wise processing causing a longprocessing delay alone by collecting the data for each block. Soin addition with the time for other processing steps the maximumallowed delay of about 1 ms is exceeded. Therefore another so-lution is developed working directly in the time domain and avoid-ing the block-wise processing. This solution is presented anddiscussed.


Considerations on the Realtime Realisation of a 2D-Feedforward-ANC-System Part 2: Aspects to the HardwareMattias Trimpop, Detlef KrahéInstitut for noise controlAn experimental assembly for a 2D-feedforward-ANC-systemcontaining 24 microphones and 12 loudspeakers should be pre-pared for real time processing. Up to now experiments were donein an off-line-modus. This means a stimulated source (primarysource) was recorded, the signals were processed off-line andthen the fields of the secondary sources driven by the processedsignals and the primary source are generated simultaneouslyand superposed. The on-line-modus (realtime) requires specialconditiones for the hardware as well as for the software. Theseare a small processing delay by the several components (e.g.ADC and DAC) and a sufficient signal processing power neededto realise 24x12=288 transfer functions. This paper presents amultiprocessor system that can fulfill the needed specifications.



Improved shielding effect of noise screens by means of ac-tively controlled headpiecesHyo-In Koh, Michael MöserInstitut für Technische Akustik , Technische Universität BerlinOn the basis of theoretical studies on the effect of the cylin-ders attached to acoustical screens, a numerical study of ac-tively controlled headpieces of noise screens has been presentedlast year. According to the theoretical investigations the tangen-tial sound power-transport parallel to the surface of the attachedcylinder is crucial in the shielding effect. In the last numericalstudy, the surface impedance of the headpiece was actively con-trolled to minimize the power transport along the headpiece asmuch as possible, i.e. the sound field on the surface was lo-cally minimized. The calculation on the basis of a two dimen-sional model showed that a deflection of the incident sound waspossible by means of a secondary sound field. The acousticalshadow region was more pronounced in both near- and far-fieldcompared to the passive case with rigid surface. For a relativelywide frequency range it was also possible to find optimal posi-tions for the secondary sources and for the error microphones.In the present study the system was investigated experimentally.The physical principle from the theoretical study could be realizedpractically by means of active control. The optimal configurations,which were found in the numerical analysis were also proven tobe effective in the experiment.


Active control of sound travelling through a bogie-shrouds-barriers-combinationCarsten Spehr, Michael MöserInstitut für Technische Akustik , Technische Universität BerlinThe combination of bogie shrouds and small barriers is promis-ing method in the abatement of railway noise. In order to re-duce the noise transmission through the gap between the bogieshroud (on the train) and the small barrier the gap should be assmall as possible. However, for security raisons the Bahn AGdefined a minimum distance between bogie and shroud, throughthis the noise travels unhindered and limits the noise reductionof the method. The aim of this project is to develop a method toactive reduction of the sound travelling through the bogie shroud-barrier interspace. A brief introduction in the theoretical work willbe given, with the main focus at the following points. · The soundpropagation from the primary source through the shroud-barrier


interspace in order to determine the possibilities for an improve-ment of the insertion loss. Shroud and barrier are modelled asoverlapping cylinder segments (two-dimensional) to examine theeffects of different positions of the bogie and the barrier as wellas of the acoustic sources. · In the second part we consider anactive feedback system. Thus the influence of a finite impedanceat the secondary loudspeaker (with mass-, spring-, or absorptioncharacteristic) or a deviation from the ideal transfer function onthe insertion losses with active control could be examined. · Inorder to examine the possibilities from two independent feedbackloops too, the model was extended by a further secondary loud-speaker. Based on this a test rig was developed. Results of thiswill be presented.


Control of low frequency enclosed, harmonic sound fieldswith active absorbersStefan Zimmermann, Phil Joseph, Philip LeistnerPrivatThis paper describes an active absorber for the control of lowfrequency enclosed, harmonic sound fields. The active absorberconsists of a microphone located immediately adjacent to a loud-speaker. The microphone signal is used to drive the loudspeakervia a high-gain inverting power amplifier thereby causing thepressure at the microphone to be driven close to zero. By anal-ogy with passive absorbers, the behaviour of the active absorberis completely described by its input impedance. It is shown thata single active absorber can produce significant reductions in thetotal acoustic potential energy of the sound field at low frequen-cies when correctly positioned in a rigid room. The relationshipbetween absorbed sound power and the feedback gain of theactive absorber is derived, and hence a criterion is establishedfor the optimal gain that maximises sound power absorption.The use of multiple active absorbers is also investigated. It isshown that mutual interaction between active absorbers, but alsothe presence of passive absorption greatly affect control perfor-mance. Further significant reductions in total acoustic potentialenergy in the room are obtained by increasing the total numberof active absorbers uniformly distributed over one surface of theroom. Above a critical number of absorbers, however, the effec-tiveness per unit absorber begins to decrease. Measurementsof the total acoustic potential energy before and after control arepresented for four and nine active absorbers, for varying amountsof passive absorption treatment in the room. The results areshown to match predictions in reasonable limits.



Reduction of sound immission in buildings by sound insula-tion using active facadesLothar Kurtze, Torsten Back, Rainer NordmannDepartment of Mechatronics and Machine Acoustics, DarmstadtUniversity of TechnologyLow sound immissions into rooms have become more and moreimportant for the construction of large buildings such as hotels,hospitals, or conference centres. Particularly near airports, majorroads, or railway lines, the acoustic shielding of ambient noise is,in many cases, difficult to handle with classical passive methods.The reasons lie mainly in the physical and financial limitations ofthe construction. In modern architecture, facades serve as theouter skin of a building and so have to fulfil the demand of staticstrength. However, if facades are planned in a suitable way, theycan act as a barrier for incident sound fields (for example by theuse of active noise control). The investigation of the possibilitiesfor a reduction of structure borne sound using active techniquesis the object of a research project initiated by the German Ministryof Education and Research. One of the central questions so faraddressed by the project is the investigation and the experimen-tal detection of the lower natural frequencies and eigenmodes ona reference facade composed of several frame elements. Themode shapes were then compared with the results of numericalFEM calculation. The next step is to find an actuator design forgenerating anti-vibrations. After that, suitable positions for the ac-tuators and an appropriate control system must be determined.At the conference, the results of the first year of research willbe presented. This will include a report on the experiment con-ducted at the facade test facility and the calculations to determinethe natural frequencies and the mode shapes of the reference fa-cade.


Are electromagnetic Receivers suitable for ANR Earplugs?Karl Buck, Véronique Zimpfer-Jost, Armand Dancer, PascalHamery, Philippe HerzogI.S.L. : Institut franco-allemand de Recherche de Saint LouisCrew members working close to modern fighter aircraft are ex-posed to very high level continuous noise in the mid-frequencyrange. Presently available hearing protectors cannot cope withsuch high levels. A possible improvement would be an ANRearplug with an effective bandwidth extended to frequenciesexceeding 1 kHz. Taking into account the dimensions thatare involved, and the bandwidth of the transducers, this goalshould not be impossible to obtain. However, measurements


of electro-acoustical transfer functions of configurations usingelectro-magnetic (hearing-aid type) receivers seem to show a de-lay of about 20 µs added to the ”minimal” phase behaviour. Outof these 20 µs, only a maximum of 6 µs could be accounted forthe distance between the receiver’s membrane and the micro-phone. The paper presents different approaches that were usedin order to determine the source of the unexplained 15 µs. It alsoexplains the difficulty to decide whether we are confronted to adelay or whether the effect is due to the phase shift of some ”hid-den” pole. It also presents the performance of ANR earplugs us-ing digital filtering, and the difference in efficiency of an (close toideal) ANR system when using two different transducer technolo-gies: electro-magnetic (hearing aid type), or reversed condensermicrophones (B&K 1/4”).


A preliminary study of an isodynamic transducer for use asactive acoustic materialsHervé Lissek, Xavier MeynialEcole Polytechnique Fédérale de LausanneActive control of the acoustic impedance of walls in rooms allowsfine control of reverberation in auditoria. Such active materialsmay use locally reacting cells comprising a transducer connectedto an electronic control circuit. The feedback circuit is based ona linear combination of the pressure at the transducer diaphragmand its velocity, and allows making the active material absorbing(absorption coefficient alpha close to 1), but also reflecting (al-pha close to 0), and even ’super-reflecting’ (alpha<0 !). Most ofthe characteristics of an ideal transducer for use as active ma-terial seem to be reached by isodynamic transducers, for theiracoustical performances as well as for manufacturing costs con-siderations. We present results from simulations involving a fi-nite element model of such a transducer, which predict a goodcontrol over two frequency decades. Preliminary experimentalresults obtained with a basic prototype of isodynamic transducerare encouraging. It is likely that better results can be obtained(especially in the ’super-reflecting’ case) with closer control overthe various mechanical parameters. Future work will also ad-dress the optimisation of the magnet geometry and the assemblyof the diaphragm.



Design of a dedicated PVDF microphone for active noisecontrol in high levels environmentHervé LissekEcole Polytechnique Fédérale de LausanneWith the aim of lowering noise disturbances within high soundpressure levels environments, active strategies have been de-veloped. Specifications for a dedicated microphone have beendrawn, with respect to the acoustical signature and the levels ofthe noise source. The investigations on a dedicated transducer,able to reach the compliance specifications as well as to supportthe noise levels generated by the source without distortion, led todevelop a PVDF-based microphone, compliant with the extremeenvironmental conditions. We present the technological solutionsconsidered to reach the acoustical specifications, on the basis ofan electroacoustical model used for numeric simulations in a firstpart, and then show experimental results obtained with a proto-type. We then conclude with the perspectives provided by thiskind of transducer used within rough sound fields.

Mo. 14:30 Gutenberg Musical acoustics

Influence of decorations on the sound of church bellsJochen Bauer, Lothar Schmidt, Benno Kotterbamd-pro GmbHThe first casted bells for the Dresdner Frauenkirche had a dis-cord. Particularly the beat of the prime caused that six of theseven bells didn’t pass the sound test. So a further casting hadto be done. Experts agreed that the decorations had causedthe problem. But they didn’t agree which part of the decorationhad the biggest influence on the affected sound components. Bysimulating a bell model with variations of decoration the causeof the beat was identified. By accompanying measurements ofthe real bells the transferability of simulation results to real bellswas proved. The disturbing acoustic effects of simulation and realbells did comply. The use of simulation for bell development is ev-ident. The harmony of the bell sound can be predicted and alsothe risk of discording bell sounds caused by decorations can beestimated. Variations of bell models allow optimizing the soundwithout producing prototypes. Optimization and development ofnew splines are accelerated.



Acoustic analysis of sonority and discord of church bellsLothar Schmidt, Jochen Bauer, Benno Kotterbamd-pro GmbHThe sound of bells enchants us. By faulty manufacture and dis-advantageous figuration of decorations a discord can be caused.Ageing and cracks initiation affect the sound. The metrologicalanalysis of the bell sound is used to document the result of thebell casting process. Continuous control measurements allowdetecting changes in material and bell structure precociously. Byanalysing the time domain behaviour of the bells single tones amusical fingerprint can be generated. It comprises the measuredharmony, the maximum sound level, attach and decay as well asthe beat of single bell tones. The approach to the musical finger-print is demonstrated with one bell for the Dresdner Frauenkirche.Because the first casting result wasn’t accepted because of a dis-cord and the second casting result was accepted, we can com-pare two bells of the same spline. One with a discord and onewith a good sound. The differences of the fingerprint data helpus to identify the cause of the discord. Together with simula-tion results or modal analysis the fingerprint enables us to locatecauses of discords or longtime changing effects. These methodscan also be used for product testing in industrial production en-vironments. The use of acoustic resonance analysis for producttesting is well established in many applications.


Monopole Breathing of the Organ Pipe BodySteffen BergweilerAPKM, Physik, Universität PotsdamUsing a new sensor method we investigated the organ pipesbody. The area of investigation was the oscillation of the pipe res-onators cross-section. We found that, additionally to quadrupoleoscillation, it also shows a monopole oscillation. The results arebased on measurements of four groups of nominally equal pipes.They differ in two properties: the choice of material and the profileof the tube resonators wall. A total number of 40 pipes being in-vestigated, make the obtained results statistically very safe. Theresults are discussed with respect to the relationship betweenair-column and pipe-body oscillations. Differences due to the in-fluence of material and the resonators wall profile will also beconsidered.



An experimental study of the acoustic radiation of a concertharp using Nearfield Acoustic HolographyNicolas Dauchez, Jean-Hugh Thomas, François Gautier, Jean-Claude PascalLAUMPlanar Nearfield Acoustic Holography (NAH) [1] is used to pro-vide acoustic features of the radiation of a concert harp [2]. Theacoustic pressure fields are measured from two planes in thenearfield of the soundboard and the soundbox holes while a sta-tionary mechanical excitation is placed at one string location.NAH provides a reconstruction of the pressure field and the nor-mal velocity on the source planes by solving an inverse problem.Acoustic intensity vectors are computed from the measurements.A detailed description of the acoustic intensity field radiated bythe sounboard surface and the soundbox holes is performed.Calculations of acoustic power radiated by the two sources al-low us to quantify their relative importance. In three frequencyranges, it is shown that soundbox holes radiate more than thesoundboard. In the first range, it is suggested that the acousticradiation of the instrument can be described by two monopolesimplying that in this range the harp acts as an equivalent elasticHelmholtz resonator. [1] J. D. Maynard, E.G. Williams and Y.Lee,Nearfield Acoustic Holography: I. Theory of generalized holog-raphy and the development of NAH, J. Acoust. Soc. Amer. 78,1395-1413 (1985) [2] F. Gautier, N. Dauchez, Acoustic intensitymeasurement of the sound field radiated by a concert harp, sub-mitted to Applied Acoustics, (2003)


Noise Control and Professional Musicians - 87 dB(A) Expo-sure Level LimitGeorg BrocktBundesanstalt für Arbeitsschutz und ArbeitsmedizinThe EU-Directive 2003/10/EC on the requirements of health andsecurity of workers to the risks arising from physical agents(noise) demands the adherence of a limit value for the weeklynoise exposure level of 87 dB(A) for all employees, taking intoaccount the attenuation of hearing protectors. Professional mu-sicians and employees in entertainment industry are explicitlystated within the Directive. In the case of musicians, there appearsubstantial difficulties on the conversion of this Directive. A noisereduction at the source is hardly possible, while carrying hear-ing protection can affect the making of music or even prevent itat all. However, the average sound pressure levels in orchestras


are in the range of 80-100 dB(A). Options of noise control for mu-sicians are means of employment organization, room acousticalimprovements and the reasonable application of hearing protec-tion. But obviously no simple general solution exists, which limitsthe sound exposure without affecting the artistic liberty. This con-tribution gives a survey on the requirements of the EU-Directive,typical sound exposures and potential noise control measures fororchestras.


Acoustic impedance measurement of the clarinet play-ers’airwayClaudia Fritz, Joe WolfeIRCAMUnderstanding of the playing regimes of the clarinet requiresmeasurements of the acoustical impedance spectra of theplayer’s airway, as well as that of the instrument and knowledgeof the mechanics of the reed. Previous measurements of theairway (Hoekje, Wilson) are not fully exploitable or applicable be-cause they either were not necessarily performed in playing con-ditions, lack phase information, or contain high levels of back-ground noise. We report experiments to measure the impedancefor conditions close to those used in playing. The impedancespectrometer used, originally developed by Smith and Wolfe, hasbeen modified by the integration of the measurement head ina clarinet mouthpiece. A highly damped parallel leak, with lowacoustic admittance, enables the musicians to blow air into the’instrument’. Mounted on a tube with appropriately placed ringsunder the fingers, this convincingly simulates, for the player, thefeeling of holding a clarinet ready to play. Impedance spectra(magnitude and phase) were measured for a range of simulatedplaying conditions with a group of professional clarinettists. Thereproducibility of the measurements is high, probably becauseaccomplished musicians have a ’muscle memory’ that enablesthem to reproduce with high precision the vocal tract and tongueconfigurations required for particular playing conditions. The sig-nificance of these spectra will be discussed in terms of modelsof the playing regimes of clarinets, and also in terms of play-ers’statements about the role of the vocal tract in different regis-ters and conditions, and their intentions when preparing to play.



Spectral sources of basic perceptual dimensions of violintimbreJan StepanekAcademy of Performing Arts in PragueDissimilarity in timbre was assessed in five sets of violin tones(pitch B3, F#4, C5, G5, D6) by twenty experienced listeners - vi-olin players. The results of five listening tests (individual dissimi-larity matrices) were separately processed using latent class ap-proach (CLASCAL). This approach yielded to perceptual spacesof common dimensions shared with all listeners and in each stud-ied pitch to the division of listeners into two classes. Classesof listeners were clarified by exclusion of outstanding listeners.Perceptual spaces of groups (clarified classes) exhibit more sta-ble dimensions. Moreover, the second group (with significantlyhigher dissimilarities) has optimal model of higher dimensionalityin pitches B3, F#4 and C5. Spectral sources of individual dimen-sions for both groups were calculated and compared. The first di-mension is significantly correlated with spectral centre of gravity(positively), with levels of high frequency harmonics (positively),and with the level of the first harmonic (negatively) for pitchesB3 (in both listener groups), F#4 (second group) and C5 (bothgroups). In both groups of the pitch G5 the first dimension corre-lated with spectral centre of gravity (positively) and with the levelof the first harmonic (negatively), but levels of high frequency har-monics correlated with the second dimension together with thelevel of the second harmonic (the same sign). In both groups ofthe pitch D6 the first dimension is correlated with spectral centreof gravity and with levels of high frequency harmonics (the samesign), but the level of the first harmonic correlated with the seconddimension.


Physical Characterisation of musical instrumentsMathieu Paquier, Benjamin Robin, Théophane Foggia, Jean-Christophe BéraUniversité de BrestWe used time cues, spectral cues, and spectro-temporal cuesfor musical instrument differentiation from recordings. Twentynotes had been played on thirty instruments by one or, some-times several players for a same instrument. These notes hadbeen selected by each musician as being the most represen-tative of his instrument (various attacks, intensities, decays,crescendo/decrescendo,oe.). Then, for each of these notes, we


calculated the different cues, e.g. spectral centroïd, peak fac-tor, harmonics synchronisation, attack- and decay-duration, oe..The means and standard deviations of the different cues alloweda tree-structure-based classification of the instruments. For ex-ample, one cue differentiated the instrument families (e.g. brassfrom rubbed strings). Then, an other cue differentiated an instru-ment from an other in a given family (e.g. the violin, the cello,or the double bass within the rubbed strings family). The mainapplication of such a classification is the automatic recognitionof instruments for audio signal indexing and automatic musicaltranscription.


Réponses impulsionnelles d’un jet de flûte à becHagop Ohanessian, Jean PerrigotInstitut National des Sciences Appliquées de LyonNew methods are proposed for important steps of real time com-puting for jet displacements generated by pipe sounds. TheFletcher formula for 2-dimensional laminar jets as revisited byVerge and coll., taking the jet viscosity into account, and requir-ing a solution of free jet perturbation, is used . To perceive theformula hypothesis, a simple channel exit model ( a little cylin-drical area replacing each edge) is presented which links theFletcher formula to Euler equations for uncompressible fluids andthe foundations of the Rayleigh equation are reviewed . Thechannel immobility generates a displacement term sensitive tosound frequency and jet speed. To compute easily its contribu-tion, only the unit impulse response Fref(t) for a defined jet speed,the ”reference” one, is put in computer’s memory. This unit im-pulse implements our choices (approximations discarded, am-plitudes and phases computed together) and solves problems ofsampling’s unwanted periodicities, accuracy of samples of Fref(t).Actual jet speed is taken into account by calculated memory ac-cess: Fref(t) becomes a big array in which are calculated theaddress and a level correction of the wanted sample according toa proposed formula. In this way, the actual unit speed impulse re-sponse F(t) is obtained. The computing of jet displacements usesa convolution: s(t)=v(t)*F(t); v(t) is the speed of the acoustic fieldnear the channel exit and F(t) the unit speed impulse response;these speeds are easier to calculate than displacements. Appli-cations: sounds simulation, study, adjustment software.



Ondes mobiles et résonateur conique des flûtes à becHagop Ohanessian, Jean PerrigotInstitut National des Sciences Appliquées de Lyon. Baroque recorders exhibit a slightly tapering conical pipe, whichis easy to adjust by use of specific reamers. The musical notesare played by opening finger holes on the pipe. So, we thinkthe pipe as a fictitious set of incomplete conical segments, suchas any localized impedance (mouth, finger hole, end of the pipe,joints between recorder’s constructional parts) stands at the asegment’s beginning or end . For each segment, we define twocharacteristic impedances: for progressive (to the end) and re-gressive (to the mouth) waves, one input impedance and two re-flection ratios: for pressure and flow. These parameters may becalculated from the end segment to the mouth one. The Bergeronmethod formulates the pressure and flow variations seen, be-tween two consecutive points of reflection, by fictitious observersrespectively ’linked ’ to the progressive and the regressive wave.Of course we establish a formulation for tapering pipes, and weobtain time-dependent linear discrete equations between pres-sures or flows on the segment faces. The results are applied tothe simulation of the pressures near mouth and first finger hole.The mouth pressure computing requires the equations and thereflection function of the first segment. But the finger hole pres-sure may be calculated without convolution, and is taken into ac-count to obtain a realistic spatial pressure.


Audiotactile simultaneity perception of musical-producedwhole-body vibrationsMichael Daub, M. Ercan Altinsoy”Institute of Communication Acoustics, Ruhr-Universität Bochum;jetzt: VISATON GmbH & Co. KG”In many situations, presentation of music causes whole-body vi-brations (such as classical music concert in a concert hall, organmusic concert in a church, or in a popular music concert). In lit-erature, most studies have concentrated upon the annoyance ordiscomfort of whole-body vibrations. However, the whole-bodyvibrations which are generated by musical excitations (stimula-tions) have pleasant and informative sensations on listeners. Thisstudy concerns the interaction between whole-body vibrationsand auditory stimulation which are generated by musical events.For this purpose, the characteristics of the ”musical” whole-bodyvibrations have been investigated through measurements. In this


sense, the correlation of cross-modal perception has been ex-plored with psychophysical tests. Using statistical methods anddiscussing the results, indicators for mechanisms of cross-modalperception could be found. In this talk, investigations which arerelated with temporal aspects of musical auditory-tactile interac-tion will be presented.


Period doubling on cylindrical reed instrumentsJean Kergomard, Jean-Pierre Dalmont, Joel Gilbert, PhilippeGuillemainLMA CNRSPeriod doubling phenomena are expected to be possible on self-sustained instruments, at least since the famous paper by Mc In-tyre et al (1983). Some theoretical papers have been written con-cerning cylindrical reed (i.e. clarinet-like) instruments, discussingthe possibility of period doubling. In 1995 Kergomard has shownthat for the simple model based upon the Bernoulli equation, ig-noring losses in the resonator, period doubling, triplingoe can oc-cur, depending on the dimensionless parameter characterisingthe fit between reed and resonator. On the experimental point ofview, if such a behaviour has been observed on a bassoon, it isdifficult to obtain for cylindrical reed instruments. Nevertheless,using a crumhorn with a soft plastic reed, Gibiat and Castellengo(2000) got period doubling. The first aim of this paper is to extendthe theoretical analysis when resonator losses are taken into ac-count : analytical calculation when losses are independent of thefrequency shows that the range of parameters for which perioddoubling occurs is small. Above a rather small value of the lossparameter the phenomenon disappears. This fact can explain thedifficulty to observe the phenomenon on a clarinet. The secondaim is to confirm the previous result by using a real time synthe-sis method (Guillemain et al, 2003). Moreover synthesis allows tolisten sounds and transitions with values of the parameters whichare non common in practice : in certain cases even chaos canoccur. Auditory examples will be given.

Mo. 14:30 Kleber Thermo- and flowacoustics

Numerical Simulation of the Noise Generation at the OutletSection of Combustion ChambersChristoph Schemel, Frank ThieleTechnische Universitaet Berlin, Hermann-Foettinger-Institut fuerStroemungsmechanikCombustion noise has become an increasingly important com-ponent of total aero-engine noise, especially during the landingapproach of modern aircraft. In this flight regime, the reduction


of combustion noise has become a particular goal of efforts tooptimize sound emission. Combustion noise is understood to bea conglomerate of direct and indirect noise. The indirect com-bustion noise, addressed by a numerical method here, is radi-ated from an acceleration zone downstream of the combustionchamber. A change in state together with a fluctuation in en-tropy is identified as the source mechanism for this indirect noise.This change in state is brought about by the acceleration of anentropy fluctuation through a nozzle flow. The relationship be-tween direct and indirect combustion noise, however, is outsidethe scope of this work. The approach for the simulation of radia-tion and propagation of indirect combustion noise is based on thelinearized Euler equations coupled with a Computational Aeroa-coustics (CAA)-method. The numerical method employing the4th order DRP scheme is first verified by comparison to a com-pact theory from literature. The CAA method is applied to internalsubsonic nozzle flows with non-compact entropy wave propaga-tion. The sound pressure level (SPL) in the numerical examplesgiven grows with increasing contraction ratio of the nozzle.


Strategies for Coupling Large-Eddy Simulations with Com-putational AeroacousticsFelix Flemming, Amsini Sadiki, Johannes JanickaInstitute for Energy and Powerplant Technology, TU DarmstadtTo describe the noise generation in turbulent combustion sys-tems, it is important to capture the fluctuating density which actsas a volume source of sound - the volume of the flame fluctuateswith the reciprocal of the density. In the reactive case and forsmall Mach numbers, the main cause for the density fluctuationsare fluctuations in the heat release by the chemical reactions inthe flamefront. This heat release can be related to the acousticalpressure fluctuations. The main issue is then to get an accu-rate description of the fluctuating heat release. Following a con-served scalar approach, the latter can be expressed as a func-tion of the mixture fraction. While large-eddy simulations (LES) ofthe reactive flowfield enable a time dependent description of theheat release, acoustic approaches in the frame of computationalaeroacoustics (CAA) determine the acoustical field. Here, meth-ods like the acoustic perturbation equations (APE), the boundaryelement method (BEM) or the equivalent source method (ESM)utilize the time dependent heat release and its influence on theflowfield to predict the propagation of the noise into the far soundfield. To combine the two fields - fluid dynamics/combustion andacoustics - with its individual approaches enables a detailed de-scription of the combustion noise. For this purpose one needs


to define common interfaces, on which the exchange of data isbased. In this contribution the coupling strategies for the datasupplied by means of the LES with the CAA approaches are ad-dressed.


Modelling of the Combustion Noise by means of the Equiva-lent Sources MethodRafael Piscoya, Martin Ochmann, Haike Brick, Peter KöltzschTechnische Fachhochschule BerlinThe present work shows the advances in the development of theEquivalent Sources Method (ESM) to predict the noise producedby aerothermic sources, particularly the noise from a free flame.This method, which has been applied with very good results tothe description of noise from vibrating bodies, can be well cou-pled with a Computational Fluid Dynamics (CFD) technique todescribe the noise from combustion processes. A CFD code isused for solving the complicated non-linear equations that gov-ern the processes in the interior and near surroundings of theflame. However, such a CFD method is inappropriate for farfieldnoise determination. Instead, the ESM can easily be used to cal-culate the sound radiated into the far field from data of soundpressure or sound velocity on a control surface that contains thesource. The original source is replaced with elementary sources(monopole, dipoles, etc.) that produce the same field at the con-trol surface as the flame itself. The surface must contain the zonewith turbulence or non-uniform flow in order to obtain reason-able results. The sound power and radiation patterns from a freediffusion flame are presented. The nearfield turbulent flow wassolved using a Large Eddy Simulation (LES) code. The acousticquantities were calculated by using ten concentric cylinders withincreasing radius as control surfaces in order to see how the re-sults depend on the distance between the flame and enclosingsurfaces. The agreement of the results with corresponding BEMcalculations is very good.


A Hybrid Approach to analyze the Acoustic Field based onAeroacoustic and Thermoacoustic EffectsThanh Bui, Wolfgang Schröder, Matthias MeinkeAerodynamisches Institut AachenA hybrid LES/CAA approach to simulate sound fields generatedby aeroacoustic and thermoacoustic effects will be presented.Acoustic perturbation equations are used, which are capable todescribe acoustic wave propagation in a non-uniform mean flowsuch that the computational domain of the flow simulation has


to comprise only the significant acoustic source region. The in-put data to evaluate the acoustic source terms are generatedby an LES computation in a flow region that contains all majoracoustic sources. Special care is taken on Combustion Noisein which a sound field of an unbounded flame is simulated. Be-sides a fourth-order DRP-Scheme (Dispersion Relation Preserv-ing) for spatial discretization a LDDRK-Scheme (Low Dissipationand Low Dispersion Runge Kutta) is used for time integration. Byanalyzing the sound radiation into unbounded space the needarises due to the limitation of computational resources to intro-duce artificial boundaries to make the computational domain fi-nite, such as PML (Perfect Machted Layer) or Sponge Layer, toavoid unphysical numerical reflections into the computational do-main.


Investigation of combustion noise by real time laser mea-surement techniquesAnton Winkler, Johann Wäsle, Thomas SattelmayerTechnical University of MunichIn open turbulent premixed flames the volume of the reactionzone is time dependent. This leads to a temporal fluctuation ofthe heat release resulting in noise production. As long as thecombustion process proceeds in the flamelet-regime there is astrong coupling between the local reaction rate and the flame sur-face. Consequently, the noise production of the flame becomesfinally accessible by determination of the surface fluctuation. Un-fortunately most measuring methods integrate along the opticalaxis, which leads to the loss of local information. Thus, there areset up light sheet techniques to visualize the flame fronts withhigh temporal and spatial resolution. One of the procedures isbased on the laser induced fluorescence of OH-molecules, whichindicates the edge of the reaction zone. In addition a second pro-cedure was developed, feeding an evaporating tracer in the gas.The reaction zone is estimated from the absence of this tracer.Due to the different physical effects their qualification for the im-age post processing and their application for the noise productionof open turbulent premixed flames has to be checked.


Non-stationary Phenomena at the Firing of a Small ThrusterJean VarnierONERANon-stationary phenomena at the firing of a small thruster (thema: Aeroacoustics) In the framework of Ariane 5 program supportedby CNES, the ONERA has carried out experimental studies of the


blast wave which occurs at the ignition of solid-propellant rocketengines. A thruster is a small rocket of very short combustiontime, that allows to isolate the non-stationary phenomena oc-curring at its ignition. The thruster is horizontally fixed above areflecting ground. The sound field is measured along a linearmicrophone array aimed towards the nozzle, and along a large-radius nozzle-centered microphone arc. It is interesting to noticethat two successive shock waves are recorded in fact: the firstone corresponds to the breaking of the nozzle shutter during therise of the chamber pressure; the second one, more important,occurs during the short stationary phase of the pressure. Thelatter phenomenon was rather unexpected and has been studiedmore particularly. It is established from three different methods(time shift between the microphones, time lag of the reflectedwave, spatial correlation functions) that the second shock-frontcomes from a point located at about one meter downstream fromthe nozzle. Thus, the origin of this wave is not the nozzle but the’fireball’ formed in the air by the gaseous combustion products.


Numerical Sound Prediction of Open Rotors: Methods, Re-sults and PerspectivesIris Pantle, Esra Sorgüven, Franco Magagnato, Martin GabiFachgbiet Strömungsmaschinen, Geb. 10.91, 2. OG., UniversitätKarlsruheThe numerical sound prediction of open rotors underlies spe-cial requirements due to the complexity of their geometry andflow. As far as one aims to find an overall valid numerical pre-diction method for aero-acoustics without relying on empirical orsemi-empirical data the classical Computational Fluid Dynamics(CFD) approach suggests similar methods tailored to acousticalproblems. Presently within the field of the so-called Computa-tional Aero-Acoustics (CAA) there are several methods available.Basically these extract unsteady acoustic sources out of a flowcomputation and proceed with the computation of the acous-tical wave propagation through a fluid. In respect of applyingthe method to subsonic open rotors such as fans a combinationof unsteady Reynolds Averaged Navier-Stokes (URANS) com-putations or Large Eddy Simulation (LES) together with a formof Acoustic Analogy, preferably the Ffowcs Williams and Hawk-ings Analogy (FWHA), does not only produce reasonable resultsbut also shows appropriate but nevertheless feasible demand ofcomputing resources. Within this presentation a brief overviewof the functionality of the acoustic module implemented in the in-house CFD solver and using FWHA will be shown. There willbe presented three case studies, realized by using LES and the


FWHA, including a 3-dimensional flow around a circular cylinder,a flow around a combination of a cylinder and an airfoil and aflow through a simple, but completely 3-dimensional, subsonicpropeller. The configurations follow experimental settings for thereason of comparing numerical and experimental results and val-idating this approach.


Computation of Trailing Edge Noise with Turbulence in Lin-earized Euler EquationsMarcus Bauer, Andreas ZeibigInstitut für Akustik und SprachkommunikationAirframe noise plays a very important role in road traffic, rail trafficand air traffic. Its direct computation, however, can hardly be ac-complished with presently available computers and hence is notapplicable for industrial design. This research attempts to com-pute broadband trailing edge noise as a special case of airframenoise using a cost-saving hybrid method. In the first step thetime-averaged mean-flow field around the object is computed bysolving the RANS-equations (Reynolds Averaged Navier Stokes)and in the second step the time dependent noise is obtained bysolving a modified form of the LEE (Linearized Euler Equations)with a source term. The latter is driven by a synthetic turbulencefield and is used to excite turbulence in the LEE. Results of thecomputed trailing edge noise of a profile and a flat plate are pre-sented. In both cases good agreement with solutions obtainedby other researchers is found. The computations are validatedwith measurements in the institute’s own aeroacoustic wind tun-nel. Single and triple sensor hot-wire probes are employed forthe aerodynamic measurements while single microphones and amicrophone array, respectively, are used for the acoustic mea-surements. The method seems to be suitable to compute and toinvestigate trailing edge noise, but additional research is requiredconcerning the excitation of turbulence in the LEE.


Control of Pipe Flow Resistance by SoundMatthias Jüschke, Dirk RonnebergerDrittes Physikalisches Institut GöttingenWe have investigated the sound propagation through a rigidwalled circular flow duct with a short section having yielding walls(lambda/4-resonators). We have observed strong amplificationof sound waves that travel downstream at frequencies slightlyabove the resonant frequency. The energy of the amplified wave


is taken from the mean flow. Thus the flow resistance of the yield-ing duct section increases depending on the amplitude of the inci-dent sound [Brandes, Ronneberger, DAGA 95,96], i.e. the yield-ing duct section acts as a fast reacting sound-controlled valve.This includes, among others, the possibility to generate soundat abitrary low frequencies [Lange, Ronneberger, DAGA 99]. Insuch applications of the effect, the amplified control sound is un-welcome. Therefore we searched for higher order modes whichare evanescent in the rigid duct but are strongly amplified in theyielding duct. A rectangular cross section of the yielding ductwas chosen for this purpose. Surprisingly we found a spectrumof instabilities quite different from the circular duct. In particularthe outstanding instability which was responsible for the flow con-trol in the circular duct has no correspondence in the rectangularone. Possible reasons for this will be discussed.


Transient Behaviour of a Thermoacoustic Refrigerator :model and experimentsGaelle Poignand, Pierrick Lotton, Philippe Blanc-Benon, MichelBruneau, Vitali GusevLAUMNowadays, the expression of the temperature difference acrossthe stack of a thermoacoustic refrigerator can easily be obtainedin steady states, but models for analysing the transient processare still in progress. More precisely, previous models used to de-scribe the behaviour of thermoacoustic devices usually assumeseveral approximations preventing us from describing the tran-sient behaviour of the temperature field. Particularly, heating dueto viscous effects at the interfaces between the walls and thefluid in the thermoacoustic stack and thermal losses are usuallyneglected. Therefore, the parameters which govern the transientresponse, its shape and its characteristic stabilisation time arenot fully identified. Thus, the aim of the present work is to in-vestigate more deeply, analytically, the transient behaviour of thethermoacoustic refrigerator, using a revisited description for thetemperature variations in the stack due to thermoacoustic pro-cess, by introducing new features as heat losses through thethermoacoustic system and viscous heating in the boundary lay-ers near the walls. The phenomena has been modelled in termsof a system of a coupled differential equations, including both anon-homogeneous linear second order partial derivative equa-tion reduced to an equation with constant coefficients and a setof differential equations, derived from the given physical situation,corresponding to initial and boundary conditions. Apart from nu-merical methods which can provide the behaviour of the transient


to interpret the experimental results recently available, the goal isto obtain approximate analytical solution to interpret the physicalphenomena which underlie the viscous and thermal phenomenacoupled together.


Transient nonlinear processes in annular thermoacousticenginesGuillaume Penelet, Vitali Gusev, Pierrick Lotton, Michel BruneauLAUMAn annular thermoacoustic prime-mover transform thermal en-ergy into acoustical energy using the thermoacoustic interac-tion between an inhomogeneously heated stack of solid plates(placed in an annular waveguide) and resonant gas oscilla-tions. In such a device, the saturation of the acoustic waveamplitude leading to the stationnary regime is linked not onlyto classical nonlinear phenomena such as cascade process ofhigher harmonic generation and minor losses, but also to non-linear processes influencing the temperature distribution in theinhomogeously heated parts of the system such as acousticallyenhanced thermal conductivity and acoustic streaming. Thepresent study aims at describing the own contribution of each oneof those nonlinear processes by means of experimental observa-tion and analytical description of the transient regime. Experi-mental observations of the transient regime are briefly reported.The obtained results show various regimes, demonstrating thepossibility for the engine to turn on and off spontaneously and pe-riodically, the possibility for an overshoot of the acoustic wave am-plitude before its final stabilization, or the possibility for a double-threshold process during the amplification regime. A simplifiedtheoretical model is then presented, where the one-dimensionalheat transfer equation is coupled to the acoustic problem by tak-ing into account the forced convection due to acoustic streamingand the acoustically induced thermal conductivity. Thermoacous-tic amplification depends in its turn on the temperature distribu-tion along the stack and the waveguide. The obtained resultsnotably provide a qualitative explanation for the double-thresholdphenomenon.


Concepts and Realization of Acoustical TomographyPeter Holstein, Armin Raabe, Roland Müller, Manuela Barth,David Mackenzie, Eric StarkeSINUS Messtechnik GmbHTomographic techniques are powerful tools for obtaining insightinto physical or chemical properties of areas and volumes. There


is also a trend to develop these procedures for non-stationaryconditions. We present the realization of a prototype version ofa tomographic system for industrial and scientific applications. Itincludes conceptual work on several levels. Firstly, the hardwareof the system should consist, as far as possible, of an existingproduct - a multi-channel system with active output. The hard-ware solution can be applied under a variety of conditions (scal-able areas/volumes, adaptive frequencies appropriate to the tar-get and to the physical problem, resilience to background noiseetc.). This will be discussed in the technical part of the talk.Secondly, a general software concept (including several layers ofreal-time and near-real-time algorithms, inversion techniques andthe user interfaces) will be presented and applied to the tomo-graphic system. MATLAB toolboxes for control, algorithms andpresentation form the core of the numerical tomography concept.It will be demonstrated that the concept can be applied to to-mographic problems of various sizes (scalability). Two examplesare given which demonstrate the scalability of the concept. Asmall-scale model-size experiment (for educational purpose) ofabout 1 square meter and an example indoor climate investiga-tion (for a sports hall) are presented. It is intended to use thetomographic system for educational purposes as well as for thetraining, preparation and realization phases of expensive mea-surement campaigns.

Mo. 14:30 Oberlin Physical acoustics I

Numerical Simulation of Bounded Acoustic Beams by theFourier Integral MethodPhilippe GatignolLaboratoire Roberval, CNRS, Université de Technologie de Com-piègneA bounded acoustic beam, such as the one generated by a finitetransducer, may be classically described by plane wave super-position. In the monochromatic case, the pressure field is thenobtained in the form of a spatial Fourier integral. Analytical ex-pressions of such integrals are out of reach in general and onlyasymptotic or numerical evaluations are available. The numericalevaluation of Fourier integrals is usually performed by the FFTalgorithm. This procedure requires to introduce a regular dis-cretization of the integration variables and a corresponding setof values of the conjugate variables. The pressure field is thusobtained for a particular set of points in the space. Moreover,the regular discretization results in an artificial periodization ofthe solution. A direct numerical evaluation of Fourier integrals byclassical methods such as Lagrange method avoids to prescribe


specific positions of the points in the physical space, but the pe-riodization phenomenon is not overcome. We propose a methodbased on partial exponential integration of the Fourier integrals.The acoustic beam is then obtained in any point of the physicalspace without any periodic artefact. This kind of numerical simu-lation of a bounded acoustic beam is relevant of those problemswhere the beam interacts with a multilayered structure, with longrange propagation effects, in particular when a modal wave isgenerated in the structure.


Surface Acoustic Wave Propagation on Spheres and Cylin-ders Using Laser Ultrasonics : Analysis and ExperimentsDominique Clorennec, Daniel RoyerESPCI - LOAWe have observed that a short Rayleigh wave pulse propagatingon a cylinder or on a sphere was reversed during its first half-turnof propagation. Experiments were performed on steel and dura-luminium samples with transient surface acoustic waves (SAW)launched by a pulsed YAG laser focused along a line. The radialcomponent of the displacement was measured by a heterodyneoptical interferometer. The waveforms recorded versus the an-gle between the source and the detection points shows that theRayleigh pulse, which is for example monopolar (positive) nearthe source, becomes bipolar at an angle equal to 45◦, monopolar(negative) at 90◦ and monopolar (positive) at 180◦. In the case ofa cylinder, we demonstrated that this unexpected phenomenoncould be ascribed to the dispersion effect on the high frequencycomponents of the laser-generated acoustic pulse. We analysedthe variation of the inversion angle versus the material Poisson’sratio and we show that for large cylinder radius the diffraction ef-fects must be taken into account. In the case of a sphere, thecurvature along the line source compensated the diffraction ef-fects. Then the inversion angle does not depend on the samplediameter. In the last experiment, we replaced the line by a pointsource and we studied the focalisation effect of SAW in the vicin-ity of the opposite point.


Sound Field Modelling in a Narrow Street by the TransportTheoryThierry Le Pollès, Judicaël Picaut, Michel BérengierLCPCIn this paper, we present an original approach for the diffusesound field modelling in a narrow street. Using the concept of


sound particles, we show that the temporal and spatial distribu-tion of sound energy in a street may be solution of a transportequation, where the boundary conditions are defined for mixedspecular-diffuse reflections. In order to apply this model, anasymptotic solution is detailed. In this case, we show that thetransport equation may be reduced to a diffusion equation for thesound energy, where the diffusion coefficient depends only on thestreet width, the ratio of specular and diffuse reflections, and thediffuse reflection law. In order to validate the model, measure-ments have been carried out in a narrow street and comparedwith the solution of the diffusion equation. The results show thata good agreement is obtained, both for the sound levels and thereverberation times in the street.


Radiation of Directional Seismic Sources within a LayeredHalf SpaceMadjid Berraki, Bertrand Dubus, Axelle BaroniInstitut d’Electronique de Microélectronique et de Nanotecholo-gie, UMR 8520 CNRS, département ISENThe aim of 4D-surveying, a recent development in seismic, is tomonitor the changes in the subsurface in time. Thus, measure-ments are continuously repeated with the same space configu-ration : reliability and repeatability of the acquisition footprint arekey requirements for 4D surveys. The Weathered Zone (WZ) isthe main cause of source signal fluctuations, polluting the sig-nal coming from reservoir variations. This zone is directly lo-cated beneath the surface and its mechanical properties varywith weather. To eliminate this perturbation, a directional source,buried under the WZ and radiating downwards, is analyzed here.Two models are developed considering that the source size towavelength ratio is small. Firstly, Green’s tensor for the half spaceis derived using the Cagniard De Hoop’s method (CDHM, [1]).Two signals are used to compute synthetic seismograms for thedirectional source : a quasi harmonic excitation, which providesradiation patterns of the source, and a Ricker signal (gaussianin the frequency domain) which is a typical seismic signal. Sec-ondly, a source buried in a half space covered by a layer (theWZ) is considered. As the CDHM, would be intricate in thiscase, the Green’s tensor in a layer is computed using the Dis-crete WaveNumber Method (DWNM, [2]). The solution is thenpropagated using the reflectivity method. Seismograms are com-puted for different WZ properties to validate the directional sourceconcept. References [1] Johnson, L. R., 1974. Geophys., J., R.,astr., Soc., 37, 99-131. [2] Bouchon, M., 1981. Bull., Seism.,Soc., Am., 71, 4, 959-971.



Propagation of Lamb waves in anisotropic rough platesCatherine Potel, Claude Depollier, Damien Leduc, Bruno Mor-van, Pascal Pareige, Jean-Louis IzbickiLAUMIn this paper, the propagation of Lamb waves in a plate ofanisotropic solid with a randomly rough surface is studied. Theprofile of the surface is described by its statistical properties: itsmean value and the mean square deviation of the surface fromthe flatness. In the small roughness limit, the dispersion relationof the Lamb waves is derived from an effective boundary con-dition by a perturbation method. In this model, the roughness ofthe stress-free boundary induces a small complex perturbation ofthe dispersion relation: the real and imaginary parts of which arerelated respectively to the shift frequency and to the attenuationof the wave. Analytical and numerical results are presented forboth the shift and the attenuation of the waves, showing that twomechanisms contribute to the decay of a Lamb mode: its decayinto bulk elastic waves and its decay into other Lamb modes. Ex-perimental results are presented in glass plates and duraluminplates are compared to the theoretical results.


Acoustic waves generated by a pulsed laser in anisotropicsemiconductorsBertrand Audoin, Hinde Meri, Clément RossignolLaboratoire de Mécanique Physique, Université Bordeaux 1When a laser pulse is focused at the surface of a material, thetransient heating of the semi-transparent material induces ultra-sound. The subsequent acoustic generation and propagation hasbeen extensively described even when the material behaviourshows anisotropy and viscosity. However, when a 1064 nm laserpulse is focused at the surface of silicon, it has been observedthat the material contracts whereas heating should produce ex-pansion. In addition to the usual thermal acoustic source, a nonthermal sound excitation results of photo excitation of electron-hole pairs. Therefore, to describe the optoacoustic effect insemiconductors it is necessary to account for thermoelastic andother deformation sources simultaneously. In this presentation,a model is implemented that accounts for the diffusive charac-ter of charge carrier motion and heat conduction. Relevant dif-ferential equations are coupled together and with the wave mo-tion equation. Three sets of equations are linearised in a 2D


Fourier domain and solutions are found with an appeal to conve-nient boundary conditions. Signals are calculated for off epicen-tre positions at the rear side of the anisotropic semiconductor.Experiments are performed on a 5 mm thick silicon plate with aNd:Yag laser that delivers 20 ns pulses. Signals are measuredfor epicentre and off epicentre positions. Very good agreementis obtained with calculated signals for both positions demonstrat-ing that both sound generation mechanism and anisotropy areaccurately taken into account.


Laser-induced thermoelastic excitation of plane shearacoustic pulsesDenis Mounier, Moussa Hazmoune, Nicolay Chigarev, ThomasPézeril, Pascal Picart, Samuel Gougeon, Jean-Marc Breteau,Vitali GusevLaboratoire de Physique de l’Etat Condensé, UMR- CNRS 6087,Université du MaineA simple theory is developed and numerical estimates are pre-sented to demonstrate the possibility of directly exciting planeshear acoustic pulses by distributed laser-induced thermoelasticstresses. It should be mentioned that in the most of the experi-ments conducted until now shear waves are excited not directlythrough thermoelastic effect but through the mode conversion atthe surfaces and interfaces of the longitudinal acoustic pulses(excited due to thermal expansion). The direct excitation of shearwaves through thermoelasticity is possible due to anisotropy ofthe crystal thermal expansion. To use this anisotropy the orien-tation of the laser-irradiated surface relative to the crystal sym-metry axis should be optimised. We analysed in details the caseof the hexagonal crystals, where the efficiency of the thermoe-lastic excitation of the plane quasi-shear, and of the plane quasi-longitudinal waves (launched normally to the irradiated surface)depends on the orientation of the surface relative to the crys-tal axis. The preliminary results of the experiments in Zn singlecrystals, where the laser interferometry is used for the detectionof the nanosecond shear acoustic pulses thermoelastically ex-cited by nanosecond laser pulses, are also reported.



Elaboration of a scattering matrix measurement procedurefor higher order acoustic duct modes propagation condi-tions.Azzedine Sitel, Jean-Michel VilleLaboratoire Roberval, CNRS, Université de Technologie de Com-piègneA method for measuring the scattering-matrix of duct disconti-nuities for higher order acoustic modes propagation conditionsis being developed and progress is presented in this paper.The technique, as this previously used for measuring trans-mission and reflection matrices, is based on measurement ofacoustic pressure in two closed cross sections which separateincident and reflected modes after a modal decomposition byFourier-Lommel’s transform for N linearly independent pressuresource distributions on N cut-on modes. Following works alreadyachieved for plane wave propagation conditions, the determina-tion of the scattering matrix coefficients is deduced after repeat-ing all the experiment for two inlet charges which create the con-ditions for solving the system of equations. The experimentalset-up, the signal processing and the data treatment process aredescribed. Experimental results of the scattering matrix coeffi-cients of a hard wall duct test section without any discontinuityfor pressure distributed on the first three cut-on modes (0, 0); (1,0); (-1, 0) are discussed.


Variation in Time and Spread of Quantiles (Percentiles) ofStochastically Fluctuating RMS Sound PressureAlois HeißBayerisches Staatsministerium für Umwelt, Gesundheit und Ver-braucherschutzIn sound measurement besides the level Leq and other descrip-tors also the quantile of type ’N percent exceedance level’ isused. Within the measurement techniques standardized untilnow these quantiles are determined by counting the populationof sound pressure level classes. But by this procedure no use ismade of statistical structural data additionally embedded withinthe stochastic fluctuations in time althoug these data are rele-vant for the uncertainty of the measurement. This deficiency isto be eliminated for sake of adequately taking into account allcontributions which determine significantly the quality of soundimpact assessments. The quantile’s dependance on time can beconcluded from the quantile definition applied onto the primarycontinuous, usually stochastically fluctuating rms sound signal.


From this follows that also the quantile varies stochastically. Af-ter a sufficient number of fluctuations the quantile variation canbe linearized and the spreads can be extracted directly as for thequantile as for the exceedance relative to a fixed quantile level.The resulting relations are calculable by the outcome of measure-ment itself. Thus also the confidence limits (c. l.) of quantiles aredeterminable in real time by measurement. For the Leq, the as-sociated c. l. are calculable by integration of the quantile c. l.over the exceedance variable space, i. e. from 0 to 1. Main fea-tures and possible applications of these relations are presented,already available for the every days measurement practice by acommercial measurement software for online sound level qualitycontrol.


Vibroacoustic Testing of Technical Plastics ComponentsAndreas Franck, Jürgen GrafInstitute of Technical AcousticsDue to their often small stiffness and their associated affinity tovibration, plastics components contribute much to sound radia-tion in many technical systems. An acoustics-aware design ofthis components is therefore of special importance. Computersimulations of the vibration behaviour only supply a first approx-imation of the real performance, because complicated materialmodels with often unknown or hard to obtain parameters arenecessary to describe the material properties over an acousti-cally relevant frequency range. For the vibroacoustic analysis,a 3D laser vibrometry scanner has been combined with a cor-relation measurement system, providing the mechanical excita-tion with a shaker. Systematic measurement errors of the setupare compensated with a special calibration approach. An au-tomated data transfer between CAD models, laser vibrometryand post processing applications provides fast adaption to dif-ferent part geometries. A matching of the simulation models withthe real behaviour therefore requires a vibroacoustic testing ofthe plastics components. This paper discusses the vibroacoustictesting of several technical plastics components. The necessarysteps for a methodically founded comparison between simulationand measurement results are presented. Finally, possible ap-proaches for both the subjective and objective interpretation ofsimulations, measurements and the acoustical reality are shown.



A simple method of determining the sound absorption coef-ficient at oblique incidenceXiaoru Zhou, Xueqin ZhaFraunhofer Institut BauphysikThis paper proposes a simple method for estimating the soundabsorption coef-ficient at oblique incidence in an anechoic en-vironment. The frequency de-pendent sound pressure (directsound) is first measured at one microphone po-sition without anyreflecting plane. In a second step a reflecting/absorbing ma-terialis inserted and the sound pressure measured again. The directsound and the reflected sound cause interference at the micro-phone position. The pattern of interference depends on the ab-sorption characteristics of the material to be tested. By analysingthe interference pattern the absorption coefficient of the test ob-ject at oblique incidence can be calculated. This method can dowithout any complicated instruments and calculation procedures.More specifically, it yields a fast and precise estimate of the ab-sorption ability of larger acoustic modules and linings.


Interpolation of complex frequency response curvesJoerg Panzer, Charalampos FerekidisConsultant - R&D TeamThe interpolation between two complex frequency responsecurves, such as obtained from turntable directivity measurementsis investigated. The direct application of interpolation algorithmsto response data, either in frequency or time domain, may causeinterference patterns and, due to this, does not yield the expectedresult. This paper demonstrates the problem and offers a solu-tion, which takes into account the multi-valued property of theexponential function of the phase term.


Mo. 14:30 Arp 1 Measuring methods in building acoustics I

Evaluation of procedures to determine uncertainties in build-ing acoustic measurementsHans GoydkeTechnische Universität BraunschweigIn order to determine uncertainty values according to the GUM ofsingle number quantities being the final results of several buildingacoustic measurement procedures two basic tasks excist. Theone is to establish procedures for the determination of the un-certainty of the single number from the uncertainties of the mea-surement results in the third-octave or octave-bands from whichthe single number is dereived. The other is the evaluation ofprocedures to establish the uncertainty budgets for every mea-surement result in the different frequency bands. Solving the firsttask it occures that the Monte-Carlo method is well suited to beused with ”shifting reference curve procedures” as they are re-lated besides others to the airborne sound insulation index Rw.For the quantities to be used as European harmonized ones (f.i.RA,1 = Rw + C) a much simpler ”linear calculation method” canbe applied as well as the Monte-Carlo procedure. In order to findsolutions for the second task results from several internationalRound Robins and also from national comparison measurementsare gathered and analyzed. First results will be shown.


Some remarks on the uncertainties associated with the labo-ratory measurement of noise from waste water installationsVolker WittstockPhysikalisch Technische Bundesanstalt, FB 1.6 SchallLaboratory measurements of noise from waste water installationsare mainly carried out for two purposes. The first one is to as-sign individual values to different types of waste water installa-tions with a view to comparing their acoustic properties, and thesecond one is to predict the noise from such systems as earlyas at the design stage of a building. The measurement proce-dure described in prEN 14366 was developed to reach these twopurposes. The measurement is carried out in a usual test suiteand the waste water system is mounted in the sending room onthe wall between sending and receiving room. One measure-ment result is the sound pressure level in the sending room whichmainly is a result of direct radiation from the waste water system;another result is the sound pressure level in the receiving roomwhich is assumed to be a measure of the ability of the source toemit structure-borne sound into the building. To obtain compara-ble results for the latter, the structural sensitivity of the mounting


wall is normalized to a standardized sensitivity. The paper dealswith several assumptions for this measurement procedure. Oneof these is that the structural sensitivity at the two mounting po-sitions is averaged, whereas a detailed analysis reveals that thisaveraging is valid only in some special cases. Another assump-tion is that the source acts as a force source and the amount ofvibratory energy emitted into the mounting wall solely dependson the properties of this wall and not on those of the source.


Describing Noise of Water Appliances by ISO 3822: Whathappens really?Heinz-Martin FischerFachhochschule Stuttgart - Hochschule für TechnikAt the moment the acoustical behaviour of valves and watertaps has to be characterized by the standard ISO 3822. Thepresent contribution describes the principles of the actual mea-surement method. Mainly the role of the so called INS (instal-lation noise standard) and the understanding of the underlyingreference source procedure will be outlined. It can be shownby basic considerations that the physical assumptions of this ap-proach inevitably will result in shortcomings which considerablycan influence the comparability of test results gained in differenttest facilities. Beyond that it can be shown that the Lap ( ) asthe final result of this standardized measurement in many caseswill not give a sufficient description of the real acoustic behaviourunder in-situ conditions. In consequence the Lap can not be con-sidered as a reliable basis for predictions of the appliance noise inthe field (this will be of importance for the new prediction modelsof EN 12354-5). Thus it is recommended to revise the completemeasurement procedure of ISO 3822 by means of methods re-lated to the emitted water and structure borne sound power (seecontribution of Alber et al at CFA/DAGA 2004).


Characterization of valves as sound sourcesThomas Alber, Michael Yankonis, Heinz-Martin Fischer, BarryGibbsFachhochschule Stuttgart - Hochschule für TechnikCommonly valves, especially water taps, are regarded exclu-sively as fluid-borne sound sources. Based on this assumption,an ISO standard 3822 has been established, which has led toconsiderable improvements regarding fluid-borne sound emis-sion of valves. However the reduction in fluid-borne sound inpart contributed to the finding, that structure-borne sound can-not be neglected a priori. In practice valves like water taps


are sources of air-, structure- and fluid-borne sound simultane-ously. Generally measurements of airborne sound power arerelatively straightforward and can be conducted using standard-ized methods. However the procedures are more complicated ifstructure- and fluid-borne sound power are to be considered, asa means to predict the acoustical performance of valves in-situ.A current research project, at the Fachhochschule Stuttgart inco-operation with the University of Liverpool, is concerned withthe sound emission of valves on a power basis, including fluid-and structure-borne sound. Preliminary results of this researchproject are presented.


Measurement of installation noise and service equipment inbuildingsAlfred SchmitzTAC Technical Acoustics ConsultDuring the last years new methods for measuring installationnoise and noise from service equipment in buildings on a unitEuropean level have been developed (EN 10052 and EN 16032).EN 10052 contains a method for survey measurements, EN16032 deals with the corresponding engineering method. Thedevelopment of these two standards has taken a long time, be-cause many technical and ’political’ problems had to be dis-cussed and solved. First of all, the estimation of the reverberationtime using a prepared table for reverberation correction is one ofthe points which has been discussed intensively in the workinggroup. In particular the categories of the room types and the es-timation precision have been of importance for some countries.In addition to that the attention has been focused on the intro-duction of a ”weighted” corner position in the receiving room formeasurement of the sound pressure level. Last but not least thedefinition of consistent operating conditions for installations andservice equipment has been a main task. However, a ”European”compromise had been found and the standards will become offi-cial soon. The paper summarizes the discussion of the technicaland ’political’ points, and explains the most important issues inmore detail.


Sound insulation test facilities yielding deviating measure-ment results although conforming to ISO 140Werner SchollPhysikalisch Technische Bundesanstalt, FB 1.6 SchallFor many years, the Physikalisch-Technische Bundesanstalt inBraunschweig (PTB) has been carrying out interlaboratory tests


in the field of sound insulation. One test of that type started in1998, with a heavy-weight masonry wall of 24 cm calcium sili-cate bricks being the test object. The interlaboratory test is stillgoing on, and participation of all laboratories wishing to obtainan official approval as a laboratory for building acoustics in Ger-many is required. Basic regulations for the construction of testrigs for sound insulation measurements are given in ISO 140-1.Although laboratories asking for an approval usually comply withthis standard, it happens once in a while that the measurementresults deviate from the mean values of the interlaboratory testto an extent which cannot be explained by the typical variance ofthe measurement. In one case, where the deviation was about15 dB around 100 Hz, PTB got the opportunity to investigate thereasons. Extensive measurements were carried out, e.g. narrow-band analysis of the sound reduction index, modal analyses ofthe airborne and structure-borne sound fields, and measurementof the total loss factor. In addition, the boundary conditions ofthe wall under test were changed. In the paper it will be doc-umented in which way the geometrical configuration influencesthe measured sound insulation and proposals be given how themeasurement can be improved.


Experimental Investigations into Attenuation in the field ofBuilding AcousticsChristoph KlingPhysikalisch Technische Bundesanstalt, FB 1.6 SchallThe Applied Acoustics Department of the Physikalisch-Technische Bundesanstalt (PTB) Braunschweig, in cooperationwith the Applied Mechanics Institute (InfAM) of the Civil Engi-neering Department of Braunschweig Technical University, is atpresent implementing a DFG project to investigate attenuation in-fluences in building acoustics. It is the objective of this researchproject to analyze the effect of attenuation mechanisms on soundtransmission in building construction. In particular, the influenceon the measurement of sound reduction in the test stand will beinvestigated and a differentiation into properties of test object andtest stand will be made. The project is subdivided into a numeri-cal and an experimental part. At the InfAM a simulation of a teststand by combined FE and BE methods will be realized. At thePTB, the predictions from the simulation will be experimentallychecked and investigated in more detail. This combination willultimately serve to develop an instrument to predict the attenua-tion in the test stand and in the building and on the other hand tooptimize the acoustic insulation of partitions. First of all, however,


the simulation results must be verified to substantiate the numer-ical predictions. For this purpose, the PTB carries out compar-ison measurements on scaled models and determines variousmaterial parameters by both, conventional and modified meth-ods. The lecture presents the project and deals with the currentstate of the investigations. It will describe the realization of thestructure-borne and of the airborne sound fields true to scale forthe dimensioning of the model, the requirements resulting for themodel material, and the measurement of the material character-istics.


Measurement of Structure-borne Sound Power of Mechani-cal InstallationsMoritz Späh, Heinz-Martin Fischer, Barry GibbsFachhochschule Stuttgart - Hochschule für TechnikThe standard EN 12354 Part 5 is being developed to allow pre-diction of the sound generated by active building componentsfound in mechanical services in buildings. It is recognised thatmuch of the noise generated by vibrating components transmitsas structure-borne sound before radiating as perceived noise inother rooms. However, there are not yet available appropriatelaboratory test methods for sources of structure-borne sound andtherefore there is not reliable input data for the predictive modelsbeing developed. The structure-borne power of a source canbe calculated by considering the mobilities of the source, the re-ceiver and the free velocity or blocked force of the source at thecontact points. This requires a great amount of data which can-not be obtained for most mechanical installations sources. A re-ception plate method is investigated as a way of reducing the re-quired data set and simplifying data acquisition. As installationscan introduce structure-borne sound into more than one surfacesimultaneously, a test rig is proposed with three resiliently sup-ported mutually perpendicular plates. The structure-borne powerinto each plate can be measured separately. The validity of thisapproach is investigated by comparison of the test-rig results withpredicted powers obtained by mobility methods. A case study ofa whirlpool bath is presented.



About the Measurement of Flanking Sound Transmission be-tween Adjacent Rooms through Lightweight WallsStefan Schoenwald, Heiko Martin, Eddy GerretsenEindhoven University of Technology - Department of Architecture,Building and Planning - Laboratory for AcousticsThe EN 12354 is a valuable tool to predict the flanking transmis-sion of air-borne and structure-borne sound between adjacentrooms. Regarding ”heavy”, monolithic structures the model is in-between commonly used in building acoustics, since a lot of datais already available for the vibration reduction index Kij that de-scribes the strength of coupling of two building elements, due tothe easy applicable measurement methods that are described inthe prEN ISO 10484. The Kij can be determined either by air-borne sound measurements or by vibration measurements thatcan be applied in the laboratory as well as in-situ. However, be-sides monolithic structures also lightweight, double leaf buildingelements exists. Unfortunately, in this case the above-mentionedprediction model is not successfully introduced yet mainly due toa lack of available data for the Kij. This is caused by the factthat mostly the indirect measurement procedure with airbornesound (prEN ISO 10484-3) was used successfully so far, whichcan only be applied in special test facilities for flanking soundtransmission. This is a great disadvantage compared to the di-rect method with structure borne sound measurements. There-fore to get a better understanding of the problem a review of theCEN-model, the measurement methods for the Kij and currentresearch work regarding the flanking sound transmission throughlightweight building elements will be presented and examples forthe application of the model to lightweight building elements willbe given.


Comparison of Different Methods for the Determination ofthe Structure-borne Noise Reverberation TimeHeinrich BietzPhysikalisch Technische Bundesanstalt, FB 1.6 SchallDue to the implementation of new measurement standards inbuilding acoustics (ISO 140 series, EN 12354 etc.), measure-ment of the structure-borne noise reverberation time has becomenecessary for the determination of some measurands of buildingacoustics. Compared to the determination of the airborne noisereverberation time, a couple of additional problems occur. De-cay processes are extremely short and the curve for the decayprocess is difficult to evaluate because of the lack of diffusivity


of the structure-borne noise fields. Different methods for exci-tation (shaker, hammer) are available, which unfortunately oftenlead to different results. This may probably be due to the interac-tions between excitation mechanism and test object. When usinga shaker for excitation, correlation signals will generally have tobe employed because of poor measurement dynamics, which re-quires quite intricate signal processing and extensive user knowl-edge. But the impulse response measured with a hammer, too,can be evaluated correctly only after applying the inverse inte-gration. Numerous tests with a heavy-weight wall to investigatethese problems were conducted in the past within the scope of anintercomparison at PTB. Experience gathered and results gainedin current tests will be reported. Different measurement methodswill be introduced and their applicability discussed.


The effect of airborne sound transmission using thestandard tapping machine as structure borne sound forlightweight stairs - problems and possible solutionsThomas Möck, Jochen ScheckSchalltechnisches Treppen-, Entwicklungs- und Prüfinstitut(STEP) GmbHWithin the scope of an acoustical research and developmentproject about the sound transmission through lightweight stairsstructural improvements considering the sound transmissionwere investigated. The investigations were carried out at our testfacility for stairs measuring the total sound pressure level which isthe energetic sum of airborne and structure borne sound trans-mission. Using the tapping machine as structure borne soundsource we found that airborne sound transmission was dominantcompared to the structure borne sound transmission when test-ing effective improvements. Therefore the correction of the air-borne sound transmission according to DIN 52210 (”Luftschal-lkorrektur”) was not possible (the actual standard DIN EN ISO140-7 doesn’t even offer a possibility for this correction). Thiscould be considered as a principal problem when we’re lookingat the structure borne sound transmission of lightweight stairswhich also often occurs when measuring the sound transmissionof stairs in top floors. In the presentation possible solutions ofthis problem are discussed.



Alternative Determination of Dynamic Stiffness of Thick In-sulating LayersPhilip Leistner, Hartmut Schröder, Bettina RichterFraunhofer Institut BauphysikThe dynamic stiffness of insulating layers is a decisive parame-ter for the sound insulation of multi-layer building parts such asfloating floors, additional linings and external thermal insulationsystems. With restriction to (mostly thin) layers of insulating ma-terials used under floating floors a measurement procedure itsregulated in the standard DIN EN 29053. Due to this restrictiona reliable procedure for insulating layers in other applications isstill needed. Especially the stiffness of very thick layers of exter-nal thermal insulation systems is hard to analyse. The mountingconditions strongly influence the results and the measurementuncertainty is generally high. These problems can be avoidedby an alternative procedure which should also be as practicalas possible. In comparison with the standard shaker excitation,which is far from reality of thermal insulation systems, an airbornesound excitation shows several advantages. In this sense theimpedance tube can be used. The measured sound absorptioncurve clearly shows the resonance behaviour of a mass (plas-ter) - spring (insulating layer) system. With the known mass thedynamic stiffness can be easily derived. Further practical condi-tions are ensured by horizontal orientation of the multi-layer sys-tem and by well-defined lateral terminations. Even the influencesof different support systems, e.g. plugs or frames, can be inves-tigated in impedance tubes with bigger cross-sections (> 1 m2).A number of tests will be presented and compared with other re-sults including results of sound insulation measurements.

Mo. 14:30 Arp 2 Global reduction of transportation noise

The ’Research Network Quiet Traffic’ - A Global Approach toReduce Transportation NoiseDietmar WurzelDLRTraffic noise has become a severe environmental problem. Noisenegatively affects the physical, psychic and social well-being.Consequently, noise reduction will improve the quality of life andis an essential element of health protection. The global attenu-ation of noise from road, rail and air traffic is an ambitious goal.Mobility and thereby economical progress must be guaranteedwhile transportation noise is reduced despite increasing trafficdensity. To provide an enabling and interdisciplinary approach


for the coordination of all noise abatement efforts across traf-fic branches, the research network ’Quiet Traffic’ was foundedin Germany in 1999. 70 partners from academia, research in-stitutions, manufacturers, operators, and government agencieshave joined the network to develop noise reduction methods atthe source, quiet traffic routes, and operational procedures; torecommend new noise rules and standards; and to improve traf-fic management and control. Beneficiaries will be residents af-fected by traffic as well as industry, which, by achieving specificknowledge in noise abatement technology, will gain a competi-tive advantage. Current activities: - Low-noise road traffic - tire-road interaction, noise at expansion joints - Low-noise trains andtracks - wheel-rail interaction, propulsion noise - Low-noise trans-port aircraft - engine and airframe noise - Common technologiesand methodologies - noise source location, propagation, and im-mission prognoses. A special feature is the inclusion of researchon the effects of noise on humans to formulate reliable specificnoise criteria and limit values and to suggest effective ways tolower the effects from noise exposure. Although some activitiesextend to 2006, first results have already been achieved.


Protecting people against transportation noise - overviewover the section ’Noise effects’ within the ’Research NetworkQuiet Traffic’Barbara GriefahnInstitut für Arbeisphysiologie an der Universität DortmundWithin the Research Network ’Quiet Traffic’ the section ’Noise Ef-fects’ a variable number of partners focus their activities on thesolution of four problems: 1) Diurnally varying noise sensitivity.One partner studies residents either exposed to rail or to roadnoise. Noise levels and acute annoyance are recorded duringthe day to quantify the temporal responsiveness. Another part-ner determines the reactions to both noises during sleep. Theresults are applicable for traffic management. 2) Assessmentof frequency spectra. Noise attenuation reduces the level butalters the spectra towards lower frequencies and the temporalstructure towards intermittency which both cause stronger effectseven during deep sleep. Five partners evaluate the significanceof lower frequencies for communication, performance, and sleep.The results are useful for the construction of vehicles. 3) Assess-ment of noise sources. All partners study the effects of rail and ofroad noise on various psychophysiological functions. The com-parison reveals whether the rail bonus is valid for various activi-ties. 4) Assessment of combined noise sources: It is as yet notpossible to evaluate noise emitted from more than one source.


Four partners study annoyance while combining systematicallyvarious road and rail noises and will develop an appropriate pre-diction model.


Multidimensional scaling of road and railway noise in a 5.1-surround situationRudolf BispingSASS acoustic research & design GmbHThe effect of combined road and railway noises on the humanlistener is one of the topics of the BMBF-project Leiser Verkehr.Currently a joint study is performed by three laboratories (IfADo,SASS, Universität Eichstätt-Ingolstadt) to find out wether thecombination of these noise has some specific interactive effecton the listener or not. Beside annoyance other perceptual cuessuch as timbre, powerfulness, impulsiveness, etc., are assumedto be relevant, too. For this reason subjects where asked to scalethese attributes using a multidimensional categorical technique.The experimental noises were presented in an ITU 5.1-surroundsituation which proved to reproduce quite naturally the quality ofthe original sources. Factor analysis of the data showed that in-deed the perception of the noises is related to a hierarchicallyorganized pattern of several cues rather than just on annoyance.The data not only help to better understand the human percep-tion of traffic sounds and to improve the scaling procedure in thecurrent joint study but are used as a psychometric guideline forthe set up of a systematic library of road and railway noises, too.


Evaluation of traffic noise by quality of speech communica-tionCharlotte A. Sust, Hans Lazarus, Rita Steckel, Marko KulkaABoVe GmbHEvaluation of traffic noise by quality of speech communicationby Ch. A. Sust1, H. Lazarus2, R. Steckel2, M. Kulka2 1AboveGmbH; 2BAuA (Federal Institute of Occupational Safety andHealth) Speech is the most important medium of communica-tion. Disturbing communication by noise influ-ences the qual-ity of dwellings, leisure areas, and workplaces. The quality ofspeech communica-tion is mainly influenced by speech intelligi-bility, which is used as an important instrument for dis-criminatingthe effects of different noises. High signal-to-noise-ratios result ina relative high speech intelligibility which is defined with definedspeech material as a percentage of recognised speech items (0to 100 %). But a high speech intelligibility does not mean auto-matically a high quality of speech communication, which is also


influenced f.e. by necessity of concentration, of coping strate-gies, etc. In two experiments speech communication will be sim-ulated under defined conditions, which al-lows an effective eval-uation of different - concerning frequency and time structure -traffic noises. That means defined speech material - monosylla-bles and semantically contextfree, but grammati-call correct sen-tences - has been recorded from different speakers (male, fe-male, native and non-native speakers) and is presented undersix different signal-to-noise-ratios (from -15 to +20 dB) of trafficnoises to subjects, who have to repeat the monosyllables andthe sentences. After present-ing three items subjects have toevaluate the quality with a rating scale which includes aspectsof subjective speech intelligibility, concentration, annoyance andcoping strategies. Results of the first experiments, where noisesvarying in frequency (RR, road and train traffic noise) are used,are presented.


Detrimental Effects of Traffic Noise on Basic Cognitive Per-formance in AdultsAlexandra Schmid, Jürgen HellbrückCatholic University of Eichstaett - IngolstadtNoise is one of the most serious environmental problems. Es-pecially traffic noise has been permanently increasing in the lastdecade, and is expected to grow dramatically in the near future.Particularly at working places such as bureaus or schools, whichare situated nearby highly frequented routes, traffic noise is be-coming more and more a reason for complaints. The results ofpreliminary experiments investigating basic cognitive functions,which are important in mental work, like attention, encoding ormemory, are reported. These cognitive functions show differen-tial sensitivity toward certain aspects of traffic noise, especially itsloudness and spectral-temporal structure. The findings are inter-preted in relation to the well examined influence of speech-basednoise on such tasks. So far, it can be shown that the crucial pa-rameter of traffic noise contrary to background speech is first ofall its sound pressure level, but also its temporal structure. Ad-ditionally, the impact of traffic noise depends on the nature ofthe cognitive requirements. Especially tasks that demand morecentral executive functions seem to be sensitive for interferencescaused by traffic noise. These results are discussed with respectto deductions for noise abatement.



”Leiser Verkehr” (Quiet Traffic), Project 2222: Effects of traf-fic noise on speech intelligibility and cognitive performancein children, Part 1: Effects of different kinds of traffic noiseon reading and attention performance in elementary schoolchildrenHelga Sukowski, Maria Klatte, Markus Meis, August SchickUniversität Oldenburg, Institut für Psychologie, Abteilung Umweltund KulturIn the context of the sub-project ”Effects of traffic noise on speechintelligibility and cognitive performance in children” the first testmodule examined attention performance (arithmetic test) andreading performance (reading test) in children under the influ-ence of traffic noise. In addition, the perceived annoyance due topresented noise stimuli was surveyed. The implemented soundsvaried in traffic density and frequency spectrum. A total of 103children from elementary schools in Oldenburg with ages rang-ing from 8-10 years at the time of participation took part in theexperiment. The results from the arithmetic test show a generalnegative influence of the noise conditions compared to the con-trol condition as well as significant differences between particularnoise conditions. In both the arithmetic and reading tests, neg-ative effects due to traffic noise were especially detected in chil-dren with high performance levels. An analysis of the judgmentson annoyance primarily revealed an influence of traffic density. Intotal, negative effects of general noise conditions as well as ofparticular noise stimuli were confirmed. The results additionallyindicate that the influence of noise stimuli cannot only be pre-dicted by acoustical parameters. Moreover, other factors such asindividual performance ability also influence whether and to whatextent an effect due to noise is detectable.


”Leiser Verkehr” (Quiet Traffic), Project 2222: Effects of traf-fic noise on speech intelligibility and cognitive performancein children, Part 2: Effects of different kinds of traffic noiseon children’s speech perception and phonological short-term memoryMaria Klatte, Helga Sukowski, Markus Meis, August SchickUniversität Oldenburg, Institut für Psychologie, Abteilung Umweltund KulturThe ability to analyze, store and process heard speech plays afundamental role in social and cognitive development. Since chil-dren have much more difficulties to understand speech in noisethan adults, noise reduction should be a primary goal in order to


achieve acoustical environments supportive for children’s learn-ing. In a current study, we investigate the effects of traffic andspeech noises on performance in listening tasks in children agedsix to seven years. The tasks include phoneme discrimination,phonological short-term memory, and sentence comprehension.The traffic sounds vary with respect to temporal and spectralcharacteristics. The aim of this study is (a) to explore the effectsof moderate-level environmental noise on children’s learning and(b) to explore which qualities of traffic sounds affect the disrup-tion of children’s speech perception. Such findings could providereasonable guidelines for the technical development of low-noisemeans of transport.


Acute Annoyance caused by Noise emitted from Rail andRoad TrafficEdna Leue, Martin Schütte, Barbara GriefahnInstitute for Occupational PhysiologyObjectives: The study aims at the determination of dose-response-curves for separately occurring train and road trafficnoise in the laboratory. It is supposed that acute annoyance de-pends on the particular activity a person actually performs. Themain question to be answered is, how the dose-response rela-tion is influenced by actually exerted activity. Method: 24 healthymale and female subjects, 20 to 30 years of age listen to a totalof 16 sounds while sitting in a sound proof room. Each soundlasts 3 minutes, the sound pressure levels of road and rail trafficnoise are varied from 40 to 82 dB (A) in steps of 6 db(A). Thesubjects are requested to imagine to be at home. Following eachpresentation they have to rate the resulting acute annoyance aswell as loudness, pitch, dynamics, impulsiveness and pleasant-ness. Additionally, they rate the annoyance that they expect whileperforming six different home activities. Results: Annoyance ob-tained for the condition ”to be at home” will be compared withannoyance supposed in case of different home activities. Thestudy is in progress and will be finished at the end of the year2003.


Statistical modelling of exposure-response relationships inthe analysis of multiple transportation noisesSonja Kuhnt, Christoph SchürmannFachbereich StatistikTransportation noise from diverse sources results in different sub-jectively felt loudness and annoyance. To assess this relationshipquantitatively one wants to have exposure-response models. We


consider data from experiments, which expose subjects to mul-tiple transportation noises consisting of different levels of roadand rail traffic noise. When analysing the effect of noises, ratingscales are often used such that subjects can record their individ-ual perceptions quite precisely. In these cases the assumption ofa Normal distribution for the ratings underlying the classical lin-ear model is usually not appropriate. So-called generalised linearmodels extend the linear model in two ways: data are not neces-sarily assumed to be normally distributed but have a distributionfrom an exponential family and the mean is not necessarily mod-elled as a linear combination of certain covariates but some func-tion of the mean is. We show how this model class can be usedto derive a prediction model for annoyance resulting from multipletransportation noise. We use a dataset from an experimental set-up where subjects have had to accomplish grammatical reason-ing tasks under certain surrounding noise scenarios. The effectof noise on the subject is measured mainly by the subjectivelyfelt annoyance and loudness. Further covariates like daytime ofexposure, sex, laboratory and difficulty of the task are also con-sidered.


Sleep disturbances caused by transportation noise - part 1:alterations on the polysomnogramAnke Marks, Barbara GriefahnInstitut für Arbeisphysiologie an der Universität Dortmund,Leiser Verkehr” (Quiet Traffic), Project 2311: Sleep disturbancescaused by transportation noise - part 1: alterations on thepolysomnogram Anke Marks & Barbara Griefahn Institute for Oc-cupational Physiology at the University of Dortmund Objectives:Noises from road, rail, and air traffic are compared concerningsleep disturbances and after effects to derive adequate ”Bonus-Malus”-regulations. Methods: 32 healthy and normal hearing stu-dents (16 male, 16 female, 18 - 30 years) sleep ever 4 nightsof three consecutive weeks in the laboratory while exposed tothe randomly presented noises. Each set of four nights con-sists of a control night and 3 nights with Lmax of 62, 68, and74 dB(A). The same Leq for the 3 noises is achieved by varyingthe number of events. Dependent variables are the polysomno-gram (EEG, EOG, EMG, ECG), subjective assessment, and per-formance (switch task, go/no-go task, random generation of num-bers). Results: Concerning the polysomnogram, latency, totalsleep time, total time spent awake and in deep sleep were evalu-ated. First analyses of few subjects revealed that irrespective ofthe type of noise the time awake increases and deep sleep de-creases with the sound pressure level. The strongest difference


exists between the quiet condition (32 dB(A)) and the maximumnoise load (74 dB(A)). Concerning noise quality, the strongesteffects in terms of increased time awake were evoked by rail traf-fic noise. A more detailed evaluation will be presented at thecongress.


Sleep disturbance by traffic noise: after-effects on brain ac-tivitySergei Schapkin, Barbara GriefahnInstitute for Occupational PhysiologyThis study examined the influence of sleep disturbances causedby traffic noise on inhibitory processes underlying the action plan-ning and implementing. Fourteen undergraduates completedboth simple and complex Go/Nogo tasks to visual word stimuliafter sleep in quiet and after sleep under the influence of aircraftand road traffic noise with Lmax = 74 dB(A). The difference inevent-related brain potentials (ERPs) between Nogo and Go tri-als served as an index of inhibition. After quiet nights, the N2dand P3d components with a maximum over fronto-central brainareas were smaller in amplitude and longer in latency in complexthan in simple task, which suggests that they reflect the amount ofresources available for inhibition of an intended action and hencefor effective regulation of behaviour. In contrast, after noisy nightsthe clear-cut decrease of the N2d and P3d amplitudes and (to alesser extent) prolonged latencies were obtained. This effect wasgreater in the complex task than in the simple one and after sleepdisturbance induced by road traffic noise than by aircraft noise.The result suggest that traffic noise can exert its negative effecton brain processes indirectly, through shortening of cognitive re-sources by sleep disturbance.


Low Noise Road Traffic - Results from test site B56Wolfram BartolomaeusBundesanstalt für StraßenwesenThe project ”low noise road traffic” was part of the integratedproject ”low noise traffic”. It was finished for the most part endof 2003. During the project together with our 15 partners fromindustry, institutes and universities we developed new road sur-faces, new tires, a new wheel housing and new bridge crossings.On our test site, B56 near Düren, 10 different surfaces were build.Results from both controlled pass-by and statistical pass-by mea-surements over two years from these sections are shown.


Mo. 14:30 Arp 3 Localization of normal hearing . . .

Binaural rendering assessment in the context of augmentedrealityOlivier Warusfel, Olivier Delerue, Isabelle Viaud-DelmonIRCAMThe paper presents recent work undertaken on binaural render-ing in the context of the European project LISTEN, dedicatedto augmented reality (AR) and museum applications. Thanksto wireless technology applied to audio transmission and track-ing systems, binaural synthesis, up to now confined to labo-ratory contexts, may be applied to create large scale immer-sive and interactive virtual sound scenes. In these applications,the visitor, equipped with motion-tracked wireless headphones,explores a real space seamlessly augmented by an interactiveaudio content. The virtual sound scene, composed of soundsources disseminated in the space and of associated room ef-fects, is rendered using binaural synthesis, the only techniqueallowing fully controlled localization cues. The paper reminds thedifferent implementation approaches for binaural rendering andthe remaining issues often commented in the litterature, such asthe front-back localization ambiguity and the need for an indi-vidual morphological adaptation. However, the introduction ofthe 3D sound modality in augmented environments highlightsthe need for a better understanding of multi-sensorial integrationmechanisms, since the context involves user’s navigation andperception-action mechanisms linked to auditory versus idiotheticinteractions. Moreover, augmented reality also allows the use ofnon physical or realistic laws, when modelling distance effects,auditory perception field or room reflexions. Therefore, conven-tional localization performance tests, usually applied for assess-ing binaural rendering quality, should be replaced in a multimodalscheme focusing on the congruence of the virtual world and onthe user’s ability to fulfil a navigation task or to build a cognitivespatial map of the proposed world.


Localization of Auditory Sources in Virtual RealityIsabelle Viaud-Delmon, Ludivine Sarlat, Olivier WarusfelCNRS UMR7593Virtual reality (VR) represents a set of computer technologies,which allow users to interact with a three-dimensional, computer-generated environment in real time. VR is starting to be used inpsychophysics experiments as well as in psychological therapyaround the world. VR provides a way to immerse a user in anenvironment in which the interaction between different sensory


modalities can be controlled. Therefore VR represents an inter-esting tool to study the integration of space-related multisensoryinformation in human and its disorders. Incorporating real-timeupdated 3-D sound to virtual reality technologies addresses sev-eral issues. If there seems to be a consensus on the fact that’presence’ is improved by 3-D sound, little is known about howan auditory virtual environment (VE) should be designed so that itdoes not interfere with the visual VE. It is well known that discrep-ancies in the location of synchronized auditory and visual eventscan lead to mislocalizations of the auditory source, so-called ven-triloquism. In two experiments, we tested whether such cross-modal influences on auditory localization could be observed afteran immersion in a VE. Auditory stimuli were presented via head-phones (HRTFs) and were presented in synchrony with virtualvisual events. We observed that the association of virtual audi-tory and visual stimuli could lead to a ’complete’ remapping ofauditory space, including stimulus locations not presented duringthe VR immersion. It is therefore possible to induce a ventrilo-quist effect with VR, which can not be interpreted in terms of asimple visual biasing of auditory localization.


Learning to Judge Distance of Nearby Sounds in Reverber-ant and Anechoic EnvironmentsNorbert Kopco, Matt Schoolmaster, Barbara Shinn-CunninghamBoston University Hearing Research CenterPrevious studies have shown that accuracy of distance judg-ments for nearby sources improves over time when the listeneris in a reverberant environment, but not in an anechoic space.The improvement observed in rooms may be the result of thelistener learning (through experience) how to interpret reverbera-tion cues and map these cues to different distances in a particularroom. The present study evaluates whether such ”room learning”is disrupted when reverberation cues vary over the course of theexperiment. Results of two auditory distance perception exper-iments are reported. In the first study, perceived distance wasmeasured for listeners whose position in a real room was variedfrom session to session. In the second study, distance percep-tion was studied using virtual auditory space (VAS) techniquesto simulate sounds for different listener locations in a reverberantroom and in anechoic space. In the real room, listeners appearedto get better at judging source distance despite the fact that theirlocation in the room varied from session to session. However,in the VAS study, intermingling sounds simulated in a room withsounds simulated in anechoic space led to a dramatic reductionin performance overall as well as a reduction in the amount of


improvement observed with experience. In the limit, when thesimulated room was varied on a trial-by-trial basis, no learningwas observed. These results suggest that listeners can gener-alize ”room learning” across different listener locations within asingle room, but not across dramatically different acoustic envi-ronments.


Modeling the Precedence Effect for Noise Bursts of DifferentDurationsJonas Braasch, Jens BlauertInstitut für Kommunikationsakustik (Web: www.rub.de/ika)Recently, a number of binaural models have been applied to ex-plain the precedence effect for experiments using click pairs with-out the need of contralateral-inhibition elements as was proposedby Lindemann in 1986. These findings raised the question of towhat extent those types of models are able to explain experi-ments for lead-lag pairs with longer durations. The simulation re-vealed that models which simulate the precedence effect by usingthe special characteristics of the auditory periphery (Hartung andTrahiotis, 2001) or by focusing on the spectral-dominance region(Tollin, 1998) fail when stimuli of longer duration than clicks areused, while a modified Lindemann model still shows satisfactoryresults. In principle, the modification consisted of alternating thecombined algorithm to process interaural level differences andinteraural time differences into two separate ones. In the modelsimulation, it was unnecessary to consider cross-frequency-bandinteraction like the second coincidence weighting of Stern et al.(1988), and it was sufficient to estimate the average of the out-puts of the frequency bands involved. However in order to simu-late the data for the ongoing (non-impulsive) stimuli, the degreeof inhibition, which was originally adjusted to simulate the prece-dence effect for click pairs, had to be increased considerably.These findings indicate that the degree of inhibition increases dy-namically with the exposure time of the stimulus.


Sensitivity to Interaural Time Delay in Stimulus Fine Struc-ture and Envelope of Bilateral Cochlear Implant ListenersBernhard Laback, Piotr Majdak, Wolf-Dieter BaumgartnerAcoustics Research Institute, Austrian Academy of SciencesRecent studies on the sensitivity of bilateral cochlear implant (CI)listeners to interaural time delay revealed JNDs in the order of100 µs. There are indications that sensitivity is restricted to stim-uli containing low rate signal information in either the carrier orthe envelope. This has been inferred from JNDs for ITD applied


either to the entire stimulus (interaural waveform delay, IWD) orto the envelope only (interaural envelope delay, IED) [R. van Hoe-sel and R. Tyler, 2003]. This study investigates the sensitivity ofbilateral CI listeners to IWD, IED and, as a newly tested condi-tion, delay in the fine-structure only (interaural fine-structure de-lay, IFSD), as a function of pulse rate. Two different stimuli aretested: stimulus A is a sequence of four equal-amplitude pulses.Sensitivity to IWD, IED and IFSD is tested by interaurally delay-ing all 4 pulses, pulses 1+4 only, or pulses 2+3 only, respectively.Stimulus B is a pulse sequence shaped with a trapezoid function.Here, IWD, IED and IFSD refer to an interaural delay in the entirestimulus, the envelope only or the pulse timing only, respectively.The experiments are also performed with normal hearing sub-jects listening to simulations of CI stimulation. With these exper-iments we hope to get more insight into the relative potencies ofinteraural envelope- and fine-structure delay at different electricalpulse rates. Moreover, the results should provide information onthe relevance of interaural synchronization in pulse timing. Re-sults of these experiments, which are currently underway, will bepresented.


Localization cues with bilateral cochlear implants investi-gated in virtual space - a case studyBernhard Seeber, Hugo FastlAG Technische Akustik, MMK, now at: Dept. of Psychology, UCBerkeley, Berkeley, CA 94720-1650, USACochlear implants stimulate spiral ganglion cells in few, wide ar-eas using discrete, amplitude-quantized pulses. This results inreduced spectral, temporal, and amplitude resolution. Neverthe-less, several studies could show outstanding localization abilitywith selected bilateral cochlear implant subjects. A previous free-field study showed that interaural time differences could not beevaluated for localization with low-frequency carriers (Seeber etal., DAGA 2003). As the relative weighting of interaural tem-poral and level cues for localization can not be tested for high-frequency carriers in the free-field, a study using virtual soundpresentation was conducted. Interaural level cues (ILDs) werecalculated from test stimuli, which incorporated the compressivepre-processing of the cochlear implant. Interaural temporal cues(ITDs) were deduced from directional transfer functions of thespeech processor when being placed on a head. The ILD andITD cues of the test stimuli were then independently modified. Alocalization test using these modified virtual stimuli showed highspacial sensitivity to changes in ILDs, but no or small sensitivityto ITD changes, even for high frequency carriers. It can thus be


followed that interaural temporal cues are not used by this sub-ject for localization. In opposite to normal hearing, localizationis entirely based on monaural spectral cues and interaural levelcues for our cochlear implant subject.

Mo. 16:50 Arp 3 Microphones and loudspeakers

Design refinement of high order ambisonics microphones -Experiments with a 4th order prototypeJérôme Daniel, Sébastien MoreauFrance Télécom R&DAmbisonics is a very flexible sound spatialisation technologybased on the spherical harmonic decomposition of a sound field.It has known an increasing interest during the past years thanksto studies that have extended the theory (and to a less extent, itsapplication) from first to higher order. This paper deals with thetheory, design and implementation of high order ambisonic micro-phones. High order ambisonic pickup is a technology based onthe spherical harmonic decomposition of a sound field. The goalis to record the spherical harmonic components that describe thesound field at a chosen point of the referential and in the vicinityof it. The area of reproduction depends on the numbers of con-sidered components and signals frequency. The estimation ofthe spherical harmonic components is in fact distorted due to thealiasing effect that appears when a finite number of sensors isused. The importance of this artefact depends on both sphericalarray radius (and thus the angular gap between sensors) and fre-quency. The implementation of an ambisonic microphone comesup against another problem. If we consider the near field record-ing, the equalization has an infinite bass amplification for low fre-quencies and high spherical harmonics components. Compro-mises must be introduced to make practicable application possi-ble. A prototype of a high order ambisonic microphone capableof recording the sound field up to the 4th order has been realized.This prototype consists of 32 sensors arranged on the surface ofa rigid sphere associated with a signal-processing unit.


An Alternative Concept for the Realization of a Digital Con-denser Microphone with high-range DynamcicsRoland Müller, Peter HolsteinSINUS Messtechnik GmbHA concept has been recently presented for high-frequency con-denser microphones (DAGA 2003. Especially, it is appropriatefor high-quality microphones for measurement purposes. In thisconnection, the capacity of the microphone capsule dominatesthe frequency behaviour of a LC-generator. The non-linearity,


which is a results of Thomson’s relationship, can be compen-sated to a large extent. This results in large range of dynamics.In this contribution, an approach will be discussed for adequatedemodulation and digitization. The proposed procedure are char-acterized by low noise and extremely small non-linear distortions,as well. Simulations and experimental results are compared.


Study of a PVDF dome shaped loudspeakerBruno GazengelLAUMThis work studies the acoustic radiation of a dome shaped PVDFloudspeaker. The PVDF loudspeaker consists of a circular PVDFthin film, clamped around, dome shaped by means of a staticpressure which is applied at the back. A time variable voltageapplied between the two faces of the film enables to produce aacoustic pressure by means of the piezoelectric effect. The firstpart of the study focuses on the static behaviour of the speaker.The static deformation is calculated using models found in lit-erature and is measured by means of a displacement sensor.Results enable to estimate the Young modulus of the PVDF ma-terial used in the experiment. The second part focuses on the dy-namic behaviour of the speaker. At first, analytical models foundin the literature are used for predicting the acoustic pressure radi-ated. Secondly, a finite elements model is used for calculating theacoustic pressure radiated in the near field of the speaker. Finally,an experiment is conducted for measuring the pressure responseof the speaker. Results show that results obtained by means offinite elements and experimental results agree well. However,the analytical model does not enable to estimate the acoustic ra-diated pressure. This difference is explained by the fact that theanalytical model does not take into account the coupling betweenthe film and the air.


Electro acoustic coupling in closed spacePierre-Jean ReneEcole Polytechnique Fédérale de LausanneThe design of loudspeaker systems is usually undertaken underthe assumption that load impedance is a radiation impedanceinto 2 or 4p sr. This is not valid when the wave lengths at the fre-quencies used by the loudspeaker are of the same order of mag-nitude as the dimensions of confined space, for example for thelow-frequency sounds in a room, control room, or in a technicalvolume in which active noise control is being carried out (enginenacelle), etc. The loudspeaker cannot be compared any more to


a source of constant volume throughput: the flow depends notonly on the system excitation but also on the source and loadimpedances. This requires better modelling of the electro acous-tic coupling between the loudspeaker and room in which it ra-diates, particularly below the Schroeder frequency, where thereare no or only few excited modes. The calculation of the transferfunction between the voltage at loudspeaker connectors and theacoustic pressure at any point of the closed space can be madeusing this model.


Characterisation of Non-LinearitiesDelphine BardEcole Polytechnique Fédérale de LausanneCharacterisation of non-linearities The characterisation of aweakly non-linear electroacoustic device with classical methodsof measurement (THD, intermodulation) does not illustrate thenon-linearities themselves, but only some of their effects. De-vice linearisation can be achieved by applying the inverse non-linearity upstream of the device, under the condition that the non-linearity law is known in detail. This paper presents the first stageof transducer non-linearity compensation, namely an experimen-tal method of weak non-linearity characterisation, based on theVolterra series and the analysis of the device response to ’mul-titone’ excitation signals. A careful choice of the number, mag-nitude and phase of the excitation components allows an easyand effective extraction of Volterra kernels at their different or-ders. When expressed in the frequency domain, the latter consti-tute a generalisation of transfer functions at orders greater thanone. The algorithm corresponding to the presented method hasbeen developed and implemented as software, handling both thegeneration of excitation signals and the analysis of their responsein terms of Volterra kernels, with the support of ’.wav’ files. It isthereby possible to rebuild the response of the non-linear systemfrom the kernels and to compare it to experimental results.


Realization of a Dynamic Equalizer for Audio Signals usingLinear Phase IIR Digital FiltersDieter Leckschat, Oliver LuedeckeUniversity of Applied SciencesEqualizers with signal-dependant filter characteristics have awide application field in audio restauration, sound reinforcement,mastering, sound design and others. Moreover it is desirable formany applications that the filters are phase linear. In the litera-ture a method has been introduced to realize phase linear digital


filters of the IIR type using local time reversal. We report on twoimplementations of an algorithm which supports the linear phaseIIR method and the real time morphing of filter coefficients in de-pendance of the signal level. One solution works as a nativeplug-in which can easily be integrated in most audio process-ing programs while the other one is a 48-Bit DSP software usedon dedicated signal processing cards. - Processing power andmemory considerations will be discussed as well as performanceaspects.

Tu. 8:30 Schweitzer Car acoustics II

Road Noise Analysis Using A Binaural Time Domain Ap-proachChristian Nettelbeck, Daniel Riemann, Philipp SellerbeckHEAD acoustics GmbHAs the noise from the power train is continuously reduced, roadand tire induced airborne and structure-borne noise shares be-come more and more important for the overall sound quality. Twoindependent road noise mechanisms have to be taken into ac-count: tire noise on plain or coarse road and noise from singlebumps. Starting from a binaural vehicle interior noise recording,a method based on multiple coherence analysis is introducedthat enables the user to distinguish between the noise sharesof single axis, wheels or even between airborne and structure-borne noise contributions. Due to the fact that the method worksin the time domain it includes the advantage to binaurally lis-ten to single contributions. Furthermore, it is possible to verifythe influence of component transfer behaviour or vibroacousticbody transfer functions on the single noise contributions, whilesource signals and transfer paths can be addressed individu-ally. The auralization of synthetic modifications of single inputsignals and/or transfer paths provides helpful information for trou-bleshooting and sound design.


Binaural Auralisation of Vibrating Surfaces - Laser ScanningVibrometry Combined with Binaural Transfer Path AnalysisOliver Wolff, Sandro Guidati, Roland Sottek, Heinrich StegerHEAD acoustics GmbHLaser Scanning Vibrometry has become a well-established work-ing tool for vibration analysis in different areas of automotive in-dustry and research. Apart from statics and strength a lot of ap-plications are increasingly concerned with acoustics. The knowl-edge of vibration behaviour alone is usually not sufficient to fullydescribe the acoustical behaviour, since the sound radiation fac-tor, the transmission of the sound to the drivers’s ears (airborne


transfer functions) as well as the structural pattern of the sound it-self (psychoacoustic perception) have not been adequately takeninto account so far. A new method is presented combining laserscanning vibrometer measurements with binaural transfer pathanalysis. Airborne noise transfer functions between driver’s earsand the vibrating surfaces are measured with a binaural soundsource by making use of the reciprocity principle. Thus visualrepresentation of structural vibrations is not limited to e.g. theamplitude of a certain vibration, but is numerically weighted withthe binaural airborne noise transfer function instead. This newtype of representation is a measure for the acoustic relevance ofthe structure and points to single areas responsible for the noiseat the driver’s ears. This procedure allows the binaural auralisa-tion of acoustical contributions from different areas of a vibratingstructure. Measured acoustic transfer functions can also be usedas filters for time data visualisation. This provides additional ac-cess to non-stationary investigations as well (e.g. run-ups). Ex-perimental results gained from a model structure that has beenbuilt up for investigation purposes as well as first results on a testvehicle will be presented.


Binaural Panel Noise Contribution Analysis - An Alternativeto the Conventional Window MethodOliver Wolff, Roland SottekHEAD acoustics GmbHWhen designing the interior noise of a vehicle it is often inter-esting to know the noise contributions from single surface areasto the total interior noise. The conventional ”window method”,sometimes also called ”subtractive procedure”, requires the par-tial or full encapsulation of the passenger compartment with aproper sound insulation package. This vehicle condition servesas a reference. The sound level of the reference condition is re-lated to the measured sound level for sound insulation packageswhere insulation material has been selectively removed from theindividual surfaces of interest (windows). The level difference isused as a measure for the acoustical surface contribution to thetotal sound level. Unfortunately, test drives on roads are hard torealise due to safety reasons. The weight of the sound insulationpackage alters the structure of the vehicle and the absorption be-haviour of the cabin is changed, too. Additionally, the preparationof the sound insulation package is generally time consuming andexpensive. However, HEAD acoustics is able to present a newprocedure, the binaural panel noise contribution analysis. By us-ing a special sensor array which is applied to the surface under


investigation, it is possible to perform measurements while driv-ing on the road. Vehicle structure and absorption behaviour arenot changed by the array. In addition to significant time- and cost-saving-effects, this new procedure offers a wide range of analysispossibilities. Room acoustics is taken into account and enablesusers to listen binaurally to the noise contributions of individualsurface areas. The described procedure has been successfullytested on several vehicles.


Psychoacoustic investigation on sport sound of automotivetailpipe noiseJan Krüger, Frank Castor, Alexander MüllerJ. Eberspächer GmbH & Co. KGIn addition to technical and economical aspects, the emotionalcomponent of modern cars gains more and more importance.The sound of the exhaust system is one of these emotional com-ponents. Due to the legislative limitation of the pass-by-noiselevel, it is not possible to emphasise the sportiness by simplyincreasing the SPL. Therefore, the first part of this investiga-tion dealt with the characterisation of sport sound of automotivetailpipe at comparable noise levels. For this purpose, physicalmeasurement categories and psychoacoustic parameters werecompared with subjective evaluations. In the course of a JuryEvaluation, 101 test persons assessed several Artificial HeadRecordings of different tailpipe noises. Furthermore, some ofthe original recordings were modified according to rules of otherworks published ear-lier on. Five pairs of adjectives were usedto describe the subjective sound impres-sion. These five pairsof adjectives could be summarised in the two factors sportinessand comfort by means of the statistical method of factor analysis.In the second part, the influence of individual properties suchas age, sex, annual kilometres travelled on the subjective soundevaluation was determined.


Acoustic Quality Control of Drum Brake ShoesMichael Haverkamp, Norbert KoopmannFord Werke AG KölnRecent investigations of brake noise phenomena show that natu-ral frequencies and damping of brake components play an impor-tant role regarding the propensity of noise excitation. While worksare on-going to include requirements of those parameters into in-ternational standardization (e.g. ISO) of disc brakes, there is lackof knowledge regarding drum brake noise. Torsional modes ofdrum brake shoes are a main contributor to squeal phenomena,


because they provide coupling of backing-plate bending modesto axial drum resonances. Therefore natural frequencies, damp-ing and variability of physical properties of the shoes are main pa-rameters, which have to be assessed. Vehicle tests have shownthat in various cases a strong increase of the torsional stiffnessof drum brake shoes can eliminate squeal phenomena. First, thepresentation provides an overview of methods appropriate for ex-citation and measurement of the vibrational modes. Secondly, aquick test is recommended that avoids complicated fixture of ex-citing structures and measurement pickups. This method workscost-efficiently and allows fully automated operation. Test resultsare presented and compared with those of various methods ofvibrational analysis.

Tu. 10:10 Schweitzer Car acoustics IISound quality design by passive measures in the underbodyand the closer engine areaDimitrios Patsouras, Klaus Pfaffelhuber, Christine PatsourasAKsys GmbHSeveral passive measures in a vehicles’ underbody area (encap-sulation with various membrane absorbers or microperforated ab-sorbers) as well as in the motor compartment were realized. Therecorded outdoor idling noises of the vehicle equipped with thosedifferent passive measures were presented to subjects in psy-choacoustic experiments. The subjects’ judgments allowed todraw clear conclusions about the efficiency and the quality of therespective absorbing system and showed thus the large potentialreachable by passive measures in the engine compartment.

Tu. 14:50 Schweitzer Car acoustics IIISubjective and objective characterisation of tonal compo-nents in tyre/road noiseSandra Buss, Reinhard WeberCarl von Ossietzky Universität OldenburgAn important factor for the generation of tyre/road noise is thegeometry of the tread pattern. The pattern noise is a tonal com-ponent of the tyre/road noise with speed dependent frequency.A perceivable tyre/road noise leads to a decreased quality ratingin a subjective evaluation of tyre/road noise. In order to find anobjective measure for the subjectively perceived pattern noise,tyre/road noises are evaluated in a paired comparison test. Theset of tyre road noises consists of one tyre/road noise and mod-ifications of this signal with systematically varied spectra. Thesubjective evaluation of pattern noise can be referred to objectiveparameters calculated from the signal. Also an aurally adequatesignal analysis is performed and compared to the subjective eval-uation of the tyre/road noises.


Tu. 15:10 Schweitzer Car acoustics IIIThe effect of Road Absorption on Tyre-Road Horn effectFabienne Anfosso-LedeeLCPCHorn effect is an amplification phenomenon of the tyre-road noisegenerated at the contact patch, due to multiple reflections be-tween the tyre belt and the road surface. This effect can be dras-tically reduced when the pavement is sound absorbing, which isthe case for porous pavements. A 2D BEM model was used topredict this effect in which a non local absorption condition wasintroduced to take into account the effect of porous road surfaces.An experimental validation was made on porous and non-porousreal pavements, using the principle of reciprocity. The 2D tyrewas simulated by a long concrete tube. The impulse responsewas measured between a point source located in front of thetube and a microphone located flush on the tube surface, nearthe contact with the road surface. The amplification effect wasevaluated with reference to semi-free field condition above theroad surface. In parallel, the amplification was calculated. Thephysical parameters of the porous road introduced in the modelwere deduced from in situ measurements of sound absorption.A good agreement was found between measurements and pre-dictions, both for reflecting and absorbing road surfaces. Subse-quently, an estimation of the influence of the horn effect on closeproximity tyre-road noise measurements is proposed. The differ-ence observed between the noise radiated behind and sidewaysof the tyre can be explained by this horn effect.

Tu. 15:30 Schweitzer Car acoustics IIIVibration Field on a rolling tyre - results from a simulationmodelWolfgang Kropp, Ulrich SaemannDepartment of Applied AcousticsTyre road noise is the dominant source for traffic noise at driv-ing speeds above 30 km/h. In order to achieve a substantial re-duction of tyre/road noise a sound understanding of the noisegeneration mechanisms is required. At the Department of Ap-plied Acoustics, Chalmers University of Technology, a simulationmodel for tyre/road noise generation is under development. Withthis model it is possible to calculate the vibration field on the tyrestructure for a tyre rolling as a function of tyre properties such astyre design, tread pattern and road parameters (i.e. road texture).The simulation model is used to predict the vibration field for dif-ferent tyres at different rolling speeds. A qualitative comparisonis made between simulation results and results from near fieldholography.


Tu. 15:50 Schweitzer Car acoustics III

Road impedance optimisation using an efficient 2D modelfor the tyre radiationF-X. BecotINRETS - LTE (Transport and Environment Laboratory)Because of the extension of the transportation network, an in-creasing number of people declare to be annoyed by traffic noise.Under normal driving conditions, the main contribution to overallnoise levels is the noise induced by the tyre / road contact. Inorder to control the noise source and to contribute to the noisereduction offered by noise barriers for instance, accurate numeri-cal tools are needed for the prediction of tyre / road noise includ-ing the effect of the pavement absorption. The work presentedin this paper contributes to this effort by proposing a model forthe tyre radiation over arbitrary impedance surfaces. This two-dimensional model, developed on the basis of the equivalentsources method, has been validated by comparisons with mea-surements of horn effect amplifications over arbitrary impedancesurfaces. Due to its numerical efficiency compared to 3D models,it is an adapted tool for performing parametrical studies concern-ing the tyre / road interface properties. In particular, the modelcan be used to predict the optimal value of the surface acousticalimpedance. Results show that this latter value is very sensitive toa number of parameters, among others the frequency of interest,the position of the noise source inside the horn and the length ofthe contact zone. However, in all cases, the model predicts animpedance value which is physically realisable. Therefore, thenext step is to add road design constraints to elaborate a realisticsolution for the construction of low-noise pavements.


Twin wheels horn effect and pass-by noiseF-X. Becot, J-M. ClairetINRETS - LTE (Transport and Environment Laboratory)With a view for traffic noise reduction, a large research effort con-cerns the appraisal of traffic noise levels. While procedures formeasuring noise levels from light vehicles have been developedfor several years, the assessment of noise levels for trucks hasbeen intitiated rather recently. Because of the decrease of thepowertrain contribution, tyre noise becomes the limiting factor ofa noise reduction at driving speeds above 70 km/h for trucks.An important parameter for the tyre radiation, as for light vehi-cles, is the so-called horn effet, which modifies the distribution ofsound in both the space and frequency spectrum. Besides dif-ferent dimensions and characteristics, truck tyres differ from ve-hicles tyres in that they can be mounted as twin wheels. This is


expected to have a significant influence on the radiation of noise,but it is has not been clearly qualified. In this respect, this pa-per presents measurements of horn amplifications measured ina horizontal plane around twin wheels. The contribution of eachtyre of the twin wheel system is identified and compared to thecase of a single wheel system. Finally, an attempt for simulat-ing the resulting contribution to the pass-by noise including theDoppler effect is proposed and the consequences concerning theemission of truck tyres are discussed.


Study of Crossbar Tyres in Rolling ConditionsFrédéric Wullens, Wolfgang KroppDepartment of Applied AcousticsA correct description of the contact between a tyre and a roadis a crucial step towards the understanding and the predictionof tyre/road noise using deterministic models. The present workis about the study of crossbar tyres of the passenger car typein rolling conditions. Measurements were made on a crossbartyre loaded on a rotating drum and acceleration signals wererecorded on the tyre structure for both the tangential and nor-mal directions. The measurement situation was also modelledusing a deterministic three-dimensional contact model. Compar-isons between measurements and calculations show satisfactoryresults when it comes to pitching frequencies and global shapesof the acceleration signals. Another result is that it can be seenthat moment excitation of the tyre structure by each block hittingthe road at the leading edge is an important generation mecha-nism to include in models.


Acoustic Behaviour of an Automotive RadiatorChristoph Roentgen, Jens Prager, Bjoern PeterssonInstitut für Technische Akustik , Technische Universität BerlinOne of the major contributions to the pass-by noise emitted bycars is that propagated through the radiator. Essential, therefore,are the characteristics of the radiator, seen as an acoustic ele-ment. To describe the acoustic behaviour of the radiator, the the-oretical model for a porous absorber, proposed by Lord Rayleighis used. In this contribution, the results from such a model will becompared with those of experiments.



Influence of Geometry on the Acoustics of Lateral Open Cav-itiesJianrun Zhang, Jens Prager, Bjoern PeterssonInstitut für Technische Akustik , Technische Universität BerlinMost of the sound fields in realistic build-up systems can be seenas sound fields in partially open enclosures. Due to these par-tially open sides of the cavity and the resulting complex wallimpedances, the analytic description of the sound field becomesdifficult in particular the determination of the eigenvalues. How-ever, the influence of an irregular cavity shape on the sound fieldbecomes weaker duo to the high apparent absorption. In thiscontribution, a simple and alternative method is proposed to de-scribe the sound field in a laterally open, rectangular cavity adopt-ing a cylindrical model to avoid the complex eigenvalue problem.The approach is applied to simulate the sound field in an under-neath car cavity. The theoretical results will be compared withthose of experiments.


About the connection between measurements in the alpha-cabin and the theoretically reachable differences in level ofabsorbing materialsKlaus Pfaffelhuber, Christine Patsouras, Dimitrios Patsouras,Alexander BoschAKsys GmbHThe equivalent absorbing area of several absorbing materi-als (foams, various membrane absorbers, microperforated ab-sorbers) was measured in an alpha-cabin. Additionally, the leveldifferences which can be obtained by those materials were mea-sures in an anechoic chamber. For this a spherical sound sourceemitting white noise was covered by a square barrier whereasthe ground was spread with the respective absorber. The result-ing sound pressure levels were measured in varying distance tothe sound source and by means of varying aperture degree ofthe barrier. The in this way obtained level differences of the vari-ous absorbing materials were compared to the absorption coeffi-cients measured in the alpha-cabin. An excellent agreement ap-peared between the effective range measured in the alpha-cabinand the level difference obtained by the respective absorbing ma-terial.



Measurement and simulation of the acoustical impedance ofan internal combustion engine exhaustRene Boonen, Paul SasDepartment of Mechanical Engineering, K.U.LeuvenIn this investigation, the acoustical impedance of an internal com-bustion engine is measured and simulated. The measurementsare based on the two microphone transfer function method, whichis described in the standard ISO/FDIS 10543-2. The methoduses the transfer function between two microphones positionedon a waveguide connected to the impedance to be measured.Some improvements are proposed to this procedure, concern-ing the calibration of the measurement setup. New correc-tions are proposed to eliminate the speed of sound, the micro-phone locations and the the deviation between the microphoneresponses. The method is applied to measure the acousticalimpedance of an engine. The reflection coefficient at the engineexhaust is measured. From the reflection coefficient, the acous-tical impedance is determined. To prevent the engine to disturbthe reflection coefficient during the measurements, the engine isrun with an electric motor and the intake is sealed. The simula-tions are carried out using electrical analog circuits. The circuitsare built by analyzing the engine parts contributing to the acous-tical impedance. The electrical analog components are deter-mined using the geometrical data of the engine and the exhaustmanifold. The simulation results correlate well with the measuredimpedances . Also, some special cases are simulated, to de-termine the engine components which contribute primarily to theacoustical impedance.


Valves in exhaust-systemsHelmut VenghausArvinMeritor A6ET-Group Zeuna Stärker GmbH AugsburgFor controlling the acoustics or for sounddesign in exhaust-systems today valves are increasingly used. The modes of oper-ation of valves are very specific. On one hand they can be op-erated by an external steering-system to react on special engineconditions. The other valves are driven by the engine massflow.They can be activated by backpressure or the impact of the ex-haust gas. This presentation will give an overview on differenttypes of valves and their modes of operation. The influence onsound and on backpressure will be discussed.



Low Noise Urban Truck ProjectLudovic Greverie, Bernard FavreManufacture Française des Pneumatiques MichelinAs regards environment, the reduction of noise in urban areas isone of the major concerns of the European Union, and in partic-ular of France.Michelin, in partnership with Renault Trucks, INSA and Mar-monier propose within the framework of a PREDIT project to workon noise reduction of urban trucks.The objective is to obtain, under urban use conditions, noisecharacteristics improved from at least 50% compared to exist-ing situation. The originality of this project is on the one handthe wish to treat all the sources (driving, idle, tailgate, tailboard,shocks of handling, refrigerating unit...) and on the other handto be interested not only in the regulation levels but also in thequality of perceived sound by the residents. This project shouldend up in 3 years.Within the framework of this conference, a presentation of thefirst results, specially regarding the tire, will be made.

Tu. 8:30 Schuman Room acoustics : simulation, . . . II

Evaluation of room acoustical simulation softwareIngolf BorkPhysikalisch Technische Bundesanstalt, FB 1.6 SchallFor comparing room acoustical simulation programs several as-pects have to be considered: on the one hand the accuracy ofcalculations of room acoustical parameters can be checked withprescribed input data as done in the three round robin tests whichhave been carried out until now. On the other hand, quality crite-ria for such programs are also: the features for displaying results,auralisations (online/offline) and the usability. The methods usedduring the round robins will be discussed. The influence of theapplied calculation algorithms on the results cannot be derivedfrom this comparison; deviations from measured values can bereferred to inaccuracies in measurements or to the limits of geo-metrical acoustics at low frequencies. It also revealed that onlyskilled software users are able to get correct results even for sim-ple models.



Numerical Sound Field Modelling in Room Acoustics andWorkshops using Sound ParticlesJudicaël PicautLCPCMost of sound field modelling in room acoustics are based onclassical methods like ray tracing or the image-sources theory.Considering the large number of practical applications, theseclassical methods have been also extended or modified in or-der to take into account, as well as possible, the room shape(cubic rooms, corridors, low roomsoe), wall absorption and diffu-sion, atmospheric attenuation, the effect of fitting in workshop-soe following several and various approaches. However, onecan remark that lot of mathematical, empirical and numericalmodels have been proposed including such-and-such phenom-ena or room property, but practically none including all effectsfor all shapes. In this paper, we propose to use the concept ofsound particles for the numerical sound field modelling whateverthe room configuration. Using probabilistic approaches, we showthat such method allow to predict the sound field in rooms, includ-ing wall absorption and diffusion, atmospheric attenuation, scat-tering objectsoe with a good accuracy. An algorithm is detailed,and the statistical approach is described. Many numerical results(sound level and reverberation time) for cubic spaces, rectangu-lar rooms and workshops, corridors are given and compared withexperimental data.


About the influence of the reflection coefficient on simula-tion in room acousticsRoman Stumpner, Sebastian GoossensInstitut für RundfunktechnikIn order to assess the acoustical characteristics of studios(broadcast production rooms) being planned it is very useful tomake them audible by simulation. Therefore you need a high-quality-auralization of the sound field at a time when the roomsare still being planned and actually do not exist yet. Besides thegeometrical room dimensions the properties of sound absorbersdetermine the room acoustics. Especially in studios an extensiveuse of sound absorbers is typical. The efficiency of a sound ab-sorber depends on both, the external sound field on its surfaceand the internal sound field characterized by its impedance. Inorder to describe the non-diffuse sound field of a studio (accord-ing to our aim of the room acoustical simulation) the reflection


coefficient itself should not contain information about the exter-nal sound field. Hence the use of the reflection coefficient basedon diffuse field measurements is unsatisfactory. A better way is touse the complex reflection coefficient which depends on the an-gle of the sound incidence. Extensive absorber catalogues basedon complex measurements are not required. Instead of that thetheory of sound absorbers is used to solve the problem. With thismethod a lot of absorber types and all variations of these can becalculated with sufficient accuracy. The influence of the reflectioncoefficient on simulation in room acoustics is shown at theoreticalcalculations and measurements in practice.


Comparison of investigations using a mathematical and aphysical model with results of measurements in the originalroomThomas Behr, Hans-Peter TennhardtIEMB e. V. an der TU BerlinIt will be presented the results of investigations of soundfieldproperties of a room in the design state, obtained using amathematical model (computer simulation) and a physical model(scaled model). These results will be compared with the resultsof measurements in the ready-made original room. The occuringdifferences are evaluated by means of the limens of just percep-tible differences.


Analytical Derivation of the Reduction of Computation Timeby the Voxel Crossing TechniqueUwe StephensonUniversity for Applied Sciences HamburgPractical application of room acoustical simulation techniques stillsuffers from high computation times. Different algorithms to re-duce the time consuming search for ray-wall-intersections havebeen tested, mainly, as known from computer graphics, basingon spatial subdivision. For room acoustics, where the number ofsurface polygons (walls) is not so high, the voxel technique ap-pears suitable, however its performance was not yet investigatedup to now. Voxels are small cubes by which the space is subdi-vided. Only if a voxel intersects a wall (which is once checkedand stored before simulation) the intersection point needs to becomputed. The advantage: most voxels are empty. In this paper,by estimating the propabilities of such intersections, an analyticalformula is derived, by which the optimum factor of spatial sub-division and the factor of acceleration of the algorithm can beforecasted. It turns out, that the computation time increases only


with the square-root of K0 instead with K0 (the number of poly-gons of the room). Thus, on modern PCs, computation time fora full room acoustical simulation (impulse responses up to about10th order of reflection, level accuracy in the order of 0.3dB) evenfor highly complicated rooms (1000 polygons) may be reduced bya factor of 100, i.e. to a few seconds.


Equalization and fidelity of a sound environment simulatorBenoit Gauduin, Patrick BoussardGenesisThe aim of a sound environment simulator is to reproduce, in astudio, all the acoustical elements of a ”real environment”. Thefidelity of such system may be seen through the ability of repro-ducing: · the spatialisation / localisation of sounds · the loudnessof sounds · the spectral content of sounds Nowadays, there is noperfect way to record and reproduce all these elements: micro-phones and loudspeakers may degrade some of them. Hence,special treatments must be applied to the recorded signal in or-der to achieve the best compromise at the reproduction. We willdiscuss about the way to deal with the three points of fidelity listedpreviously. · The reproduction of spatialisation and localisation ofsounds is linked to the method used by the simulator: Binaural,Transaural, Stereo Dipole, Ambisonicsoe · The loudness repro-duction of sounds can be corrected by a gain factor in the simu-lator · The reproduction of the spectral content of sounds can becorrected by filters which will decrease the coloration introducedby the microphones and the loudspeakers. In order to obtain thegain factor and filters that have to be applied, two methods are atdisposal: · The coupled equalization consider the microphonesand loudspeakers as a whole system. · The decoupled equal-ization consider the microphones and loudspeakers as separatesystems. Measurement sessions have to be conducted. Theycan significantly improve the fidelity of the sound environmentsimulator.


Designtool AuralisationChristoph MoldrzykTU Berlin, FSP-PV/PRZA dummy head measurement based auralisation method and aworkflow for acoustical design of rooms with simulation softwarewill be presented. The use of binaural impulse responses basedon the measurement of a dummy head with rotating head towardsthe torso together with low latency head-tracking allows realis-tic auralisation. Simulation software based auralisation, dummy


head measurement based auralisation and acoustical situation inreality are compared. The results and implications like necessityof visual aid will be discussed.


Difference limen for early lateral energy fraction and late lat-eral levelIngo Witew, Gottfried BehlerInstitute of Technical AcousticsThe subjective perception of spatial impression in room acousticsis strongly related to early and late sound energy that reachesthe listener from lateral directions. Recent investigations indicatethat most parameters vary severely from one listening positionto another in the same sound field, even at very short distance.Although these variations have been shown in both, artificial andreal sound fields, the question if these variation are audible andif and how this is perceived by the listener is not fully clarified. Inthis study the difference limens for single number parameters re-lating to the two aspects of spatial impression, namely apparentsource width (ASW) and listener envelopment (LEV) have beeninvestigated. In this respect synthesized sound fields have of-ten been used for subjective tests. Typically, however, these aremuch less complex in regard to the density and spatial distribu-tion of the reflections. This may cause unwanted and unrealis-tic effects. In order to avoid the aseptic nature of such soundfields, measurements in four different concert halls and auditori-ums were taken. In a first step these measurements were con-ducted with suitable microphones to derive single number param-eters that describe the binaural impulse responses which wererecorded in a second step with a dummy head at the same po-sition. In subsequent listening tests volunteers were then askedwhether they can identify the member of an audio pair that in-heres the greater sensation of ASW and LEV. These statementsare used to derive the difference limen for the corresponding pa-rameters.

Tu. 15:30 Schuman Concert hall acoustics

CARMEN: a physical approach for Room Acoustic Enhance-ment SystemIsabelle Schmich, Jean-Paul VianCSTBIt is very common that the acoustic of ancient performing halls ormusical spaces cannot be improved by refurbishment works, be-cause of the high cost or because of the registered building. Evenfor high standing performing halls, demand of multipurpose halls,


which require variable acoustic, is also growing. A new Acous-tic Enhancement System has been developed and experiencedin several halls. The physical statements on which CARMEN isbased are presented, as well as objective and subjective assess-ment of the enhanced acoustics.


Roomacoustical Conditions for the Landau Festival Hall,GermanyErnst-Joachim Völker, Wolfgang TeuberInstitut für Akustik und BauphysikThe 850 seats concert hall has been totally rebuild during thelast years and was reopened on February 12, 2003 with a con-cert of the Rheinland Pfalz Philharmonic Orchestra. The greatevening was an another milestone in the long history of the hall,now again in the glamour of the former Fugendstil when the hallwas build in 1908. In the fifties, more direct sound was pref-ered with a reverberation time of around 1,5 seconds and 800seats, unoccupied. Furtwängler conducted the Berlin Philhar-monic Orchestra in 1956 and was enthusiastic about the greatacoustics. For the authors, the acoustical design was a judgechallenge. The hall should again sound bigger with mutch morereverberation. But, what about theater, musicals, jazz and pop-music, rock-bands and congresses? The achievements will bepresented including model studies and first experiences.


Room Shape and Sound ShapeHans-Peter TennhardtIEMB e. V. an der TU BerlinIt will be given a view of the potential inter-relation of room andsound shape. The ground plan with the classical rectangular andthe polygonal shape is the central feature of the room that willbe considered. Differences and similarities of sound colouration,reverberation time and reverberation energy will be explained bytypical examples.



Acoustic Design of the National Grand Theatre of ChinaJean-Paul VianCSTBWhen designing a new opera or concert hall, the architectural re-quirements for excellence are most of the times conflicting withthe similar acoustic requirements for excellence. Good compro-mises have to be sought; with the well known difficulty that seeingmostly predominates over hearing. The National Grand Theatreof China, Beijing, under construction is composed of three largeperforming halls: the Opera (2400 seats), the Concert Hall (2000seats), the Theatre (1500 seats). During the design of the Opera,the architect became unhappy with the layout proposed for theinternational competition providing optimal first lateral reflectionsto the public. Series of curved walls were desired by the archi-tect from architectural points of view that create a lot of acousticshortcomings. Decision has been made to dissociate the visi-ble walls made acoustically transparent from the acoustic ones.The acoustic design of the opera, including computer modellingis presented.


Heineken Music Hall - Design of and validation measure-ments in a great pop music hallKlaus Lorenz, Rob Metkemeijer, Yves DekeyrelPeutz GmbH”Heineken Music Hall - Design of and validation measurementsin a great pop music hall” Abstract This lecture deals with an ex-traordinary hall: the Heineken Music Hall in Amsterdam. This hallwas designed for the main purpose of high-quality pop concertsfor an audience of up to 5500 persons and its acoustic proper-ties have become widely admired since its opening. Becausemost of the events planned in the hall make use of PA systems, alow reverberation level and low reverberation time in all frequen-cies, even the lowest, was required as well as sufficient diffusion.The design used a certain philosophy: to create an acoustic en-vironment close to free field conditions. This requires extrememeasures to control the absorption, diffusion and reverberationproperties especially at low frequencies. Thus special absorp-tion and diffusion elements for the walls and the ceiling had to bedesigned. Measurements of the designed absorber constructionwere performed during the construction of the hall. After its com-pletion impulse response and reverberation measurements weretaken in the hall to evaluate the acoustic properties. It proves thatthe design requirements were met, such as an almost free-fielddecay (-5.5dB/ 2r) ; a remarkably short reverberation time of 1.3


seconds was measured in the empty hall with a volume of 48000m3.


Room acoustics for 4 uses - Großes Haus StaatstheaterMainzXueqin Zha, Helmut Fuchs, Horst Drotleff, Xiaoru ZhouFraunhofer Institut BauphysikSince different uses of auditoria, such as concert, opera, the-atre and ballet, need a distinctive room acoustic environment,high-quality auditoria normally serve only one or, at most, twouses, e.g. concert and opera. On the other hand, the manage-ment of a cultural site usually desires a multi-purpose thea-tre, inorder to react flexibly to customers demands. Acousticians aresome-times tempted to design fairly cost-intensive and some-times almost impractica-ble ”variable acoustics”. The ”GroßesHaus” of the Staatstheater in Mainz has been redeveloped fromground. This opportunity was taken and the ”house” was givena new room acoustic design which serves four uses in one. Thiswas based on smoothing the room response over the whole fre-quency range in the auditorium and the coupled stage. By anenlargement of the volume of the auditorium and the invisible in-stallation of novel sound absorbers, which effec-tively work at lowfrequencies only, this goal has been achieved. The useful acous-tic energy from the stage and the orchestra pit is directed onto theaudi-ence by means of reflectors. Detrimental reflections are fo-cussed away from the spectators. The feedback from spectators,musicians and conductor regard-ing the acoustics for all uses ispositive.


Acoustic improvements of the working conditions for musi-cians in orchestra pitsHorst Drotleff, Xueqin Zha, Helmut Fuchs, Michael LeistnerFraunhofer Institut BauphysikMusicians in orchestra pits suffer from extremely high soundpressure levels and have to perform their jobs under severe dif-ficulties concerning the hearing of the sound of their own instru-ment as well as that of all other members of an ensemble. Fac-tory workers, who are exposed to weighted noise levels exceed-ing 90 dB(A), are regularly forced to wear ear plugs in orderto protect them-selves. In orchestra pits the ”noise level” of-ten reaches 110 dB(A) and more. Highly qualified and artisti-cally motivated musicians however, refuse to wear ear plugs ofany kind since these deteriorate the necessary communicationamong them. Instead, the installation of novel compact low- and


mid-frequency absorber modules on the walls and overhang ofthe pits will be shown to tackle the problem of poor music intelli-gibility at its roots. This concept of improving the acoustic workingconditions has been realised successfully in eight orches-tra pitsto the full satisfaction of the musicians and equally important theircon-ductors without affecting the transmission of the sound fromthe pit into the auditorium.

Tu. 18:10 Schuman Environmental & machinery noise I

Underwater noise emissions from offshore wind turbinesKlaus Betke, Manfred Schultz, Rainer MatuschekInstitut für technische und angewandte Physik GmbHIn areas with an extensive use of wind energy, it has become dif-ficult to find appropriate sites for new wind turbines. This is oneof the reasons for establishing an offshore wind energy industry.Moreover, it is assumed that the stronger and steadier flows ofelectricity from sea winds will make up for the extra expense ofbuilding turbines offshore. Numerous wind farms are planned orproposed to be raised in the German parts of the North Sea andthe Baltic, with a total of more than 5000 turbines of 2.5 to 5 MWeach. During construction, pile driving operations can producemaximum underwater sound pressures of several kPa at 1 km,which might be harmful to the sea fauna, in particular to mam-mals like harbour porpoises or seals. Wind turbines in operationmay also emit gearbox and generator noise into the water. Inthis paper, we will present various hydroacoustic measurementsmade at various distances from offshore pile drivers. Further-more, underwater noise radiated from a 2 MW class turbine hasbeen measured over a 4-week period. Results, sound radiationmechanisms and ecological implications will be discussed.


Schallimmission auf der Deutschen Antarktisexpedition2002Peter Fürst, Volker Warneckecdf Schallschutz DresdenWährend der XXII. überwinterungskampagne auf der deutschenAntarktisstation ,Alfred Neumayer” des Alfred-Wegener-Institutfür Polar- und Meeresforschung wurde während der überfahrtmit dem Forschungsschiff ,Polarstern” und während der über-winterung in der unter dem Eis befindlichen Forschungssta-tion Schalldruckpegel gemessen. Die Messungen erfolgtenin den Mannschaftsräumen und Schlafräumen der Forscher.Sowohl auf dem Schiff (Antriebsdiesel) als auch in der Sta-tion (Energieversorgung mit ständig laufendem Dieselmotor) sind


neben Klimageräuschen insbesondere die Körperschalleintra-gung der Motoren immissionsprägend. Daneben sind in den La-boren Schalldruckpegel durch Messgeräte und Computer auffäl-lig. Innerhalb oberirdischer Stationen treten teilweise sehr erhe-bliche Windgeräusche auf. Die Schallimmissionen sind je nachBeobachtungsstandort sehr unterschiedlich. Es treten deutlichetieffrequente Anteile hervor. Außenmessungen sind wegen derTemperaturen im zweistelligen Minusbereich nicht möglich. DieMessergebnisse innen der Schalldruckpegel und Frequenzanal-ysen werden vorgestellt.


Das deutsche Berechnungsverfahren für Lärmbelastungdurch den StraßenverkehrWolfram BartolomaeusBundesanstalt für StraßenwesenAm 16. August 2003 veröffentlichte die EU-Kommission eineEmpfehlung über den ,Leitfaden für die geänderten vorläufigenBerechnungsmethoden für Industrie-, Flug-, Straßenverkehrs-und Eisenbahnlärm und diesbezügliche Emissionsdaten”. Darinwerden die notwendigen Anpassungen der französischenBerechnungsmethode ,NMPB-Routes-96 (SETRA-CERTU-LCPC-CSTB)” an die EU-Richtlinie 2000/49/EG dargestellt. DieAufgabe bestand nun darin, aus dem deutschen Lärmprogno-severfahren, den ,Richtlinien für den Lärmschutz an Straßen”(RLS-90), eine geeignetes Interimsver-fahren für die Ziele derEU-Richtlinie (Lärmkartierung und Aktionspläne) zu entwi-ckeln.In diesem Beitrag werden die änderungen der angepasstenRLS gegenüber der ur-sprünglichen Version dargestellt. Anhandvon ausgewählten Rechenbeispielen wer-den die Auswirkungendieser änderungen auf die Ermittlung der Immissionsschall-pegel auch im Vergleich zur angepassten Interimsmethode derEU-Kommission auf-gezeigt.

Tu. 8:30 Tivoli 1 Temporal aspects in the perception . . .

Ear-catching features of time-variant speechUte JekoschInstitut für Kommunikationsakustik (Web: www.rub.de/ika)In modern speech communication systems such as mobilephones or VoIP, time-variant distortions can be perceived quiteoften. For system design it is essentially important to know whichdistortions are acceptable and which ones will not be tolerated bythe user in the end. As a matter of fact, two different perspectivescan be taken to capture listener reactions: one focuses on invari-ance and the other on variation. What invariance is concerned,the question is why individual perceptual behaviour with regard


to objects of perception and resulting quality judgements is com-parable even accross a huge number of subjects; with regardto variability research goes into the question of why subjects donot react and judge differently although signal characteristics ofperceived speech vary significantly. As a matter of fact, speechperception is a process of selection, organization, coordinationand structuring. These processes are ruled to a certain degree.Human beings have so-called ’schemas’ at their disposal percep-tual processes are based on. When investigating schemas moreanalytically, one very soon comes across the theory of ’Gestalt’perception. In this paper ear-catching features of speech soundswill be discussed. The perspective taken is the one of rulingschemas in the context of the following questions: How does thehuman listener manage to select certain characteristic features ofthe auditory event and take them as information carrying units?What are invariant types of behaviour as opposed to individualor spontaneous ones? What is the role of the context? Whatare basic signal characteristics which stimulate a specific type ofbehaviour?


Comparaison between four methods of loudness estimationfor stationary and non-stationary soundsIsabelle BoulletLMA CNRSThis research is part of a study designed to propose a new modelof loudness estimation for impulsive sounds. The purpose of thisresearch was to compare different methods to measure the loud-ness of various kind of sounds. The aims were to determine: 1)the inter-individual variability of each of the four methods of loud-ness estimation, 2) whether this variability depends on the tem-poral features of the stimuli (stationary sounds, impulsive sounds,repeated impulsives sounds). The four psychoacoustical tests ofloudness estimation (either in sones or in phons) studied in thepresent research were the magnitude estimation without refer-ence, the method of adjustment, an adaptive method (2 down-1up and 1 down-2 up) and a multiple-tracking adaptive method. Iwill first describe the different stimuli used in the study and thenthe four psychoacoustical tests. I will present the advantages anddrawbacks of each method. The study showed that the methodof adjustment gives a good precision/duration ratio. Moreover, weexamined the loudness function at 1 kHz from which the relation-ship between sones and phons is deduced. Then, I will describethe limitations of the mathematical relationship between sonesand phons. I wil conclude that it is necessary to be very careful


when comparing values of loudness obtained in sones with thoseobtained in phons.


Loudness of impulsive sounds: measurements versus mod-elsIsabelle Boullet, Sabine Meunier, Alexander Raake, SebastianMöller, Ute Jekosch, Georges CanevetLMA CNRSLoudness measurements are essential for evaluating environ-mental impact and annoyance of noises. But environmentalnoises are mostly non-stationnary, or even impulsive, and thereis no standard procedure to measure their loudness; models tocalculate it are also missing, in contrast with the case of station-nary sounds. The purpose of this study was to undertake a newseries of experiments to measure loudness of impulsive sounds,and hopefully to build algorithms that would yield a reliable esti-mate of this loudness. Previously, we have shown that the loud-ness of both environmental and synthetic impulsive sounds canbe expressed as a product of two power functions, of energy andof decay time, each with its own exponent. This finding that loud-ness is a power function of decay time is new, and further testswere run to exactly determine the exponent of this function. Itwas found that the exponent also depends on signal energy andspectrum, in a way that will be described in the presentation. Fi-nally, an experiment was run, in which loudness of different kindsof impulsive sounds (pure tones, environmental sounds, trains ofimpulsive sounds) was evaluated by magnitude estimation, withGerman and French listeners. Loudness was also calculated us-ing different criteria: (i) N4, N5, N10 with Zwicker’s model and(ii) our new model for impulsive sounds, and compared to exper-imental results. We will discuss how loudness models can beimproved to apply to impulsive sounds as well.


Temporal asymmetry in loudnessPatrick Susini, Stephen McadamsIRCAMA study by Canévet and Scharf (1990) showed that sounds thatare continuously decreasing in level are perceived to decreasein loudness more than two sounds presented successively withthe same difference in level. The authors explained this differ-ence by an inherent auditory asymmetry which they called au-ditory ’decruitement’. Using the same kind of stimuli, Neuhoff(1998) showed that loudness change is judged greater for a con-tinuously increasing than for a continuously decreasing sound


with the same change in level. Neuhoff explained this differ-ence by an ’ecological’ point of view that human beings are moreaware of increasing signals. More recently, using short- durationstimuli (<250 ms), Stecker and Hafter (2000) compared soundswith opposite attack/decay characteristics; F-S (fast-slow) and S-F (slow-fast). The results showed that S-F stimuli were louderthan F-S stimuli having the same energy. The authors explainedtheir results by a mechanism of ’decay suppression’. The presentpaper presents the different arguments that explain the effectof temporal asymmetry on loudness. Then, a set of loudnessevaluations obtained using increasing and decreasing ramps ofidentical duration shows the same asymmetric phenomenon. Weshow, however, that it can be explained by a short memory effectcalled the ’recency effect’.


Continuous evaluation of noise comfort in a busEtienne Parizet, Nacer Hamzaoui, Lionel Segaud, Jean-RenéKochLab. Vibrations Acoustique, INSA Lyon - Bât. 303The goal of this study was to use the ’continuous analog cat-egory scale’ method for the evaluation of comfort in a bus. Along recording (162 s) was realised in a bus driving in a typicalway (including acceleration and coast-down, opening and clos-ing of doors, etc.). A modified version of that recording was cre-ated by digitally modifying some particular events. About fiftylisteners continuously evaluated the auditory comfort of thesetwo sequences, by moving a cursor sliding along a categoricalscale; they also evaluated the overall comfort of each sequence.When considering the overall comfort evaluation, the panel couldbe divided in three groups (listeners who preferred the modifiedsound, those who preferred the original one and those who evalu-ated the two stimuli as equally comfortable). The continuous eval-uations averaged over these three groups were different, whichcan be an indication that listeners really evaluated comfort andnot loudness. Nevertheless, instantaneous evaluation was lessaccurate than the overall one, which indicates that more work isneeded to improve the method.


Perceptive qualification of the engine sound characterVincent Roussarie, Florent RichardPSA Peugeot CitroënFor over 2 years PSA has been studying the sound identity of 4cylinders vehicles. Using free sorting experiences we observedthat the sound of vehicles in dynamic situations such as full load


acceleration can be sorted at least in 4 categories. One categoryfor which sound identity is pregnant in consumer’s choice is theso called ’sporty class’. Thus we focused on the link betweensignal and perceptive attributes of this category through specificexperiments using synthetic sounds. The aim is to qualify sportyidentity using objective signal criteria. HARTIS, the sound designsoftware we developed using IRCAM’s jMax programming envi-ronment, allowed us to prepare re-synthesis car sounds for threemain experiments :- Influence of high engine orders on the perception of roughness,- Influence of booming noise on the gene caused by enginesound,- Influence of booming noise and roughness on the perception ofsporty identity.The results of those experiments highlight that roughness andbooming noise can influence perception of sporty identity in dif-ferent ways. Indeed we emphasized subject classes with differentrepresentation of a sporty car sound. In addition, we now havesignal keys to explain the perception of different roughnesses andthe annoyance caused by booming noise. Those experimentshighlighted the fact that different sporty identities exist, and em-phasized important signal criteria for each sporty class observed.


The Bouncing of Balls: Influence of Temporal and SpectralChanges on PerceptionChristophe Stoelinga, Hubertus Peeters, Ines LopezEindhoven university of technologyThis contribution is concerned with physical modeling for the de-sign of perception tests of non-speech sounds. The restitutioncoefficient of a ball bouncing on a plate can be calculated fromHertz’ contact theory, Newton’s second law and the response ofthe plate. We adapted this method by calculating the plate re-sponse from the point impedance of the plate. We calculatedthe restitution coefficient both in the middle of the plate and atthe edges, where the restitution coefficient is three times lower.Measurements showed good resemblance between predictedand measured restitution coefficients in the middle and near theedges. Using the same theory we calculated the spectral con-tent of the sound produced by each individual bounce. We be-lieve that the restitution coefficient and the spectral content arethe two most important cues for the listener to detect the size ofthe bouncing ball. Therefore, we recorded the sounds of threebouncing balls of different sizes. Since the restitution coefficientis directly related to the temporal distances between successive


bouncing events, we realized seven different values of the restitu-tion coefficient by changing the length of the silent gaps betweenthe individual bounces. In a perception experiment we asked lis-teners to determine the most natural sound, and we asked for thelargest ball. Two groups of test persons could be distinguised:when asked for the most natural sound the first group chose thesounds with the lowest restitution coefficient while the other grouprecognized the original unaltered sounds.


The influence of non-stationary vibrations on the quality ofnon-stationary product soundsM. Ercan Altinsoy, Ute JekoschInstitut für Kommunikationsakustik (Web: www.rub.de/ika)Mechanical vibrations of different products generate usuallynoise and additionally tactile information. In most cases, theseauditory and tactile information are non-stationary signals. In thepresent study, a psychophysical experiment was conducted toinvestigate the influence of non-stationary vibrations on the qual-ity of non-stationary product sounds. In this experiment, non-stationary drill noise and vibrations were presented to the sub-jects via headphones and through a force-feedback mouse si-multaneously. The influence of non-stationary vibrations on thequality of non-stationary product sounds will be discussed on thebasis of the results of the psychophysical experiment.


How do users perceive speech quality under combined ”sta-tionary” and non-stationary degradations?Alexander RaakeInstitut für Kommunikationsakustik (Web: www.rub.de/ika)With the advent of packet-based transmission, telephone usersare increasingly confronted with new types of speech quality im-pairments. The main feature of these impairments is that they aretime-varying. In this paper, the question is addressed, how sub-jects rate the speech quality of a telephone line which is impairedby both ”stationary” degradations known from traditional tele-phone networks and highly ”non-stationary” degradations, e.g.due to time-varying packet loss. To this aim, a series of threeconversation tests was conducted. In each of the tests, burstpacket loss was presented in combination with one ”stationary”degradation type known from traditional wireline networks (noiseof different levels; different transmission delays; talker echo ofdifferent echo attenuations). The study is complementary to thatpresented at the DAGA03. Instead of random packet loss, burstpacket loss was used as the non-stationary degradation type. In


principle, it is known from past tests, how subjects integrate overthe instantaneous quality of a link under time-varying packet lossand establish a percept of overall quality. It is also known, howsubjects judge the speech quality of a link in case that one ofthe PSTN-typical ”stationary” degradations is present on the line.This paper investigates, whether the subjects’ overall quality rat-ings for combined impairments reflect an instantaneous weight-ing of ”stationary” and non-stationary degradations, followed byan integration over the resulting instantaneous quality, or whetherthe different types of impairments are evaluated instantaneouslybut independently, and the percept of overall quality results froma weighting of overall features.


Temporal Aspects in the Prediction of Perceived Audio Qual-ity DifferencesRainer Huber, Birger KollmeierMedizinische PhysikThis talk presents a new computational method for the predictionof perceived overall audio quality differences using an auditoryprocessing model. The method represents an expansion of thespeech quality measure qc of Hansen and Kollmeier (2000). Itemploys a quantitative model of the ,effective” signal processingin the auditory system by Dau et al. (1997). This model partic-ularly accounts for the processing of non-stationary sounds andwas validated by a number of psychoacoustical masking exper-iments. In the framework of the quality assessment method, itis employed to provide internal representations of a given pairof reference and test signal whose quality difference is to beassessed. The cross correlation between these internal repre-sentations serves as a measure for the perceptual similarity andtherefore for the quality of the test signal relative to the referencesignal. In order to become capable of predicting perceived qualitydifferences for any kind of audio signals and distortions, the rela-tionship between the time varying instantaneous and the overallaudio quality had to be modeled as well. The optimum estimate ofthe perceived overall audio quality difference was found to be the5%-quantile of the ,loudness”-weighted sequence of short-time(10 ms) cross correlation coefficients. The method was testedusing a large database of subjectively rated audio signals. Thistalk will focus on the influence of model parameters concerningtemporal aspects of the quality assessment on the prediction per-formance.



An Approach for Instrumental Evaluation of Time-varyingSpeech Quality in an IP-testbedFlorian HammerTelecommunications Research Center Vienna (ftw.)Non-stationary cross-traffic in the underlying IP network causesimpairments of voice over IP (VoIP) transport which result in atime-varying degradation of the speech quality as perceived bythe user. Subjective testing of the perceived speech quality ishardly feasible due to the huge amount of speech data result-ing from various network conditions. Thus, we strongly favoran instrumental quality assessment approach based on an IPtestbed which provides the possibility of emulating realistic Inter-net cross-traffic. Moreover, the provision of various QoS mech-anisms in the testbed allows to shape the traffic and thus to im-prove speech quality. This paper introduces a quality measure-ment method that facilitates intrusive instrumental speech qualityassessment. The relation of realistic Internet cross-traffic, therespective packet statistics and the corresponding quality varia-tion are explored in detail. Furthermore, we investigate also theinfluence of the speech sample length on the results of the instru-mental speech quality estimates.

Tu. 16:50 Tivoli 1 Outdoor sound localization

Source Detection and Localization using Widely SeparatedSpecial Arrays : Theoretical Study and Experimental ResultsSébastien Hengy, Pierre Naz, Patrick GounonI.S.L. : Institut franco-allemand de Recherche de Saint LouisIn order to improve the soldier’s protection and efficiency in hos-tile environments, the French German Institute of Saint Louis hasdeveloped an original array: a head equipment (HE) fitted withone or more microphones, a GPS receiver and a magnetometer.Each man wearing this HE can then be considered as a part of alarge global array. Using this kind of array involves several con-straints: - the global array has never the same shape due to themovements of the soldiers, - perturbations due to the inaccurateknowledge of the location of the constituting elements must bemet, - the ”acoustic shadow” generated by the HE has to be com-pensated. First, we studied the behaviour of a large array withsensors spread randomly on a 10,000 square meters surface. Inthis case, high resolution localization methods like MUSIC areapplied using a spherical wave approximation. This allows forthe estimation of the Direction Of Arrival (DOA), as well as forthe estimation of the exact position of the acoustic source. Then,using numerical simulations, we measured the consequences of


an inaccurate knowledge of the microphones location. Measure-ments in an anechoic room confirmed the results obtained by thesimulations. Finally, open field measurements using a large arraymade up of 2 HE arrays and one classical triangular antenna tookplace in October 2003. Synthesized vehicule noises (generatedby speakers) and actual rifle shots were recorded. The resultsof the estimation of the localization of the sources are here pre-sented.


Basic Investigations of Microphone ArraysChristian Schulze, Andreas Zeibig, Dietmar RichterInstitut für Akustik und SprachkommunikationIn order to localize and separate sound sources at structures inair flows a microphone array was developed. In advance basicinvestigations about the generation of directional characteristicsof microphone arrays were carried out. The knowledge obtainedduring these investigations illustrated on the example of a linearray will be the content of this presentation. A specifically devel-oped computer simulation allowed the calculation of the transferfunctions of different microphone distributions as well as exam-inations of the influences of array geometry, signal parametersand evaluation algorithms on the directional characteristic of themicrophone array. On the basis of the simulation results an ap-propriate microphone array for the detection of the aeroacousticsources mentioned before was found. The application of a fre-quency band filter algorithm corresponding to the transition fromsingle-frequent to band limited sound source detection providedconsiderable improvements in the directional characteristic. Theobtained simulation results are to be discussed and comparedwith practical measurements.


PILAR Acoustic Gunshot Detection & Localization system :Principles of acoustic localization of small caliber gunshotsFrançois Magand, Alain Donzier, Frédéric Molliex01dB Acoustics & VibrationAcoustic devices have been used on the battlefield since theWorld War 1 for the localization of Artillery. Localization principlewas based on the measurement of time of arrival of the soundgenerated by the muzzle blast at different locations. The tech-nique may be extended to the localization of supersonic shots ofsmall arms’ fire. Localization is based on the measurement oftwo distinct transient sounds : the shock wave generated by thesupersonic bullet and the muzzle blast generated by the rapid dis-charge of propellant of the weapon. Depending on the deployed


configuration (one or two acoustic arrays) and on the miss dis-tance, localization gives the direction (azimuth & elevation) andrange of the origin of fire, the bullet trajectory as well as informa-tion on the bullet speed and identification (caliber class). In thispaper, the basic principles of the PILAR localization principlesare exposed and discussed. A special consideration is paid tothe analysis of difficult localization cases, such as application inurban areas for which background noise, reverberation and mul-tiple echoes are of concerns, or burst shots where a correct iden-tification of wave type is often more difficult. Some experimentalresults are also presented and commented. PILAR system is anacoustic devices dedicated to the detection and localization ofsmall caliber gunshots. It is composed of one (or two) acousticarrays, a compact Digital Signal Processing unit, and a laptopunit for the display of results. The system and the embedded al-gorithms are the results of more than 10 years of experience atMETRAVIB RDS.


Detection and Localization with Encapsulated MicrophonesPascal Hamery, Pierre NazI.S.L. : Institut franco-allemand de Recherche de Saint LouisDetection and localization of gun noises with microphones havebeen known for several decades and efficient devices are nowproduced. However, for the detection and localization of snipers itis difficult to conciliate the measurement of signals of high (Machwave of the projectile) and low (muzzle wave at a distance) levelin a given background noise environment. To work out this prob-lem we propose to put two microphones in a same macro-sensor.The characteristics of the first microphone are chosen to fit theparameters of the high level shock wave (Mach wave of the pro-jectile), those of the second microphone to fit the parameters ofthe low level wave (muzzle wave at a distance). These micro-phones are enclosed in cavities which are design to have fre-quency characteristics corresponding to the frequency domain ofthe two interesting signals. This macro-sensor allow, while hav-ing a low sampling rate, to assess the physical characteristicsof the two waves (peak pressure, wave duration). Furthermore,the microphones being encapsulated in a cavity with very littleopenings, they are protected from external agents. A prototypehas been made in order to validate the principle. Experimentalresults are compared to those obtained with a classical antenna.



Large eddy simulation of acoustical propagation in turbulentchannel flowMarie Haberkorn, Vincent Pagneux, Gilles Bouchet, Yves Aure-gan, Pierre ComteIMFS UMR7507 - ULP/CNRSVelocity fluctuations, caused either by imposing sound on a tur-bulent channel flow or by pulsating the flow, generate a shearwave at the wall. This shear propagates into the boundary layerand decays within the turbulent counterpart of the laminar Stokeslength. Ronneberger & Ahrens (1977) determined in these twoways the damping of sound by turbulence in experimental inves-tigation of the wall shear stress: at high driving frequencies thedamping is not influenced by turbulence, for low driving frequen-cies turbulence increases the sound attenuation and for a rangeof driving frequencies, the damping is surprisingly reduced byturbulence. This was recovered in Large Eddy Simulation of apulsating channel (Scotti & Piomelli, 2001), but at too a high aforcing amplitude to be relevant to acoustical propagation. Weperform analogous LES in which the pulsation is applied to apassive scalar, so that retroaction on the turbulent flow is sup-pressed. Different forcing frequencies and diffusivity of the scalarare considered. The trends mentioned above are recovered forhigh and low frequencies, but the reduced attenuation (with re-spect to that in laminar flow) at intermediate frequencies is nolonger observed. The time evolution of the spatial organizationof the scalar field is investigated. Références : RonnebergerD. and Ahrens C.D., 1977, Wall shear stress caused by smallamplitude perturbations of turbulent boundary-layer flow: an ex-perimental investigation, J. Fluid Mech., 83, 433–464. Scotti A.and Piomelli U., 2001, Numerical simulation of pulsating turbulentchannel flow, Phys. Fluids, 13(5), 1367–1384.

Tu. 8:30 Tivoli 2 Active control II

Mode Structure and Adaptive Control of the Jet-Edge-FlowArno Ickler, Dirk RonnebergerDrittes Physikalisches Institut GöttingenThe stabilisation of the plane laminar jet-edge-flow is studied withthe general objective to gain experience in flow control. The con-vective instability of the jet combined with the feedback of pres-sure oscillations from the edge to the nozzle results in a globalinstability leading to various modes (stages) of jet oscillations de-pending on the distance between nozzle and edge. A feedbackcontrol system shall be added such that the flow becomes sta-ble. The jet deflection measured by a realtime image processingsystem is fed back to an actuator imposing a pressure gradient


on the flow. One of the main differences between the jet-edge-system and most mechanical and electrical feedback systems isbesides the inherently high number of degrees of freedom thefact that an exact equivalent open loop system cannot be real-ized. The relevant system dynamics is identified by an adap-tive controller, which needs a small-amplitude broad-band testsignal, in order to synthesize a stabilising feedback filter. Forsmall distances between the nozzle and the edge the mode ofjet oscillation is not changed by the control action and a goodsupression of the oscillation is achieved. However by increasingthe nozzle-edge-distance, the system becomes more sensitiveto the parameters of the controller and finally escapes into an-other destabilized mode of oscillation. These destabilized modesresemble the higher natural modes of the uncontrolled jet-edge-system. Surprisingly these modes may persist for a long time.The relation between the mode structure and the controllability ofthe jet-edge-system will be presented.


Active Resonance Control at the Audi aero-acoustic windtunnel (AAWT)Fabian Evert, Hans MiehlingMüller-BBM GmbHA well-known problem associated with open-jet wind tunnels isthe occurrence of low frequency pressure and velocity fluctua-tions. This so-called ’wind tunnel buffeting’ negatively affects theflow parameters and thus the quality of both aerodynamic andaeroacoustic measurements. The observed disturbances mainlyoriginate from a periodic vortex shedding at the nozzle, whichsupports resonant modes of the tunnel duct. In principle, thedestruction of large-scale vortices by passive means leads to adisturbances attenuation. However, due to the additional higherfrequency noise generated by such devices, these methods areinapplicable to aero-acoustic wind tunnels. Therefore an activecontrol scheme for the suppression of wind tunnel buffeting hasbeen developed and tested at the Audi aero-acoustic wind tun-nel facility. This control system, termed Active Resonance Con-trol (ARC) utilizes a global control of the resonant duct modesin order to suppress the generation of disturbance. Both the un-derlying theory of disturbance generation and compensation, aswell as operational experiences with the ARC-system will be pre-sented.



Experimental Investigation of Active Control of the TonalNoise Components of Axial Turbomachinery with Flow Con-trolJan Schulz, Wolfgang Neise, Michael MöserTechnische Universität Berlin, Sonderforschungsbereich 557The aim of the project is to reduce the tonal noise componentsof axial turbomachines using active noise control. While conven-tional methods use loudspeakers, the secondary sound field isgenerated by flow control in this study. The flow conditions nearthe blade tips are disturbed by blowing air into the blade tip regionthrough nozzles (vortex generator jets), which are installed in thefan casing wall. Piezo elements are used as alternative actuatorsto disturb the flow. In this way, additional periodic forces are setup which result in aeroacoustic secondary sources. They can becontrolled such that a noise reduction of the tonal componentsis achieved. Furthermore the influence of the flow control on theaerodynamic behaviour of the test object is observed. Resultsusing steady blowing will be presented. The physical backgroundof the generation and superposition of the secondary sound fieldas well as the influence of different parameters will be discussed.The results will be interpreted with regard to the reduction of theblade passage frequency level, dominant azimuthal mode andoverall noise level. In the experiments the blade passage fre-quency level was reduced up to 20dB, where the overall noiselevel dropped by 12dB. In certain cases it was possible to reducethe dominant azimuthal mode of the order m=2 by 40dB. Inter-mediate results of the continuative experiments with unsteadyblowing, synchronised with the impeller at blade passage fre-quency, will also be presented. This study was supported bythe Deutsche Forschungsgemeinschaft (German Science Foun-dation).


Adaptive and Robust Control for the Reduction of TonalNoise Components of Axial Turbomachinery with Flow Con-trolMaiko Garwon, Jan Schulz, Bram Satriadarma, Rudibert King,Michael Möser, Wolfgang NeiseInstitut für Technische Akustik , Technische Universität BerlinThis paper presents results of a research project using robust andadaptive feedback control algorithms for the reduction of tonalnoise components of an axial fan by flow control. The active noisecontrol is achieved by specific distortions of the flow conditionsnear the impeller blade tips which results in an aeroacoustic sec-ondary field. This can be realised by blowing air into the blade tip


region through nozzles in the casing wall. An extremum-seekingcontroller is used to find the optimal mass flux, which determinesthe amplitude of the secondary sources. The phase was con-trolled by geometrical parameters. The experimental investiga-tions demonstrate the performance of the proposed controller forhigher order mode sound fields. To investigate the robustness ofthe closed-loop disturbances such as changing operating points,non-uniform inflow conditions and a 33% deviation of the revolu-tion of the fan were simulated. In all cases the controller reactedon the changed operating conditions and determined the optimalmass flux, achieving a blade passage frequency level reductionof 15dB for the tested configuration. The radiated sound of thetonal noise components in the far field is mainly determined bythe dominant azimuthal duct modes generated by the rotor-statorinteraction. Therefore a robust H∞-controller based on black-box modelling of the non-linear process dynamics was synthe-sised additionally, to suppress the dominant mode. Further ex-periments will focus on a controller including the adaptation ofboth, amplitude and phase of the aeroacoustic secondary field.This study was supported by the Deutsche Forschungsgemein-schaft (German Science Foundation).


Design of an active exhaust attenuating valve for internalcombustion enginesRene Boonen, Paul SasDepartment of Mechanical Engineering, K.U.LeuvenAn active silencer to attenuate internal combustion engine ex-haust noise is developed. The silencer consists of an electricallycontrolled valve connected to a buffer volume. The pulsating flowfrom the engine is buffered in the volume and the valve resistanceis continuously controlled such that only the mean flow passesto the atmosphere. This flow is free of fluctuations and conse-quently free of sound. The design of the active silencer is carriedout using electrical analog circuits. First, the interaction betweenthe active silencer and the engine will be studied using an analogcircuit including the combustion engine and a linearized activesilencer. Then, a detailed valve model is built in a separate elec-trical analog circuit. It includes the electrical, the mechanical andthe flow-dynamic properties of the actuator valve. The actuatorvalve concept is then simulated, from which a prototype can beconstructed. The active silencer has been tested on a cold en-gine simulator. This device generates realistic exhaust noise withthe associated gas flow using compressed air. The silencer canattenuate pulsations from engines at very low revolution speed,without passive elements preconnected between the engine and


the active silencer. This is not possible using loudspeaker basedactive silencers.


Active Structural Acoustic Control of Repetitive ImpactNoiseGregory Pinte, Rene Boonen, Wim Desmet, Paul SasDepartment of Mechanical Engineering, K.U.LeuvenIndustrial machines, which generate structure-borne impactnoise, often produce noise levels exceeding the limiting levels,demanded by the regulations for noise emission. Until today, theresearch on active control focuses on harmonic noise. This pa-per presents the possibilities of active structural acoustic controlof transient noise, produced by an impact excitation. The pre-sented research focuses on the development of feedback con-trol algorithms. A linear time-invariant feedback controller wasdeveloped to drive the structural actuator. The performance ofthis time-invariant controller is limited for several reasons: time-variance of the controlled system, limited controller bandwidth,non-linearities,... However, when the transient noise consists ofsuccessive impacts that exhibit a repetitive character, it is pos-sible to extend the developed time-invariant feedback controllerwith a learning behaviour, based on the additional informationabout the repetitiveness. As test case, a thick plate, excited by ahammer, is considered. The goal of the research is to reduce thestructural transient noise, generated by a hammer impact on theplate, by applying control forces on the plate. An accelerometermeasures the generated plate vibrations. This signal is sent tothe input of the controller, which drives a structural actuator. Ateach impact, the residual vibrations measured by the accelerom-eter, which cannot be controlled despite the action of the feed-back controller, are measured and stored in memory. At the nextimpact, the control signal for the structural actuator is adapted onthe basis of the residual error at the previous impacts, such thatthe radiated noise is reduced.


Design Optimisation of Active Constrained LayersHélène Illaire, Wolfgang KroppDepartment of Applied AcousticsIn Active Constrained Layer (ACL) treatments, a layer of vis-coelastic material is bonded to the host structure and constrainedby an actuator. Several mechanisms simultaneously damp vi-brations in ACL treatments, and an approach to quantify thesedamping mechanisms has been proposed [1]. A simple model ofa beam treated with ACL, which allows analytical investigations


of the damping mechanisms of ACL treatment, has also beendeveloped recently [2]. The objective of this paper is to under-stand how to optimise the design of ACL treatments, using thetools mentioned above. The influence of the shear modulus ofthe viscoelastic layer on the amplitude of the control voltage andon the robustness of the control is investigated. A comparisonbetween the conventional ACL configuration and the separatedactive-passive configuration, where an actuator and a passiveconstrained layer are separately bonded to the beam, is carriedout. A control law optimising the efficiency of the ACL treatment isproposed. [1] H. Illaire and W. Kropp, Quantification of dampingmechanisms of active constrained layer treatments, to be pub-lished in the Journal of Sound and Vibration. [2] H. Illaire, W.Kropp and B. Mace, A phenomenological model of active con-strained layers, in preparation.


Vibration Reduction of a Car Component by a Semi-PassivePiezoelectric ConceptLothar Gaul, Oliver Fein, Alexander SiefertInstitut A für Mechanik, Universität StuttgartLightweight structural design is often accompanied with a reduc-tion in structural stiffness. This can result in an increase of struc-tural vibrations. Viscoelastic damping layers can be efficientlyapplied to reduce these unwanted vibrations. However, such ameasure adds significant mass per area to the structure. Alter-natively, a semi-passive concept, realized by piezoceramics withan impedance in parallel, can be employed. This measure isalso known as ’shunted piezo technique’. The paper at hand in-vestigates the implementation of the semi-passive technique to ahood of a car. Piezoceramic patches (PZT) are applied at posi-tions, which yield high strain energy. A passive electrical network(PEN) is implemented and connected to the electrodes of all PZTcomponents. The resulting damping capability is similar to that ofviscoelastic material. Thus, the generated electrical energy ispartially dissipated as heat. By shifting the resistor value of thePEN the dissipated energy can be maximized. The modal pa-rameters of the car structure are determined from experimentalmodal analysis. Cubic splines are used to interpolate the result-ing eigenforms to allow for continuous differentiation in order todetermine the strain distribution. The positions of the PZTs areoptimized by taking into account the ratio of strain energy of allPZTs to the total strain energy. Finally, experiments are con-ducted to investigate this concept; structural response with semi-passive damping is compared to the response without.



Developing a Guideline on Active Vibration IsolationRolf Schirmacher, Roland KappelMüller-BBM GmbHActive Vibration Isolation moved onwards from a laboratory cu-riosity to state of the art technology during the last years. Todayit is used mainly for demanding applications where appropriateisolation is difficult to achieve by passive means. In addition,broader applications are under investigation and a common in-terest in the technology from an application point of view can befound. While there are guidelines and standards on passive vi-bration isolation (e.g. DIN EN 1299, VDI 2062), there are cur-rently no such documents for active systems. This lead to effortsto support designers, manufactureres and users of active vibra-tion isolation systems by a VDI guideline. This guideline shouldgive a basic understanding of active vibration isolation and definesome coherent terminology. It should give practical advice for thedesign of active vibration isolation. To support co-operation andinformation exchange, it should give hints for necessary informa-tion for the specification of an active vibration isolation systemand its components and also for test and measurement proce-dures. The current state of the comittee work will be presented.A special focus will be with the specification and test and mea-surement procedure topics.

Tu. 15:50 Tivoli 2 Non linear acoustics

Elastic Nonlinearity of Soft Solids Using Transient Elastog-raphyStefan Catheline, Jean-Luc Gennisson, Xavier Jacob,Christophe Barriere, Daniel Royer, Mathias FinkESPCI - LOAIf nonlinearity has long been studied in metals, crystals or rocks,almost no experimental works is found in the literature concerningsoft tissues. Thanks to the ultrafast scanner, we present in thispaper an overview of three transient elastography experimentsthat quantify the nonlinear behavior of a soft tissue phantom. Inthe first one, a static stress is applied on a phantom. The changeon the shear wave speed characterizes the nonlinear elastic Lan-dau moduli. The surprising difference found between these con-stants are thought to be closely related to the huge differencebetween the linear Lamé coefficients (l >> µ). It is the acous-toelasticity experiment. In the second one, we present the firstexperimental observation of a shock shear wave. The very weakYoung’s modulus of the tissue phantom allows one to generateplane shear wave with a Mach number as high as unity. In this


extreme configuration, the agreement with the theoretical predic-tion of the modified Burgers equation is remarkable. It is thefinite-amplitude shear wave experiment. At last, the interactionbetween two plane transverse waves with frequencies w1 andw2 is carefully studied. Harmonics are created during the propa-gation at the frequencies (3w1, 3w2, w1+2w2, w1-2w2, w2+2w1,w2-2w1). It is the parametric interaction experiment. This set ofthree experiments involves plane transverse waves. The feasibil-ity of measuring the nonlinear elastic coefficient with non planeshear wave is discussed in the last section.


Stationary and quasi-stationary solutions of the Burgers-type equationsMikhail Averianov, Marina Basova, Vera KhokhlovaDepartment of Acoustics, Physics Faculty, Moscow State Univer-sityNonlinear acoustic models based on the Burgers-type evolutionequations have been widely used in medical applications, geo-physics, and nonlinear diagnostics. Various frequency depen-dence of absorption, typical for media with complex internal struc-ture, has a strong effect on nonlinear wave propagation. Artificialabsorption is also used in numerical simulations of shock wavesand may result in nonphysical effects. An exact solution in theform of the stationary shock wave or quasi-stationary periodicwave can be obtained for the Burgers equation or nonlinear evo-lution equation with a relaxation term. However, in most casesnumerical simulations are necessary. The solutions of the Burg-ers type equations with the absorption governed by the second,forth, or sixth order derivatives, are considered in this work for aninitially step-like signal or harmonic wave. Stationary solutions inthe form of the shock wave and quasi-stationary solutions in theform of the periodic sawtooth-like wave are obtained numerically.Nonlinear waveform and spectrum evolution, shock formation, aswell as the intensity and total energy absorption are investigatedfor the periodic wave. Shock front fine structure is studied andcompared for various absorption terms. It is shown that in con-trast to the smooth hyperbolic tangent shape of the shock front incase of the classical Burgers equation, oscillatory behavior be-yond the shock is observed for the modified absorption governedby the forth or sixth order derivatives. Specific values of the di-mensionless absorption coefficient are found, that correspondsto the equal width of the shock front in all three cases.



Symmetry of Nonlinear Acoustics Equations Using GroupTheoretic Methods : a Signal Processing Tool for ExtractingJudicious Physical VariablesSerge Dos SantosGIP Ultrasons/ LUSSIThe concept of symmetry of differential equation seems to be-come a powerful tool for the understanding of nonlinear equa-tions. It is already used in various fields such as optics (NonlinearSchrödinger Equation) and fluid mechanics (Burgers). Symme-tries of nonlinear equations can induce transformations of theseequations into simpler ones introducing judicious variables im-plicitly related to physical invariants. In Acoustics, KZK equationis used for diffracted fields modelization propagating in nonlinearand attenuating media: hydroacoustics, medicine, biological tis-sue characterization and NDT. When attenuation is neglected,KZK becomes KZ for which Tjotta has found, using judicioustransformations, a class of exact solutions[1]. In order to find(and to generalize to whatever nonlinear problem) the physicalorigin of transformations proposed by Tjotta, we have applied aone-parameter Lie group transformation to the KZ equation in or-der to extract symmetries. We propose to describe the methodand present the extracted properties: existence of implicit solu-tions, explicit dependence versus the axial coordinate which isthe consequence of the far field diffraction, and the contributionof the ’nonlinear retarded time’. Already done in acoustic diffu-sion, the use of symmetries related to Lie groups leads to a sim-plification of nonlinear problems. One of the signal processingfruitful applications consists in building some particular initial con-ditions of excitation (related to well defined symmetries) leadingto solutions easily measurable using suitable nonlinear acousticsexperiments. [1] J.N. Tjotta. A class of exact solutions of theKhokhlov-Zabolotskaya equation. Acoust. Phys.,39(5):507-508,1993.


Quantitative Measurements of Ultrasonic Shock Waves Us-ing a Standard Optical InterferometerChristophe Barriere, Gabriel Montaldo, Daniel Royer, MathiasFinkESPCI - LOAIn order to measure acoustic shock waves generating pressuresof some tens of MPa in water, an ideal sensor has to be cali-brated, wide-band and sufficiently robust to support acoustic cav-itation. We measure high intensity ultrasonic displacements and


shock waves in water, using the phase modulation of an opti-cal beam reflected from a thin immersed membrane materialisingmoving particles. With a digital demodulation process, a 4.5-µmultrasonic transient displacement (corresponding to a 21.5-MPaacoustic pressure in water) has been measured with a standardheterodyne interferometer. Results are in good agreement withthose given by an hydrophone designed to measure high pres-sure wave. This sensitive optical method provides absolute mea-surements with a 50-µm lateral resolution, in a large bandwidth(from 20 kHz to 50 MHz). If the low cost membrane used in theexperimental set-up is damaged by the acoustic cavitation, it canbe replaced very easily, without changing the calibration factorof the interferometer. The maximum measurable displacementis limited by the frequency bandwidth of the instrument. Sincethe photodiode cuts off frequencies higher than 120 MHz, theinterferometer is able to measure 22-MPa peak acoustic pres-sures in water. This performance can be improved by increas-ing the Bragg cell frequency, to obtain a wider bandwidth. Weare now conceiving an interferometer working at 140-MHz carrierfrequency, to measure pressures up to 45 MPa.


Luxemburg-Gorky Effect in a Granular Medium: ProbingPerturbations of the Material State via Cross-Modulation ofElastic WavesVladimir Zaitsev, Veniamin Nazarov, Vincent Tournat,Vitali Gusev, Bernard CastagnèdeLaboratoire de Physique de l’Etat Condensé, UMR- CNRS 6087,Université du MaineThe nonlinear effect of amplitude modulation of a weaker sinu-soidal seismo-acoustic wave under the action of another strongerstep-wise modulated wave was reported in [1] for a sandy soil.Recently a related effect of transfer of the modulation spectrumfrom an intensive elastic wave to a probe one with different car-rier frequency was observed in resonant-type experiments insolid samples containing cracks [2]. This nonlinear effect is aclose elastic-wave analog of the similar phenomenon known asthe Luxemburg-Gorky effect for cross-modulation of radio-wavesin ionosphere. We report here observations of acoustic effects(self-action and cross-modulation) in a granular medium, whichdemonstrates the universality of the phenomena. Amplitude de-pendencies for the fundumental and induced modulation side-lobes of the probe wave have been studied. Furthermore, we ob-served complementary variability of the sidelobes and the probewave amplitude at the fundamental frequency under the action


on the medium of short ”seismic events” produced by an addi-tional shaker. The resultant transient variations in the amplitudeof the modulation sidelobes exceeded normally by an order ofmagnitude the complementary variations in the signal amplitudeat the fundamental frequency (the latter variations being oftenhardly noticeable). The revealed high sensitivity of the cross-modulation sidelobes to slight variations in the stress state of thematerial opens possibilities for efficient diagnostic applications ofthe effect in laboratory and in field conditions. 1. A.L. Bagmet,V.E. Nazarov, et al., Doklady Earth Sciences, 346 (1996) 135. 2.V. Zaitsev, V. Gusev, B.Castagnede, Phys. Rev. Lett., 89 (2002),105502.


Damage Characterisation and Structural Health Monitoringby Means of Nonlinear AcousticsMourad Bentahar, Rachid Elguerjouma, Thomas Monnier, Lu-cien Deville, Jean Claude BabouxInsa de Lyon- GemppmThis work is devoted to damage characterisation and structuralhealth monitoring of polymer composites and concrete. For cylin-drical concrete bars damaged in compression and thin compositeplates damaged in three points bending, we have used a nonlin-ear ultrasonic method based on the change of a resonance modefrequency. Compared with their initial states, damaged materialsare characterised by a resonance frequency shift as function ofthe excitation level. For a given value of the excitation level wehave performed upward and downward frequency sweepings andhave seen hysteresis loops that did not exist in the intact state.We have also submitted the material to a high excitation leveland have followed the forced variation of the frequency versustime ”fast dynamics” as well as the frequency recovery ”slow dy-namics” that changes as the logarithm of time. Fast and slowdynamics are correlated to the deterioration state of the materialand are found to be very sensitive damage indicators. In orderto monitor the material’s health along the damage process, thefrequency shift is compared to mechanical damage parametersand acoustic emission. A good correlation has been found. Ourresults confirm the efficacy of the nonlinear acoustical approachthat could enrich materials nondestructive testing field.



Nonlinear Scholte WavesAndreas Mayer, Alexander KovalevSiemens VDO Automotive AGNonlinear acoustic waves are considered that are guided at theinterface between a solid and a fluid with a compressibility muchhigher than that of the solid. It is shown that their waveform evolu-tion in the fluid is governed by the two-dimensional Zabolotskaya-Khokhlov (ZK) equation with a linear boundary condition deter-mined by the acoustic mismatch between fluid and solid. Twoevolution equations used for the interpretation of recent exper-iments are derived as two different limiting cases of the ZKequation with the corresponding boundary condition at the inter-face. The existence of solitary waves is predicted for the case ofScholte waves becoming dispersive due to inhomogeneity of thesolid. The depth profiles of such solitary interface waves and ofcorresponding stationary periodic waves are investigated.


Interaction of counter-propagating waves in resonant rodscomposed of materials with hysteretic quadratic nonlinear-ityVitali GusevLaboratoire de Physique de l’Etat Condensé, UMR- CNRS 6087,Université du MaineAn ordinary integro-differential equation for the profile of theacoustic wave in a resonant rode, composed of a material withhysteretic quadratic nonlinearity, is derived. It explicitly takesinto account the interaction of the counter-propagating acous-tic waves. It is demonstrated that in contradiction with simple-minded intuition this interaction suppresses the nonlinear phe-nomena. In particular the maximum vibration amplitude pre-dicted by this theory is higher and the shift of the resonancepeak is smaller in comparison with the case when the interactionof the counter-propagating waves is neglected. The interactiondue to hysteretic quadratic nonlinearity amplifies both counter-propagating waves and also suppresses to some extent softeningof the material with increasing wave amplitude.


Tu. 8:30 Gutenberg Numerical methods in acoustics I

On the Velocity Distribution at the Interface of Horn Driverand HornMichael Makarski, Gottfried BehlerInstitute of Technical AcousticsFor numerical simulations (boundary element method) of horns,the distribution of velocity or pressure at the horn throat is re-quired as boundary condition. For frequencies below the firsthigher order mode, a plane wave approach is assumed as cor-rect. Usually, the plane wave approach is also used for the higherfrequencies as the shape of the wave front radiated by the horndriver is not known. This can cause an error in simulation re-sults, e.g. the simulated directivity may deviate from a measureddirectivity. To improve the accuracy of numerical simulations, aspecific distribution of velocity has to be used. To achieve moreinformation about the required pressure and velocity conditions,the pressure distribution of different horn driver/horn combina-tions is measured at the interface between horn driver and horn.It is investigated if a wave front can be synthesized from thesemeasurements that allows a more precise description of the in-terface horn driver/horn. Measurements and simulations usingdifferent velocity distributions are compared in order to verify thismethod.


Speeding-up acoustic predictionsM. Tournour, C. F. Mcculloch, Oscar Flores SantiagoLMS Deutschland GmbHFinite element and especially boundary element methods foracoustic and vibro-acoustic predictions bring many benefits, inparticular accuracy of the predictions, but they have traditionallysuffered the penalty of long calculation times and large comput-ing resource requirements, to achieve these results. This paperpresents several recent developments which speed up the solu-tion of finite element and boundary element acoustic models, withparticular emphasis on BE models for acoustic radiation. Themethods are based on Acoustic Transfer Vectors, Padé methods,domain decomposition and iterative solvers. These technologiesmake accurate acoustic predictions timely and effective: calcu-lations can be accelerated by one or even two orders of mag-nitude. They tackle a wide range of applications ranging fromengine acoustics to interior acoustics and enable the users todesign practical solutions and effectively reduce time-to-marketand development costs. The paper explains the methodologiesand their implementation in practical software, and presents theresults of several case studies and benchmarks.



Patch Transfer Function (PTF): a substructuring approachfor linear acousticsMorvan Ouisse, Laurent Maxit, Christian Cacciolati, Jean-LouisGuyaderLab. Vibrations Acoustique, INSA Lyon - Bât. 303For industrial structures, large acoustics problems like noise ra-diated by cars are very difficult to solve using classical methodslike full BEM, because of the complexity of the structure. ThePTF approach considers several acoustic subsystems, which areanalyzed separately, considering each coupling area as a rigidsurface, which is divided in elements called patches. For thesecalculations, any available method (FEM, BEMoe) can be used inorder to build a database of transfer functions between sourcesand patches, which are acoustic impedance transfer functions.Then, continuity relations can be written on the interface in orderto couple the subdomains: this approach is close to the mobilityand impedance concepts which are widely used in mechanics.After the description of the method, some results concerning theconvergence of the method are shown, concerning in particularthe interface mesh size, which should be smaller than the halfwavelength. Then, some results on an automotive structure arepresented: the noise emitted by an engine through apertures ofa car is estimated and compared with experiments.


Numerical Calculation of Acoustic Scattering From SimpleStructures Using the Multiparametric Gradient MethodEdgar SchmidtkeForschungsanstalt der Bundeswehr für Wasserschall und Geo-physikUnder certain circumstances the Kirchhoff-Helmholtz-integralequation for submerged scatterers can be formulated as aFredholm-equation of the second kind. If the scatterer is modeledas a polyhedron and all functions are assumed to be constant onevery facet, the Fredholm-equation can be written as a system oflinear equations with dimension D equal to the number of facets.It is planned to calculate structures up to D=10ˆ 4...10ˆ 6, so avery fast solver is necessary. The new multiparametric gradientmethod [1] will be presented as an extension to already estab-lished gradient methods. Calculations of scattering from sphereswith surface impedance and from a ’Cat’s Eye’ will be comparedwith analytical solutions and with results of other numerical meth-ods (FIELD [2]) with respect to accuracy and speed. [1] I. Nis-sen, Multiparametrische Gradientenverfahren, Ph.D. Thesis, Kiel,


1997 [2] M. Ochmann, A. Homm and J. Ehrlich, Numerical Cal-culation of Acoustic Scattering from a Finite Cylinder with LocallyVarying Surface Impedance, A. Acustica 89, 14-20 (2003)


A boundary element simulation tool for exterior acousticalproblemsMartin Ochmann, Alexander OsetrovTechnische Fachhochschule BerlinThe numerical prediction of sound fields radiated or scat-tered from complex shaped structures into the three-dimensionalspace can be used as a basis for the optimization of noise reduc-tion methods. Especially, the boundary element method (BEM)combined with iterative solvers is a very efficient tool for per-forming such numerical simulations. For this reason, a simula-tion tool based on the boundary element method is developedfor the analysis of acoustical radiation as well as of scatteringproblems. For the solution of the corresponding system of linearequations direct and iterative solvers are implemented. To over-come the computational difficulties at the ”forbidden” frequencies,two methods are used: the combined integral equation formu-lation (CHIEF) and the combination with the differentiated inte-gral equation (Burton and Miller formulation). The efficiency ofboth regularization methods are investigated depending on thefrequency range considered. The capacity of the BE simulationtool will be demonstrated by applying it to the calculation of soundradiation from specially selected vibrating structures. In addition,the scattering from point sources located between an idealizedtyre and a road surface is calculated for modelling the so-calledhorn effect.


Fast BEM-FEM Coupling for the Simulation of Acoustic-Structure InteractionMatthias Fischer, Lothar GaulInstitut A für Mechanik, Universität StuttgartBEM-FEM coupling is widely used for the simulation of the inter-action between structural vibrations and radiated acoustic fields.Employing the FEM for the structure and the BEM for the acousticfield, exploits the specific advantages of the two methods. How-ever, the efficiency of BEM-FEM simulations suffers from the fullypopulated BEM matrices. In recent years, fast algorithms havebeen developed that allow a sparse representation of the BEMsystems. In the presented paper, the fast multipole BEM is out-lined and a coupling scheme is developed that accounts for theproperties of the fast BEM. The coupling algorithm is based on


Lagrange multipliers and provides high flexibility in the choice ofdiscretizations. For the solution of the resulting saddle point prob-lem, an approximate Uzawa algorithm is employed. Simulationsin the medium frequency range require an adapted precondition-ing of the system. Numerical examples show the performance ofa multilevel preconditioner as well as of the entire coupling algo-rithm.


Representing Outdoor Sound Propagation Effects with aBEM ModelSebastian Hampel, Sabine Langer, Heinz AntesInstitut für Angewandte Mechanik, TU BraunschweigOutdoor sound propagation is influenced by numerous differentfactors. Among these the most important are: Geometric damp-ing, absorption of sound energy in the air and on the ground,acoustic shadow and diffraction effects and meteorological con-ditions such as wind and temperature conditions. To receive anapplicable prediction of the sound field or sound immission at cer-tain receiver positions without undertaking time-consuming andexpensive experiments, it is necessary to include those propaga-tion effects in a numerical simulation model. In acoustics, for infi-nite domains in particular, the Boundary Element Method (BEM)has established as a suitable and powerful numerical method.Therefore, it is shown how the important effects can be includedin a BEM model. Furthermore, the ability or possible limits torepresent these phenomena with BEM are investigated. Finally,BEM solutions for selected example problems are compared toeither analytical solution or other reference values.


Efficient Simulation of Sound Insulation in ArchitecturalAcousticsDirk Clasen, Sabine Langer, Martin SchanzInstitut für Angewandte Mechanik, TU BraunschweigSo far, damping mechanisms have not been used systematicallyin architectural acoustics and, thus, a great potential in improve-ment of sound insulation is lost. Due to this fact it is importantto analyze different damping mechanisms and their effects onsound transmission in buildings. To study them, beside mea-surements, numerical simulation techniques for sound transmis-sion are available. To numerically predict the sound insulationof a building a tool based on Finite Element and Boundary Ele-ment Method has been developed. Real world problems resultin very large systems which need an optimized implementationwith respect to storage and numerical efficiency. This is realized


using freely available numerical libraries which provide efficientroutines to treat sparse matrices and large scale linear equationsystems. They have been integrated to the program to reducememory usage and to speed up equation system solving. Hence,enormously larger problems can be handled now. Another ad-vantage is that theses libraries are extensively tested and providealmost error free code.


Combining Finite Element and SEA Approch in Vibroacous-tic AnalysisGerard BorelloInterACStatistical Energy Analysis (SEA) is a powerful approach for pre-dicting vibracoustic trends in the high frequency domain. Thismethod is nevertheless limited by the extensive use of analyticalrepresentation for computing SEA parameters and fails to provideaccurate results when structural complexity increases (car bod-ies, stiffer parts of structures...). Finite Element modelling (FE)can be involved in the predicting SEA scheme to provide morerealistic SEA parameters. Using inverse SEA techniques appliedto FE forced solutions, SEA model can be built from FE data andprovide accurate models for structure borne sound. This virtualSEA methodology will be demonstrated on examples taken forautomotive and aerospace industries.


Practical considerations of the acoustic FEM for higher fre-quenciesSteffen Petersen, Daniel Dreyer, Otto Von EstorffAUDI AGThe Finite Element Method (FEM) is an indispensable tool in to-day’s simulation tasks. It is at the core of any concept that at-tempts to reduce time-to-market and/or enforces virtual prototyp-ing in almost every engineering field. However, when simulat-ing time harmonic acoustics using the FEM, an efficient tool forbridging the ’mid-frequency gap’ is still missing. The lower fre-quency range is well covered through element-based methods,like domain- or boundary-integral based formulations. The higherfrequency range, in turn, benefits from the development of en-ergy averaging methods. However in between, the mode densityis too low to render the high-frequency methods effective, andthe FEM suffers with increasing wave number from the so-calledpollution effect. Several approaches exist, that attempt to extendthe element-based methods to the mid-frequency range. Thesegenerally rely on knowledge-based concepts, i.e. incorporating


a-priori-knowledge of the solution into the numerical method it-self. However, these concepts appear to still lack sufficient ma-turity for reliable and stable simulations. In this contribution, amore straightforward approach to tackle the pollution effect issuggested, namely through still relying on the conventional FEM,but including the latest developments and most efficient toolscurrently available. Studies concerning the best combination ofseveral polynomial shape function families, efficient solvers, andmeans to suppress pollution are presented.


A component study of the vibroacoustic damping of a non-baffled free plate partially covered with elastomer patchesLionel Zoghaib, Pierre-Olivier MatteiLMA CNRSThis work deals with a vibroacoustic numerical and experimen-tal study of a suspended free thin plate which has been partiallycovered with polymer patches. The aim of the investigation isto develop a model of the acoustical and mechanical dampingcomponents for an optimization of the patches location for noisereduction purposes. The patches are thin double-layer elas-tomer/aluminum laminae whose dissipative influence has beenstudied in different locations of the aluminum plate. The analysisis based on a viscoelastic incompressible 3D finite element for-mulation of the rubber layer together with a Kirchhoff-Love plateelement model of the metal layers. The differential system ofequations that governs both the displacement of the structureand the acoustic pressure is transformed into one single integro-differential equation of the displacement. The acoustic Greenfunction of the spatial configuration is computed by a direct BEMusing a double-layer potential. The solution is expressed as aseries of the resonance modes. The resonance modes are com-puted using a perturbation expansion with respect to a small pa-rameter associated to the light fluid approximation. The numer-ical model clearly distinguishes the viscoelastic damping fromthe damping associated to the fluid-structure coupling. In ad-dition modal analysis with a non-contacting method is achievedby means of a loudspeaker and a laser-beam measurement ap-paratus. Comparisons between the numerical computations ofthe damping and the corresponding measured one show the ef-ficiency of the method.



On the use of a novel Wave Based Method for the DynamicAnalysis of Flat Plate AssembliesCaroline Vanmaele, Bert Pluymers, Wim Desmet, Dirk Vande-pitte, Paul SasDepartment of Mechanical Engineering, K.U.LeuvenIn recent years, the vibro-acoustic behaviour of a product has be-come a design criterion of growing importance. This behaviouris mainly determined by the steady-state dynamic deformationsin the mechanical structure of the product. Commonly, the fi-nite element method is used to predict the dynamic behaviourof structures. This method expands the dynamic field variables,within each element, in terms of local, non-exact shape functions.As a result, the size of the model becomes prohibitively large forincreasing frequencies, thereby leading to a practical frequencylimit. The newly developed wave based prediction technique,based on the indirect Trefftz method, expands the field variablesin terms of global wave function expansions, which exactly sat-isfy the governing dynamic equations. The wave based methodshows to be computationally more efficient, and will consequentlybe applicable also for higher frequencies. Although the structural-dynamic calculations are computationally the most demandingpart in a vibro-acoustic problem, until now the research focusedmostly on acoustic systems. Current research extends the ap-plicability of the wave base method towards three-dimensionalstructural-dynamic applications. This paper discusses the devel-opment of the wave based method for analysing the behaviour ofan assembly of flat plates, coupled at arbitrary angles. Numer-ical validations confirm that the wave based method achieves ahigh accuracy with substantially smaller models in comparisonwith the finite element method.


Application of a Novel Wave Based Prediction Technique forAcoustic Cavity AnalysisBert Pluymers, Caroline Vanmaele, Ravish Masti, Wim Desmet,Dirk Vandepitte, Paul Sas, Eike BrechlinDepartment of Mechanical Engineering, K.U.LeuvenVehicle interior acoustics has become an important design crite-rion. Both legal restrictions and the growing demand for comfort,force car manufacturers to optimize the vibro-acoustic behavior oftheir products. The tendency to minimize the number of physicalprototypes and to reduce the overall development cost and time,as well as the high performance of modern computer resources,clear the path for numerical prediction techniques to drive the


noise, vibration and harshness optimization. The most commonlyused numerical prediction techniques for vibro-acoustics are el-ement based methods, such as the finite element method andthe boundary element method, and the statistical energy analy-sis method. However, element based methods are only applica-ble in the lower frequency range and the statistical energy anal-ysis method in the higher frequency range, leaving a frequencyband, which is called the mid-frequency gap, for which no effec-tive prediction technique is available at this moment. The wavebased prediction technique is one of the techniques that exhibitpotential to narrow this frequency gap. Like the element basedmethods, the wave based prediction technique is a deterministictechnique, which is however computationally more efficient andthus suited for the mid-frequency range. This paper discussesthe application of the wave based prediction technique for thethree-dimensional acoustic analysis of a car-like cavity. A com-parison with corresponding finite element discretizations as wellas an experimental validation are presented with special focus onthe convergence rate and computational efforts involved with thenovel technique.


Transient Sound Generation of a Plate Coupled to an Acous-tic CavityPierre-Olivier Mattei, Ulf KristiansenLMA CNRSThe sound radiated into a cavity by the surrounding walls de-pends on several factors. The signal type, wall construction, cav-ity geometry and damping are of the most important. In this paperresults that illustrate many of the basic features of vibro-acousticcoupling in the transient regime are presented. One of the aimsis to describe the response of the fluid-loaded plate coupled to arigid cavity when it is excited by a Ricker wavelet and to see theinfluence of the excitation on the response of system. An othergoal is to compare results given by two calculation methods. Thefirst uses an explicit finite difference scheme to discretize the gov-erning equations in space and time. The other uses an analytictechnique based on a series expansion into resonance modes.These modes, here computed using perturbation expansion toaccount for small damping and loading, correspond to the freeoscillations of the plate-cavity system. The results from the twomodels are in good correspondence. Both models show that theefficiency by which the plate radiates sound into the room can ingeneral qualitatively be explained by the speed of the Fourier fre-quency components of the impulse type signal. Subsonic phase


velocities generate a near acoustic field, and only transfer acous-tic energy to the room from the region close to the plate bound-aries. For supersonic bending wave speeds energy is transferredto the room all along the trajectory.


Comparison of a Deterministic and a Genetic Algorithm ap-plied to Structural Acoustic OptimizationJoachim BösFraunhofer Institute for Structural Durability LBFBoth a deterministic (local) and a stochastic (global) optimizationalgorithm are used to optimize the wall thickness distribution ofa model structure such that the difference between two specifiednatural frequencies is maximized, subject to the following con-straints: Neither the vibrational level nor the structural mass areallowed to increase. Powell’s COBYLA algorithm, which is a se-quential trust-region method that employs linear approximationsto the objective and constraint functions, is used as the deter-ministic algorithm. A specific implementation of a genetic algo-rithm, namely Charbonneau’s PIKAIA algorithm, serves as thestochastic algorithm. The model structure consists of two rectan-gular steel plates with an initial wall thickness of 4 mm, joined atan angle of 90 degrees. The structure is excited by a harmonicforce (0-3000 Hz). For the initial configuration, the differencebetween the two natural frequencies under consideration is 19Hz. COBYLA takes about 11000 function evaluations to meet itsconvergence criterion, and the final design shows an increasedfrequency difference of 485 Hz (+2450%). PIKAIA has no con-vergence criterion and is therefore stopped after 50000 functionevaluations. At this point, the frequency difference is increasedto 547 Hz (+2779%). Obviously, COBYLA finds only a local opti-mum, whereas PIKAIA locates the global one or at least a signif-icantly better local optimum. However, PIKAIA takes almost fourtimes more function evaluations to obtain the final design.


Energy residuals for localization of structural areas inducinghypersensitive behaviorMorvan Ouisse, Jean-Louis GuyaderLab. Vibrations Acoustique, INSA Lyon - Bât. 303This paper describes a method allowing one to localize struc-tural areas inducing hypersensitive vibrating behavior: with a verylow calculation cost, the use of energy residual in fem post pro-cessing can be very efficient to detect the zones in which smallchanges can induce large dispersions on responses. The prin-ciple of the method is presented here, including a comparison


between some energy residuals, in term of efficiency and local-ization properties.


Power Transmission Coefficients for Generic StructuralJunctionsEnnes SarradjGesellschaft fuer Akustikforschung Dresden m.b.H.A number of numerical methods exist for the prediction of high-frequency structure-borne sound. In particular statistical en-ergy analysis, energy finite element methods and smooth en-ergy methods are used. In all these methods, the transmissionacross structural junctions is characterised by power transmis-sion coefficients. Thus, the results of the calculation dependon the exact prediction of these coefficients. In the paper, ageneric approach for the calculation of power transmission coef-ficients is presented. Included in this approach are several typesof connections: line-connected plates, point-connected beams,point-connected-plates and point connections between beamsand line-connected plates. The theory and numerical procedureapplied for these connection types is outlined and some exampleresults are shown.


Acoustical energy diffracted around a buildingEmeline Reboul, Joël Perret-Liaudet, Alain Le BotEcole Centrale de LyonAcoustical diffraction is a current phenomena which occurs whensound waves hit obstacles: this phenomenon brings acousticalenergy into shadow areas that are prevented from direct inci-dence. It has been widely studied, in particular by means of theGeometrical Theory of Diffraction (GTD) developped by Keller.This theory extends geometrical acoustics to diffraction phenom-ena and proposes frequency-domain formulations for diffractedrays, asymptotically valid at high frequencies. This paper con-cerns the study of diffraction by means of an original methodbased on energy considerations. This method relies on the equa-tion of the energy radiative transfer, and is well-suited for highfrequency applications. This method has given rise to the de-velopment of a specific software called CeReS. In the proposedapproach, diffraction phenomena is treated by introducing diffrac-tion sources whose amplitudes are calculated by applying thepower balance between all acoustical sources. It appears to beparticularly well-suited for multiple diffraction case as all ordersof diffraction are simultaneously taken into account. The methodis applied in the case of diffraction around a building near a road.


In this context, diffraction is a major phenomena responsible fornoise in the backyard of the building. Results obtained with themethod are compared to reference one: enough good agreementon sound pressure level is observed all around the building.

Tu. 8:30 Kleber Hydroacoustics, underwater acoustics

Enhanced Simulation of Hydroacoustics in Flexible Struc-tures by Substructuring and Model ReductionMatthias Maess, Lothar GaulInstitut A für Mechanik, Universität StuttgartThe paper discusses aspects of simulating hydroacoustic vibra-tions and wave propagation of compressible fluids enclosed inflexible containers such as pipe assemblies or tanks. The two-field simulation models are coupled at fluid-structure interfaces.A coupled finite element model of substructure segments con-taining the fluid is used for modal and transient analysis. Thedynamic equations using the acoustic pressure as field variablein the fluid render both non-symmetric mass and stiffness matri-ces due to the FSI-coupling. However it is possible to achievea symmetric representation by introducing the velocity potentialas field variable. The existing matrices are transformed into asymmetric system representing the coupling by a damping-likematrix. Based on these two formulations, model reduction andcomponent mode synthesis are performed for FSI-coupled sub-structures. Hereby, the coupling interface between substructuresdoes not only represent a structural interface but also containsa hydroacoustical partition. Therefore, implicit scleronomic con-straints hold for both the nodal displacements and the nodal pres-sures at the interface, and they are used to generate transforma-tion matrices for the coupling. The substructures are reducedwith respect to their interface degrees of freedom mainly to guar-antee sufficient accuracy for the coupled model. The model re-duction bases for the coupled system are obtained from the un-coupled fluid and structure domains (indirect model reduction).Results for vibrations and wave propagation in composed FSI-coupled piping systems are presented.


Hydrodynamic Pressure on Multiple Vertical Cylinders in aCompressible FluidOtto Von Estorff, Marian Markiewicz, Olgierd ZaleskiTechnische Universität Hamburg-HarburgThe numerical study of the acoustic interaction among severalobstacles in a compressible fluid is a challenging task, especiallyif the amount of interacting bodies is given by a two-digit num-ber. Typical examples of such systems include the tube bundles


in heat exchangers, underwater pipelines, arrays of cylinders inseabed offshore structures, and mega-float structures. Due tothe complexity of these systems, the standard Finite Element orBoundary Element codes are practically inapplicable. The acous-tic pressure and the associated forces on such structure assem-blies can effectively be predicted by using the so-called ”exactalgebraic method”. The methodology belongs to the group ofnumerical-analytical methods. The numerical part includes thecomputation of the so-called diffraction matrices for all membersof the assembly and it can be accomplished by using any com-mercial FE or BE code. The kernel of the method is the solution ofthe interaction problem which is formulated analytically using anexpansion of the wave fields radiated and scattered by each sys-tem member into elementary incoming wave components. Thetotal incoming wave and the radiated wave by each member arethen combined using diffraction matrices. This yields the finalsystem of linear algebraic equations for the unknown expansioncoefficients of the total interaction problem. After a general pre-sentation of the method, some computational examples for thearrays of vertical cylinders in water of constant depth will be pre-sented.


Benchmark solutions for scattering problems in acousticsBernhard Schwarz-RöhrCarl von Ossietzky Universität OldenburgNumerical solutions for scattering in acoustics are usually ob-tained by methods of finite element or boundary element type.Beeing quite versatile on the hand, these methods do not pro-vide estimates for the accuracy of the solution. Thus analyticalsolutions for not to simple testcases are of major importance. Inthis paper, the scattering by a hollow sphere with thin, rigid wallsand a hole linking inner and outer space is considered. Solutionsbased on eigenfunction expansions are presented, the stabilityand accuracy of these solutions is discussed.


Transform methods for horizontally layered isotropic andanisotropic media with obstaclesHolger WaubkeInstitut für Schallforschung, öAWThe transform method has shown its advantages for media withregular boundaries. As long as the boundaries are parallel, ananalytic evaluation for every layer is possible in the transformeddomain. This model was already used to calculate Scholte wavesat the boundary between a water layer and an isotropic random,


or an orthotropic soil layer or a half space. Compatibility be-tween the boundaries leads to a matrix equation that is solvednumerically. Back transform is also done by numerically usinga fast Fourier transform instead of a Fourier integral transform.An extension to randomly varying material behaviour by meansof Parseval’s theorem and transformed finite elements was al-ready explained in prior presentations. This method can be usedfor obstacles also, but the idea is suited to global variations. Adifferent approach is the derivation of Green’s functions. Thisnormally needs a particular solution for an impact within a layer.This solution can be derived from the homogenous solution, if anaddition boundary in variable depth is introduced into the model.Impact loads for the generation of test functions are added atthe variable interface as external stresses. In an isotropic oranisotropic medium, dipole solutions with a well defined direc-tion are needed. This is done using impact loads with horizontaland vertical direction. The method is presented and possible re-ductions in the numerical efforts are explained.


Detection of objects buried in the seafloor with an Experi-mental Sediment SonarDieter Brecht, Harald PeineFWG KielWith the demonstrator system EXSESO (Experimental SedimentSonar) FWG investigates the detection and classification of ob-jects buried in the seafloor under realistic conditions. The testsites are located in the Baltic Sea near Kiel. Spheres and cylin-ders filled with concrete were used as targets. Most of them wereequipped with water jet facilities. These help the divers to burythe targets and keep the disturbed sediment volume rather small.Some of the objects are equipped with a transponder system,allowing to check the target position with high accuracy. Exper-imental Results of the Sea Trials are presented. This includesdetection results, display concepts, the fusion of high and lowfrequency information and the related signal processing tools.


Hydro acoustical range facilities in GermanyStefan SchaelWTD 71, AkustikzentrumDAGA 2004 Military requirements demand special properties oftheir equipment. Therefore the navy works out operational sce-narios to derive the possibly threat of their mission and ships. Inrespect to this prerequisite we define feasible maximum signa-ture levels of naval ships and boats placed in contracts agreed


by the ship yard. WTD 71 provides hydro acoustical ranges toperform measurements for investigating the acoustical behaviorof naval ships and boats and to control the fulfillment of the con-tracts. This talk will describe the underwater installation for deepwater and also for shallow water measurements, the proceduresof the performance and the analysis of the data processing. Be-sides measuring the target level it is also mandatory to verify thegenerating noise source. A brief overview will show results re-ceived by · a phase array · narrow band analysis · DEMON ·LOFAR The range facilities is constantly improved by the require-ment of new projects. U 212 will give an idea of how to preparethe acceptance test.


Freefield Measurements of Radiated and Structure BorneSound of a ShipVolkmar Nejedl, Jan Ehrlich, Christian KubaczykFWG KielThe radiated underwater sound of technical structures into thefar field is of widespread interest, especially for naval ships. Apart of the radiated field is caused by structure borne sound ex-cited by the ship’s vibrational sources (engines, pumps etc). Ac-tually, there is no reliable physical model that describes the rela-tion between source properties inside the ship and the radiatedsound into the far field. Therefore a concept for the identificationand quantification of the essential effects is needed. The paperdescribes the investigation concept and the experimental con-figuration for the simultaneous measurement of both, the struc-ture borne sound and the radiated sound of a ship. The trialswere carried out with the research vessel ’PLANET’ in the CelticSea. The structure borne sound was measured using up to 18accelerometers placed on several aggregates and frames alongthe ship. For the measurement of the radiated sound field anautonomous, buoyant vertical line array was used. In addition tothe ships sound sources, defined signals were generated by twoself mounted shakers. The evaluation of the experimental datafocusses on the identification of the dominating sound sourcesand their relations to the radiated field. Selected results as wellas essential problems will be discussed.



Predicting Very Low Frequency Underwater Radiated Noisefrom Full-Scale ShipsLayton GilroyDRDC AtlanticMethods for predicting fluid-structure interaction and underwa-ter radiated noise have been under development for a numberof years. For very low frequencies, a combined finite elementand boundary element technique is often used and such a sys-tem (AVAST) is available at DRDC Atlantic. While a variety ofstructures have been examined, the complete analysis of a full-scale vessel is still relatively rare. There is also a renewed con-cern to minimize the underwater radiated noise from commer-cial vessels and, in particular, fisheries research vessels. TheInternational Council for the Exploration of the Sea (ICES) hasissued recommendations for maximum radiated noise levels overa broad spectrum. This includes very low frequency (less than 50Hz) narrowband noise, which is not amenable to prediction withenergy-based or empirical methods. This paper will demonstratethe procedure for predicting the very low frequency radiated noisefrom a generic ship model with excitation provided by sample vi-brations measured on engine mounts. The analysis will proceedfrom a coarse MAESTRO model of the vessel, through to a finiteelement model where the loads will be applied and the naturalfrequencies calculated, to a radiated noise prediction using theAVAST software. The resulting prediction will be compared tothe ICES recommendations up to a frequency of about 50 Hz.The paper will also discuss the difficulties encountered in suchanalyses and make recommendations as to an appropriate wayahead.


Acoustic Tomography Experiment in the Lake of GenevaXavier FalourdEcole Polytechnique Fédérale de LausannePhysical limnology in lake Geneva tries to identify the dominantprocesses of transport and mixing which influence the water qual-ity of the lake. In order to achieve this, a nearly continuous ob-servation of the movements of the water masses and the devel-opment of the thermal stratification is required. By measuring thedifference in sound travel times in two directions between arraysof hydrophones, placed at the boundary of the lake, we can in-fer, using tomography inversions techniques, the stratification andhydrodynamic state at lake basin scale. The paper presents theresults of an experimentation carried out during the autumn 2003


in lake Geneva, between two linear arrays of four hydrophonesat thirteen-kilometre range. Binary Phase Shift Key signals (cen-tered 20 kHz) are examined every five minutes during a long-termperiod. Detected ray paths are discriminated in time and angleusing the MUSICAL method. From the two-way transmission, wederive the thermal stratification and the current velocity compo-nent during the experimentation. Finally, we derive from raw hy-drodynamic data the influence of the stratification perturbationson the acoustic propagation. The analysis of travel time pertur-bations shows the variability of the propagation path induced byinternal waves and other currents within the field of study duringthe experimentation.


Heterodyne and Time-gated Time-delay Spectrometry forAmplitude and Phase Calibration of Hydrophones up to 50MHzChristian Koch, Volker WilkensPhysikalisch Technische Bundesanstalt, FB 1.6 SchallTo date, primary and secondary hydrophone calibration tech-niques provide the amplitude of the hydrophone sensitivity of in-ternal standards or for a calibration service. In many applicationsprecise and reliable measurements are, however, impeded bythe non-ideal transfer characteristic of the hydrophone, and de-convolution procedures are necessary for data correction, whichrequires the complex sensitivity of the hydrophone being deter-mined. Two methods based on the principles of time-delay spec-trometry (TDS) are presented providing the complex hydrophonesensitivity up to 50 MHz. In the first technique heterodyning isused to ensure a fixed phase relation between transmitting andreceiving voltage at the ports of a network analyser. The secondmethod separates unwanted signals from the measurement infor-mation in the time domain using a fast-Fourier transform (FFT).To show the performance of the methods, several hydrophonesof membrane and needle type were investigated in different fre-quency ranges. The two reference hydrophones used were cali-brated before by a primary interferometry-based calibration tech-nique yielding the amplitude of the sensitivity. As a phase stan-dard an optical multilayer hydrophone was successfully employedshowing an extremely flat amplitude and phase response. Thus,absolute amplitude and phase values are obtained from the TDS-technique in a wide frequency range. To validate the new method,results were compared with those of interferometric calibration, ofa pulse calibration technique recently developed for hydrophoneswith small diameters and optical techniques, and of a hydrophone


model. The agreement is excellent in most cases and the dataprovide a basis for deconvolution correction procedures.

Tu. 16:50 Kleber Noise from leisure activities

Tendencies in the Worsening of Hearing Thresholds ofPupils with Regard to Leisure NoiseDetlef Schulz, Karin KünzelHochschule Mittweida (FH)There has been considerable literature over the past decade as-certaining a worsening of the hearing capability of young per-sons. Within the scope of a long-term-investigation we performedannual audiometric testing of pupils of 7th - 10th classes during3-4 years (longitudinal hearing study). This testing was supple-mented by a questionnaire regarding noise - relevant aspects ofthe behaviour in the leisure time (e.g. hobbies) and of the stateof health. Apart from an increase in attending discotheques nostrong alterations of the behaviour could be detected. Comparingespecially pupils of 8th - 10th and 9th - 10th classes of the samesamples a worsening of the hearing thresholds was found. Theaverage hearing thresholds of these samples increased signifi-cantly in the frequency range of 1 - 6 kHz and 14 - 16 kHz. Hintsfor specific patterns of hearing impairments and correlations withnoisy activities are discussed.


Untersuchungen zur Schallemission von FreizeitaktivitätenHans-Jörg EdererAkustik Bureau DresdenDas Sächsische Landesamt für Umwelt und Geologie hat2001/2002 ein Forschungs- und Entwicklungsprojekt unter demThema ’Sächsische Freizeitlärmstudie’ initiiert. Im Rahmendieser Studie waren Untersuchungen der Geräuschemissio-nen ausgewählter Freizeiteinrichtungen und Freizeitaktivitätendurchzuführen, sowie Berechnungsverfahren zur schalltechnis-chen Prognose der daraus resultierenden Geräuschimmissionenin der Nachbarschaft zu erarbeiten. Neben Freiluftkonzerten,Rummelplätzen und Volksfesten wurden unter anderem Anlagenfür Modellfahrzeuge und -flugzeuge, Hundedressurplätze, Aben-teuerspielplätze, ortsfeste Wasser skianlagen sowie Sommer-rodelbahnen untersucht. In dem Vortrag soll sowohl eine über-sicht über die gewonnenen Meßergebnisse ausgewählter Anla-gen gegeben als auch über die Probleme bei der Verifizierungberichtet werden.



Noise Exposure in KindergartensReimer PaulsenBIA - Berufsgenossenschaftliches Institut für ArbeitsschutzRating levels between 80 and 85 dB(A) (LAeq, 8h ) are not un-common at kindergarten workplaces. Such levels were approvedby measurements of the BIA. Peak levels up to 120 dB(C) weremeasured and, additionally a lot of impulsive noises (caused bychildren’s shouting or wooden furniture falling down) were ob-served. Especially when acoustic conditions are adverse (e.g.cause of absent acoustic ceilings) such high noise exposure canbe measured. Presenting these results the focus should be di-rected to the exigence of an adequate acoustic design of kinder-gartens. Maybe the implementation of the new EC directiveto protect employees at the workplace will produce the break-through. If the action levels of this directive are implemented, suit-able hearing protectors must be provided for kindergarten teach-ers.


Impact of acoustic quality in schools : from measurement toperceptive evaluationAline Barlet, Emmanuel MéridaEAPBx -GRECOThis paper deals with the evaluation of the acoustic quality ofnursery schools. These premises are rarely considered in termsof environment, particularly in acoustic terms. Nevertheless, dur-ing their stay, all the users, adults and children, could be con-fronted with unpleasant acoustical conditions. However, nurs-ery school environments play an important role in the youngchildren’s development of knowledge and sociability. In orderto know more about the relation between the children’s com-portment, the adults’ evaluation and the environment, it seemsessential to analyse the impact of acoustic on their reactions,notably by modifying the spaces. So, we realized a study infive nursery schools in Bordeaux, which represent a large archi-tectural diversity. We chose to work in particular spaces: theclassroom and the activity room [Louwerse C., Barlet A., Sémi-dor C., 2002]. Although the initial methodological approach wasmore global, in this article we want to focus our attention onlyon two phases. These phases were separated by a modificationof acoustical characteristics: a decrease of reverberation time.Each phase was constituted of the following elements: measure-ments, ”subjective” survey with closed questionnaires (only withadults) and observations (children’s typical comportments). We


also analyzed the correlation between the evaluation of acous-tic comfort before and after the modifications. We will demon-strate that, in this case, the decrease of reverberation time is notsystematically correlated with a decrease of the produced noiselevel and with the comfort degree of adults. These results will becorroborated by the analysis of children’s comportment in bothphases.


Schalltechnische Prognoseverfahren für FreizeitlärmJohannes HerholdSächsisches Landesamt für Umwelt und GeologieFreizeitanlagen und Freizeitaktivitäten erlangen in unserer Zeiteine immer größere Verbreitung. Ihre Nutzung ist häu-fig mit Geräuschemissionen verbunden und kann zu nach-barschaftlichen Konflikten führen. Zuverlässige schalltechnis-che Prognosen sind für die Planung und Genehmigung er-forderlich. In der Praxis sind jedoch gegenwärtig für zahlre-iche vorkommende Arten von Freizeitanlagen bzw. Freizeitak-tivitäten aussagefähige Daten über Emissionskenngrößen sowieBerechnungshilfen für die schalltechnische Prognose nur un-zureichend verfügbar. Berichtet wird über die Konzeption einesbausteinartig aufgebauten Systems. Ziel war es, eine zuver-lässige Bestimmung der Emissionskenngrößen auf der Grund-lage von einfach zu ermittelnden nichtakustischen Kenngrößender Anlage, z.B. bei Beschallungsanlagen die Flächengröße,die maximale Hörentfernung oder die elektrische Anschlus-sleistung der Beschallungsanlage, vorzunehmen und darausgeeignete Berechnungshilfen für die schalltechnische Prognoseabzuleiten. Hinweis: Vortrag nach Möglichkeit bitte in die gle-iche Gruppe und zeitlich unmittelbar vorher einordnen vor VortragCFADAGA2004/26 - Ederer, Hans-Jörg !

Tu. 8:30 Oberlin Soundscapes and community noise

The Multidimensional Evaluating of Soundscapes. AnOverviewBrigitte Schulte-FortkampInstitut für Technische Akustik , Technische Universität BerlinAmong the many potentials research ideas on soundscape someclearly have higher priorities. The question about the criteria (be-yond sound level) of a good soundscape or what is a sensitivesoundscape or what are the soundscape requirements of a re-sort area or a quiet area, which should be protected, are centralto the origin of the soundscape idea. In order to reduce noise-annoyance and improve soundscapes a planned echeloning ofthe eco-tax would be helpful. Other classical acoustics questions


such as the role of background noise, audibility, intrusivenessunder critical conditions, and under condition of mixed sourcesand time pattern should be asked differently than hitherto put todeepen insight and understanding. Both central questions shouldbe pursued only in the context of psychscape and enviroscapepreferably studied in different areas with a sufficiently large sam-ple of typical urban and rural layouts, lifestyles, and patterns ofland use


How to validate the urban soundscape?Catherine SemidorEAPBx -GRECOThe urban planners and others town designers need informationto improve the acoustic comfort of the cities. Among them arethe components of the urban sound environment. Its analysisfrom the standard data (measurements of the Equivalent SoundLevel with an omnidirectional microphone on one spot during adetermined period from a few seconds to a week or more) doesn’tallow to describe correctly the urban soundscape. It’s why wepropose a method based on the recordings with a ’dummy’ headand a DAT recorder of soundwalks through varied urban forms. Ina previous paper [Semidor C., PLEA 2003] we had shown how itallows to distinguish the soundscape of a ’car free’ Sunday fromthe soundscape of a Sunday with cars. We have applied thismethod to evaluate the soundscapes of different towns in Europeand we present here the results of these surveys.


How Different Sources Fill the Soudscape : a Perceptive andAcoustical ApproachBoris Defreville, Catherine Lavandier, Marc LanirayLASA et Université de Cergy-PontoiseIn order to assess urban soundscape, new indicators are devel-oped. These indicators should characterize the perception ofsound sources in urban environment : vehicles, human voicesand bird’s sings. Within the framework of this article, only in-dicators built on identification of the vehicles are presented. 5minutes of an uninterrupted sound stimulus, recorded in urbanenvironment, is presented to 20 listeners. A the end of the listen-ing, the subject is invited to evaluate 3 aspects of source percep-tion on a scale from 1 to 10. First, the ”pregnancy” of a soundsource is assessed as the importance which it takes in its en-vironment. Secondly, the ”presence” and at last, the ”proximity”of the source. A second auditive test is also proposed. 20 lis-teners hear the same 5 minutes sequence, cut into a serie of


20 stimuli of fifteen seconds each. After each 15 seconds se-quence, the listener is invited to note the 3 same appreciationspre-cited. At the same time, the search for data measuring thelikeness and the level of the sound sources is developed. Thelikeness measure, built from the spectral and temporal charac-teristics of a standard vehicle in a urban displacement, is storedin real time. A gauge adapted to each type of source is usedas a filter to store also in real time a temporal evolution of eachsource. Based on those curves, new relevant indicators are stud-ied to optimize their correlations with the perceptive ”pregnancy”,”presence” and ”proximity” evaluation of each type of source.


Cognitive approach of soundscapeDanièle Duboisc/o Laboratoire d’Acoustique MusicaleWe will present some results from a new method of explorationof the cognitive properties of soundscapes elaborated in our lab-oratory. From free categorization tasks associated to linguisticdiscourse analysis of real life experience of urban soundscapes,the results suggest that acoustic stimuli can be processed ei-ther as part of a meaningful event (i.e as NOISE) or, in a moreanalytic manner, along physical parameters (as SOUND), whenthe identification of the source fails. Language can be consid-ered as allowing an access to the diversity of cognitive concep-tualizations for acoustic phenomena : sounds and noises, bothpresent in soundscape, depending on the orientation of the cog-nitive processes and the activities we are involved in (a s pedes-trian vs driver, as worker or tourist..), on the knowledge and inter-est we have about these phenomena (mucisians, acousticians,3novices2), but also on the constraints from the recording andrestitution devices. Finally, we would like to point out that this di-versity of cognitive representations entails methodological conse-quences on sound restitution in experimental settings, and sug-gests the challenge of a 3reverse2 paradigm for studying sound-scapes, shifting from psychophysics to semiophysics.


The Importance of Grounded Theory with Respect to Sound-scape EvaluationAndre Fiebig, Brigitte Schulte-FortkampInstitut für Technische Akustik , Technische Universität BerlinThe perception of sound for human beings is a really complexphenomenon. For example acoustical, psychoacoustical, vi-sual parameters influence the sound perception in a confusingway. Especially in urban environments almost every sound is


unwanted and would be interpreted as annoyance. This studyaims at clarifying and improving the comprehension between as-sessment, response and attitude of inhabitants in urban environ-ments regarding their urban soundscapes. Narrative and issue-centered interviews were carried out to identify common percep-tive patterns in the process of judging urban soundscapes. Atthe same time acoustic measurements were conducted. Thiswork employs the methodology of qualitative-interpretative re-search since perception is constantly embedded in social con-texts. Therefore the analytical basis of the interpretation shouldbe the ?Grounded Theory? approach, a general methodologyof qualitative social analysis (developed by Anselm Strauss andBarney Glaser). It is expected to descry fresh relations betweengrounded categories which improve previous perception modelsand add further aspects to theories of multidimensional percep-tion.


Physical and perceptual point of view on soundscapes:comparing physics, perception, and analysisVincent Gibiat, Abril PadillaLaboratoire d’Acoustique Métrologie et Instrumentation, Univer-sité Paul SabatierPropagating sound waves implicates different analysis levels:the perceptual governs our sensations, the physical explains theacoustic source emission, and linked the geometrical and surfaceacoustical characteristics describe and bound the propagatingmedium. These three points have then to be represented throughsophisticated signal and perceptual analysis methods. The asso-ciation of a composer using natural recorded sounds as a musicalmaterial and a physicist working with sound waves in their wholecomplexity, amplitude and phase included, has been our startingpoint. Eliminating the physical aspect of the source, we concen-trated our work on the two other points. We recorded sound-scapes, produced in parisian underground (Metro) and ExpressRegional Network (RER). The recordings have then be describedwith the words of perceptual musical language when unusualphase spectrograms have been performed in conjunction withamplitude spectrograms or sound level representations. Thesehave been realised through classical Discrete Fourier Transformor Differential Spectral Analysis. We will present the comparisonof our diverging and converging analysis and give hints to explainwhy they diverge or converge. More important we will show thatperceptual effects as acoustical emergence of low amplitude sig-nals cannot be detected on signal analysis without the phase ofthe spectrograms.



Improving soundscapes through the Eco-TaxCay HehnerInstitut für Technische Akustik , Technische Universität BerlinIn order to tackle unbearable or even barely bearable noise an-noyance and work for an improvement of the quality of urban lifethrough noise reduction and ’indigenous’ soundscape improve-ment it has to be borne in mind that the ecological system oftaxation according to Henry George does not amount to ’yet an-other tax’ on top of the uncountable taxes already in place in mostcountries to interfere with the worldwide badly needed upswingof the business cycle. The Georgist tax of natural resources andkindred factors of production is not an accretion of taxes, but overa reasonable period of years or decades the replacement of othermajor taxes. If the producer and the laborer are taxed all the moreso in relation to their working more and being more productive atax system that does not punish the economic subject for morework and a higher production output with ever higher taxes, butrewards them with tax breaks, is apt to boost the economy over-all. And as all natural resources including air and any kind ofsound space are by definition preliminaries of any economic ac-tivity and as they are hence by definition communal from the fullfinancial responsibility of the community should derive. This pre-sentation will discuss various economic aspects of Georgist fiscalpolicy condusive to the furthering of an improved environmen-tal balance and a sound protection from excessive noise annoy-ance. These will come under the headers of: cost-benefit, price-earnings, illness-health, noise outsourcing-social acceptance.


Sound topologies as a spatial description of the sound-scape: The qualitative sound map of Rossio square in Lis-bonMohammed Boubezari, José Luis Bento CoelhoCAPS-ISTIn the qualitative approaches of the acoustical environment, thepsychoacoustics criteria of quality focus on the signal, and thesubjective criteria, usually describe the way in which a commu-nity perceives a noise. It misses an intermediate criterion thatallows us to describe the sounds in a soundscape before evento apply a socio-cultural or aesthetic judgement on it. The qual-itative cartography should thus distinctly report the sounds thatmake a (urban) sound environment intelligible with the same ratiothat they are perceived in situ. With this intention, the hypothe-sis of sound topologies obtained by a semantic filtering of a local


sound environment was tested. Sound topology is the spatial dis-tribution of a sound distinguished from its background. Semanticfiltering was obtained by using a ’subject’ in the protocol of theacoustic analysis of a locally recorded data, and by using thecocktail effect and the masking effect. The method was appliedto a part of the Rossio square in Lisbon, a major square in thiscity. A qualitative sound map was obtained that distinguishes thesound sources of the soundscape of the place. The reading ofthe soundscape is easier and faster. We believe that this type ofmap can target with more precision the intervention on the urbansound environment, which is to regulate a problem of annoyance,or management and recombining of the soundscape or control ofits evolution in the long term. The paper describes the methodand the first results.


Perception of Sound Quality of City Streets: Comparison ofGerman and Swedish SamplesGert Notbohm, Claudia Gärtner, Daniel Vjästfäll, SieglindeSchwarzeInstitut für Arbeitsmedizin und Sozialmedizin, Universität-sklinikum DüsseldorfThe SVEN project (Sound Quality of Vehicle Exterior Noise)funded by the EC aimed at describing the sound quality of ve-hicle exterior noise. In three laboratory experiments in Germanyand Sweden, factors influencing the subjects’ responses to traf-fic noise were studied. The same set of sound recordings fromcity streets in Paris was used for assessing the subjective evalu-ations of the subjects. The sounds were presented pair-wise withthe sounds of a pair resembling each other except one specificfeature such as type of building or traffic control. The 3 experi-ments were different with regard to cultural background (Swedishvs. German samples), but also in the variation of the sound pres-sure level of the stimuli. One tool for the assessment of the sub-jective evaluation of the sounds was an adjective list consistingof 27 items which had been developed as a questionnaire suitedgenerally to assess the perception of soundscapes. The data ofthe 3 samples were analyzed by Principal Component Analysis(PCA) separately and also as a joint data pool of 106 subjects.With minor differences, the PCAs show that 4 factors are most im-portant in the evaluation of urban traffic situations which can beunderstood as ”annoyance and danger”, ”time variation”, ”impactof non-traffic or single sounds”, and ”spatiality”. Index variableswere created by averaging over all items belonging to a factor.


The means for each component show interesting differences be-tween the 3 samples in the the perception of the traffic noiseswhich ask for interpretation.


The Importance of Sound Pressure Level in the Assessmentof Sound QualityClaudia Gärtner, Gert Notbohm, Sieglinde SchwarzeInstitut für Arbeitsmedizin und Sozialmedizin, Universität-sklinikum DüsseldorfThe joint research project SVEN (Sound quality of Vehicle Exte-rior Noise) funded by the European Union aims at investigatingthe possibilities of applying the methodological approach of as-sessing and optimising sound quality to vehicle exterior noise.In this context a laboratory experiment was carried out in whichsubjects were exposed to vehicle pass-by noises of two differ-ent middle-class cars (petrol or diesel engine) under the driv-ing conditions 70 km/h, 3rd gear, constant speed. Differentsound pressure levels were applied: Subjects listened to soundswith the original sound level of about 73 dBA and to the samesounds adjusted to a Leq of 83 dBA. In order to assess theindividual’s psycho-physiological reaction to the different pass-by noises, physiological measurements were taken continuouslyduring noise exposure. Additionally subjects had to evaluate thesounds subjectively by means of questionnaires. Results indicatethat under both sound pressure levels the sound of the car withthe petrol engine was evaluated more positively than the dieselcar. With regard to sound level, both cars were judged morefavourably when presented in the original sound level than com-pared to the higher adjusted one. For both cars, physiologicalreactions proved to be much stronger with the adjusted than withthe original sound level. However, there was a clear stronger re-action to the sound of the diesel car in both cases. Thus, thevalidity of the measures used is reinforced, but a sufficiently highsound pressure level is necessary to elicit meaningful differencesin physiological responses.


Airport Noise Assessment-Simplicity and truth will helpPaul SchomerSchomer and AssociatesCurrently, in the USA, we use DNL in decibels to assess noiseproducers such as airports and the EU is going in a similar direc-tion. We talk about SEL in decibels, maximum levels in decibelsand DNL in decibels?all physically different but all called decibels.Further, we talk about the Day-night Average Sound Level when


in is NOT an average. And then, as if this unintelligible technicaljargon is not enough, we sometimes outright lie in our assump-tions or statements. Then we wonder why the public is confused,upset and agitated. This paper offers a means to reduce the con-fusion generated by current assessment procedures as well asseveral up-to-date examples of the lies to the public that have noplace in noise assessments.


The Temporal Structure of the Urban SoundscapeDick Botteldooren, Bert De Coensel, Tom De MuerAcoustics Group, Department of Information Technology, GhentUniversityNoise annoyance and sleep disturbance are often used to assessthe quality of the urban sound environment. Recently a moreholistic approach including positive and negative aspects as wellas other than the residential function of the urban environmenthas gained renewed interest. The label ’urban soundscape’ isoften used to refer to this approach. Research towards quantifi-cation of the acoustical descriptors of the urban soundscape ishowever still in an early stage. Loudness and sound quality mea-sures have been suggested. The longer time scale has attractedmuch less attention. This paper draws on the analogy to musicto propose an indicator for studying the temporal structure of theurban soundscape. Sound level dynamic as measured by the dif-ference between event levels and background noise give a firstindication. The sequence and grouping of acoustic events willbe shown to add substantial information to the assessment. It isproposed to investigate this temporal structure by analyzing thespectrum of loudness fluctuations over a several minute period.It is known that this spectrum shows a typical 1/f structure formost musical genres. This gives us a hint for interpretation. Themain focus is on the temporal structure generated by road trafficand road traffic flow management. The link to underlying self-organized criticality, a quite common feature is natural systemsthat generates 1/f-like noise, is drawn.


Hearing-adequate Description of a Soundscape Based onStandardized Measurement ProceduresKlaus GenuitHEAD acoustics GmbHRegarding the soundscape the following approach is needed: theoverall effects of noises need to be observed in the context ofthe sensitivities of the human beings living in that said sound-scape. An important task herein consists in the description of the


sound events situated within the soundscape according to the re-quirements of its measurement technology. As it is well knownthe diminishing of the quality of life through the acoustical am-bience may not be registered alone by way of the A-weightedsound pressure level. With regards to the complex signal pro-cessing within human hearing at least equally complex proce-dures of analysis are required such as psychoacoustics param-eter like loudness, sharpness, roughness etc. At this point it be-comes an issue that, except for the loudness of stationary noiseno generally accepted calculation procedures have been speci-fied by standard. Until now no other measurement quantities inorder to describe noise annoyance in addition to the existing A-weighted sound pressure level can be requested by governmentregulations. On the other hand it is possible to deduce parame-ters based on known, standardized procedures of measurement, which approach the given psychoacoustic quantities more read-ily and thus allows a greater quality of assertion with regardsto noise annoyance than the mere regarding of the A-weightedsound pressure level or of the energy-equivalent sound pressurelevel respectively. The use of third-octave filters as well as theuse of sound pressure level meters that feature variable integra-tion times with constants far below 125 ms enable the user toapproximate several psychoacoustic parameters.


Audio-Visual Coupling in Human PerceptionMichael HaverkampFord Werke AG KölnRecent research shows that inter-modal properties of the hu-man perceptional system have to be included into an integraldescription of soundscapes. During the last 15 years, severalapproaches try to involve various aspects of inter-modal couplinginto investigations of sound perception. Most approaches, how-ever, focus on specific phenomena and interpret them from a par-ticular point of view. While different disciplines are involved, eachwith peculiar methodologies, there is lack of a total description,including all. This presentation introduces a model of variouslevels of audio-visual interaction suitable to classify all kinds ofcoupling. The main strategies of the perceptional system are de-scribed and principle rules of inter-modal coupling are discussed.This model provides an important approach for setting up experi-mental conditions as well as description of field conditions, princi-ples of visualisation of sound measurement results and proposalsfor a multi-modal product design.



Annoyance due to industrial noise: perceptual assessmentof legislation standardStéphanie Viollon, Catherine Marquis-Favre, Clément BaumannEDF R&DIn France, the legislation standard for characterizing annoyancedue to industrial noise is the ”sound emergence”, measured asthe difference between the A-weighted equivalent sound pres-sure level of the ambient noise (installation on) and the A-weighted equivalent sound pressure level of the residual back-ground noise (installation off). Besides in some conditions ofnoise exposure, this criterion seems to be inadequate to assessnoise annoyance as it is actually perceived by the surroundingpopulation and is worth examining in a more-in-depth way. In-deed, EDF, concerned with developing a global policy of sus-tainable development, is interested in a perceptual assessmentof noise annoyance due to its installations. The aim of our re-search work is to examine the legislation standard ”sound emer-gence”, through a perceptive test. Subjects have to evaluatethe perceived annoyance when listening to industrial sources,mixed with background noises according to an environmental ap-proach. Our experiment involved: 3 background noises (natu-ral sound environment, quiet environment and road traffic noise),mixed with 4 industrial sources noises (cooling tower, power plantturbine, transformer with fans and wind turbine), controlling thesound emergence (+3dB and +5dB). Results are presented andthe experimental parameters are discussed.


Noise abatement in Switzerland: present projects and per-spectivesHans Boegli, Irène Schlachter, Marc Schaffner, Jean-DanielLiengme, Fredy FischerBundesamt für Umwelt, Wald und Landschaft (BUWAL)Noise abatement has a long history in Switzerland. The recog-nition of noise as a public health problem led to a parliamen-tary report in the sixties and finally to a noise policy which waslaid down in the Environmental Protection Law (1983) and in theNoise abatement ordinance (1986). The policy contains plans tostudy dose-effect relationships, to introduce limiting values andto apply measures, focusing on reducing noise mainly at thesource. Costs are handled according to the polluter-pays prin-ciple and prevention measures to avoid future noise problemsas well as improvement measures for existing noisy installation


have been stipulated. A critical review of 15 years of noise abate-ment published in 2002 proposed further actions to improve thestrategy. In particular, the report recommended a better moni-toring of noise abatement, concerning noise exposure and im-provement projects. It also suggested a closer collaboration withinternational noise policies, especially with view to ongoing EU-activities. The report concluded that supplementary measureswere needed in order to effectively protect the population fromhazardous or undesirable effects of noise. Some of the proposedmeasures are presently being implemented. It concerns the in-troduction of a national monitoring system of noise exposure, astricter control over the slowly-progressing improvement projectsas well as tighter regulations to monitor noisy installation. Furtherprojects deal with the quantification of noise effects on health bymeans of the DALY-principle (disability adjusted life years) and itsmonetisation in order to cover the external costs of noise.


Soundfield reproduction: the limits of the physical approachJean-Dominique Polack, Michèle Castellengo, Valérie Maffiolo,Corsin Vogel, Catherine Guastavinoc/o Laboratoire d’Acoustique MusicaleSoundfield reproduction is usually based on the physical repro-duction of the sound heard at the ears of the listener, preferablyby means of HRTF. However, most listeners have experiencedthat this reproduction has little common with real life. We pro-pose a methodological shift in soundfield reproduction, based onGibson?s concept of ecological validity. Instead of accurately re-producing the physical signals impinging on the ears of the lis-teners, we propose to focus on the meaning of the signals heardby the listeners. Three examples of the interaction of meaningwith signals are given to illustrate the limits of the physical ap-proach: the effect of temporal organisation on loudness; the influ-ence of perception threshold on the meaning of warning signals;and background noise perception thresholds at low frequencies.The poster focuses on the different recording and reproductiontechniques adapted to these different situations. This poster isan illustration of Danièle Dubois?s contribution to the session?Soundscape and communitynoise?.



Approaches to classification of urban areas in relation totransport noise impactBarbara Lebiedowska, Michel MaurinTechnical University of Lodz, Department of Building Physics andBuilding MaterialsTransport noise and its distribution are conditioned not only byroad- and street-loads but also by the spatial organisation of aregion, and, in urban areas, also significantly by the spatial (geo-metric) form of the city. Our aim is to determine the relationshipbetween energy distribution and urban morphology, despite themultiplicity of factors influencing noise propagation in built-up ar-eas that render this issue difficult. These factors may be clas-sified in three groups: physical factors (source - propagation ofthe acoustic wave), geometric factors (geometry of an area to-gether with its buildings), and human factors (vulnerability to ex-cessive noise, differentiated perception). Due to the time neededfor in situ measurements, and, consequently, required financialresources, and because of a somewhat limited body of data pro-vided by them, direct study methods are necessarily substitutedwith increasingly more common computer simulations. Whilemeasurements are first of all a reflection of the actual situation,and their comparison is possible exclusively in the case of actual,existing urban structures, simulations make it possible to assessthe influence of individual elements defining the geometry of acity. Attempts at comparative analysis based on simulations andin situ studies have been made by a number of research cen-tres. In this presentation, primary attention is given to the studiesconducted at INRETS, using both in situ measurements and theresults of simulation techniques. A certain limited classificationof urban areas in relation to transport noise impact is proposedon their basis.


Unconventional method of the evaluation of acoustic com-fort of pedestrians in urban spaceBarbara Lebiedowska, Jacques Beaumont, Marek JablonskiTechnical University of Lodz, Department of Building Physics andBuilding MaterialsA number of indicators are used in room acoustics to define thequality of the reception of an acoustic signal and, consequently, toevaluate the acoustic quality of an enclosed space from the pointof view of the audience. It may thus be accepted that acoustic in-dicators applied in room acoustics, such as Reverberation Time(RT) or Early Decay Time (EDT), could also be employed for the


purposes of the acoustic evaluation of urban interiors, includingopen spaces. It would contribute to an improved assessment ofacoustic comfort of occupants of such a space, as, for instance,pedestrians travelling through city streets. A direct analysis ofthe acoustic climate of urbanised spaces, based on in situ mea-surements, both requires a great deal of effort and is highly ex-pensive. The measurement procedure may, however, be elim-inated in many cases, and the interpretative process, useful inseveral preliminary analyses, simplified. A simple analogy be-tween an enclosed space, limited by strict geometric dimensions,and an open space whose boundaries are arbitrary, was the un-derlying assumption in the analysis. Computer simulations ofsuch spaces were examined. The simulations relied on numericalcalculations performed in keeping with the European standardsbased on the Mithra program (software used in out-door acoustic)and the Odeon program (software used in room acoustic). Theanalysis of the results shows that the methodological approachadopted should be developed and future studies on the issue arecalled for.

Tu. 8:30 Arp 1 Measuring methods in building acoustics II

Sound Absorption of Microperforated Duct SystemsSteffen Hettler, Philip LeistnerFraunhofer Institut BauphysikIn recent years, the concept of microperforated sound absorbershas been successfully implemented in various applications, suchas transparent panel absorbers, microperforated foils or sus-pended ceilings. For the first time, interior design and roomacoustics were merged by using various benefits of microperfo-rated absorbers. In order to introduce the principle of microperfo-ration to further engineering areas, micro perforated ducts havebeen investigated as a visible element of the room. In this case,air flows through the microperforation. Hence, not only the venti-lation aspects have to be designed but also the sound absorptioneffects need to be taken into account. For this purpose, the the-ory of a microperforated absorber was extended by the effectscaused by airflow through the microperforation. Experimental ev-idence is provided. The investigations show a high sound absorp-tion characteristic, which results in an attractive and flexible roomacoustic element that can be easily integrated into duct systems.



The Virtual Reality Acoustics Laboratory - SonicLabStefanie Litjens, Schew-Ram MehraLehrstuhl für Bauphysik der Universität Stuttgart und Fraunhofer-Institut für BauphysikAcoustic measuring technology and methods of measurementform substantial parts of student training in the fields of build-ing acoustics, room acoustics, noise and noise control. Due tolack of test rooms, time and money, mostly transparencies andslides are used to explain acoustic metrology. The virtual real-ity acoustics laboratory ’SonicLab’ was developed with the aimof providing a close-to-practice training option for students: using’SonicLab”, interactive measurement processes are made avail-able in the network. Up to now, it is possible to perform measure-ments in the following virtual-lab test chambers: wall and windowtest facility, floor and ceiling test facility, reverberation room. Inperforming virtual measurements, students can get familiar withtest chambers, measuring instruments and measurement proce-dures. Graphical views, animated images and instructional filmsallow to convey a close-to-reality impression of test facilities andmeasurement processes. In the lecture it will be demonstratedhow to select different test objects in the virtual test rooms andhow to compare the experimental results to analyses of furthermeasurements.


Building and Room Acoustics Measurements with Sine-Sweep TechniqueOle-Herman Bjor, Igor NikolicNorsonic ASNew measurement methods based on digital signal processingbring a number of advantages compared to well-established clas-sical methods for the measurements in building and room acous-tics, such as extended signal-to-noise ratio (SNR) and high dis-tortion immunity. Importance of these techniques is confirmedby the fact that the International Organization for Standardiza-tion (ISO) is working on a standard for applications in buildingacoustics. The paper presents a real-time implementation of thismeasurement method, based on excitation with a logarithmic si-nusoidal sweep and focuses on its practical use and benefits.Comparisons with methods based on maximum-length sequencetechniques are also given.


Tu. 9:30 Arp 1 Rating methods in building acoustics

Assessment of the Impact Sound Insulation by Light weightFloors and Floor CoveringsJudith Lang—A method to assess the reduction of impact sound level by floorcoverings on massive floors by a single number, based on stan-dardised measurements is laid down since many years in ISO717-2. A similar procedure for floor coverings on light weightfloors however has not been defined until now. Only during thelast years ISO 140-11 has been drafted describing the method ofmeasuring the reduction of impact sound level by floor coveringson light weight floors (type of typical bare floor and excitation).With that the question about a single number definition based onthe results of these measurements arose. To gather informationon the impact sound level of light weight (wooden) floors with andwithout floor coverings and useful types of reference curves forthe lightweight floors a series of measurements has been car-ried out on the reference floor Nr.1 (typical for European woodenfloors) with excitation of the floor by the standard tapping ma-chine, the modified tapping machine and the ”heavy soft impactsource” (rubber ball), which are described in ISO/DIS 140-11.Additionally measurements with walking persons with differenttypes of shoes were carried out on some floor coverings. Theresults were compared with respect to the single numbers for theimpact sound level of the floors. The single numbers for the re-duction of impact sound level for all tested floor coverings werecalculated with proposed reference curves for 2 types of woodenfloors and the suitability for their application was tested.


Psychoacoustic studies on the evaluation of impact soundof lightweight stairsAndreas Drechsler, Heinz-Martin FischerFachhochschule Stuttgart - Hochschule für TechnikImpact sound measurements of lightweight stairs often show alack of correspondence between the evaluation according to thestandards and the hearing impressions of the inhabitants. As aconsequence actual measuring and rating procedures seem tobe not suitable to avoid annoyance. To improve this situation andderive evaluation methods closer to the subjective impressions,some first psychoacoustical studies were made, in addition tophysical investigations already presented at earlier DAGA con-ferences. Different walking noises on lightweight stairs were in-vestigated to characterise them from a psychoacoustical point of


view. Also a listening test with 21 persons was conducted. Fur-thermore psychoacoustic quantities of different artificial impactsound sources and of human walking and jumping were mea-sured and compared. The intention was to find the most appro-priate impact sound source to represent impact sound by realwalkers.


A First Step towards Auralisation of Impact NoiseRainer ThadenInstitute of Technical AcousticsFor a subjective evaluation of the annoyance of impact sound,listening tests have to be performed. It is very time consuming tocollect material for the tests as the noise has to be recorded inreal buildings. Therefore an auralisation of the receiving roomsignal based on the typically available data of a constructionwould be desirable. As a first step, an auralisation of the im-pact sound insulation based on the normalised impact soundlevel is done. The force time signal of the source (walker, balletc.) is measured and the dynamic interaction between sourceand structure is neglected. Accordingly, only floors with a highimpedance (heavy-weight constructions) can be considered. Asimple algorithm for synthesizing the force-time signal e.g. of awalking person by single footsteps is used to generate the inputsignal for the model. The receiving room is modelled in the sameway as in a model for airborne sound insulation which was de-veloped some years ago. In the presentation, the model and firstresults will be shown and ilustrated in audio examples.


Walking Noise: Physics and PerceptionEnnes SarradjGesellschaft fuer Akustikforschung Dresden m.b.H.Hard floors such as laminate became increasingly popular in thelast years. As a consequence, the annoyance by the noise fromwalking over such floors became a problem. This problem wasaddressed by various efforts to manufacture less annoying floor-ings. In order to assess the quality of each solution, a number ofdifferent rating procedures were developed. These proceduresoccur to lead not to consistent results. One main reason for thatis a lack of knowledge regarding the physical mechanism of walk-ing noise production. Another reason is that there is not muchknown about the perception of walking noise. The presentationaddresses several open questions both from a physical and per-ceptional view and explains some necessary prerequisites for arating method. Preliminary results of calculations for the sound


generation by the impact on the flooring are shown and importantinfluence factors will be listed.


Evaluation of walking noise on floorsHartmut Schröder, Bettina RichterFraunhofer Institut BauphysikApart from impact noise in adjacent rooms, walking noise in thesource room - also referred to as drum noise - is of increasing in-terest. Drum noise is not a subject of authority regulations in Ger-many. This situation offers space for newer measurement tech-niques und evaluation procedures away from the well-establishedsingle number values. Psychoacoustic findings could be consid-ered more appropriate and the sound of drum noise itself couldbe investigated. A measuring method for in-room impact noise byfloor coverings was developed in France (NF S 31-074), whichis based on laboratory measurements using the standard tap-ping machine. Several institutes in Scandinavia and Germanycreated their own measurement procedures using also differenttypes of excitation and more sophisticated measurement tech-niques. About one year ago a European standardisation group(CEN/TC126/WG1/AHG7) was established under active partici-pation of the European Producers of Laminate Flooring (EPLF).The aim of this group is to agree upon a unique test method tocharacterize walking noise of floor coverings. One of the param-eters in focus is the loudness according to Zwicker. The cur-rent state of the discussion will be reported. Further more, somemeasurements from persons walking on different floors will bepresented. The hearing impression is then compared to the de-termined rating parameters.

Tu. 15:30 Arp 1 Building acoustics I

A review of partition’s transparency analytical calculationmethodsAntoine Pellicier, Nicolas TrompetteINRSThere are several methods used for the calculation of partition’stransparency. This work deals with direct analytical methods asopposed to deterministic modal methods, more accurate but alsoless rapid. Various ways of modelling partitions are tested here:at first, well-known classical methods are used to model trans-mission of sound through an unbounded single or double leafpartition in pure bending. For double leaf partitions, absorptionin-between panels is added using Delaney & Bazley ’s theory (i.e.limited to fibrous absorbent material). Then, to take into accountthe shear, Munjal’s model based on the calculation of transfer


matrices for each component of the partition and their assembly,has been implemented. It also allows the introduction of porousmaterial inside panels by means of the Biot & Allard’s theory. Atlast, a spatial windowing on the infinite panel transmitted wave,stemming from Villot & Guigou’s work, has been added. It al-lows the extension of all models to finite panels. At each step, acomparison with measured data found in literature is done.


Sound Reduction Index and Mode Shapes of Cavity WallsJochen SeidelXella T&M BautechnikAt the last conference DAGA’03 laboratory measurement resultsof cavity walls were presented by the author. Differences of morethan 10 dB in Sound Reduction Index were observed with wallseven though they had the same mass per area and the samewidth of the cavity. It was found that differences in the modal fre-quencies between the two leafs of the wall lead to higher SoundReduction Indices. This year further results will be presented.We have made more measurements not only in the transmissionsuite but also at construction sites. Again, we found that differ-ent modal frequencies of the opposite wall leaves gave a highersound reduction. Moreover, we had a closer look at the modeshapes themselves. Movies of the mode shapes in motion willbe shown. The value of modal testing methods as a tool in theacoustics of cavity walls will be discussed.


Zweischalige Haustrennwände mit vollständiger und unvoll-ständiger TrennungJürgen Maack, Elmar SälzerITA Ingenieurgesellschaft für Technische Akustik mbHBei Reihenhäusern mit ’Weißer Wanne’ im UG oder bei keller-losen Reihenhäusern mit durchgehender Bodenplatte liegt eineunvollständige Trennung vor. Für derartige Konstruktionen wur-den die Schnellepegeldifferenzen an den Stoßstellen sowiedie Schalldämmung zwischen den Räumen an ausgeführtenBauten messtechnisch untersucht. Auf Grundlage der ermitteltenSchnellepegeldifferenzen wird es möglich, die Schalldämmung inAnlehnung an DIN EN 12354 zu berechnen.



Investigation of the Sound Transmission through Double-leaf Separating Walls with respect to Incomplete SeparationJochen Scheck, Heinz-Martin Fischer, Martin SchneiderFachhochschule Stuttgart - Hochschule für TechnikThe separating walls between attached row and twin houses usu-ally are of heavyweight cavity construction. For stability reasonsthe two leaves of the wall in most cases are structurally linked,particularly through the ground plate. This bridging increases thesound transmission of the cavity wall and also the flanking trans-mission. However, the international standard ISO 12354-1 offersno prediction methods for such cases. In order to investigate thedirect and flanking transmission of heavyweight cavity walls, fieldmeasurements have been carried out at various building situa-tions. The presentation contains the latest results of the survey.


Influence of Flanking Transmission on Impact Sound Insula-tion in solid Multi-DwellingsMartin Schneider, Katrin Kohler, Heinz-Martin FischerFachhochschule Stuttgart - Hochschule für TechnikIn solid multi-dwellings the airborne sound insulation between ad-jacent dwellings is often reduced by transmission of lightweightsolid flanking walls. The transmission of these walls is not clearlytaken into consideration, predicting the impact sound insulationaccording to the German standard DIN 4109, Beiblatt 1 (1989).Author: However, the calculation procedure according to the Eu-ropean standard DIN EN 12354-2 Simplified Model considers theflanking transmission globally using the averaged mass per unitarea of the flanking walls in the receiving room. The DetailedModel of DIN EN 12354-2 considers the flanking transmissioncalculating the sum of the transmitted energy via the separatingand the flanking elements. Within a research project at the Fach-hochschule Stuttgart- Hochschule für Technik the predictions ofthe impact sound insulation using Simplified and Detailed Modelof EN 12354-2 will be compared. The calculated weighted nor-malized impact sound pressure level will be compared with mea-sured in-situ data. Further investigations will be predicting the in-fluence of the flanking transmission on impact sound insulation.Therefore structure borne sound measurements were carried outto determine the individual flanking transmission on each path.Using calculated and measured data the influence of lightweightsolid flanking walls on impact sound insulation will be discussed.



Radiation Factor Correction when calculating FlankingTransmissionHeinrich MetzenDataKustik GmbHThe calculation scheme in EN 12354-1 and -2 calculates theflanking transmission index Rij from the sound reduction inde-ces Ri and Rj of the elements in each transmission path. Thesesound reduction indeces result mostly from tests performed intransmission suites according to ISO 140. This procedure leadsto an overestimation of the flanking transmission caused by thedifference in the radiation factor for forced and free bendingwaves. When predicting sound insulation it is would be usefulto apply a correction to account for the different radiation effi-ciency below the critical frequency. Approaches to consider thiseffect are discussed and compared with measured data. Datafrom fields measurements are presented to judge whether theproposed correction increases the accuray of the predictions indifferent building situations.


Flanking sound reduction of suspended ceilingsBettina Richter, Hartmut Schröder, Philip LeistnerFraunhofer Institut BauphysikIn 2003 a series of measurements on suspended ceilings madefrom closed gypsum boards was carried out at the Fraunhofer-Institute of Building Physics (IBP). The reason for these investiga-tions was, that construction examples given in the German stan-dard DIN 4109 are based on very old measurements. Since thattime, building materials have been modified and some acousti-cally important features as the mass per unit area and the thick-ness of currently available products have changed. Furthermore,the corresponding test code DIN EN 20140-9 has gone throughsubstantial changes. The focus of the measurements was puton the construction examples given in table 26 of supplement 1to DIN 4109. The measurement program is presented in detailand different parameters, which influence the flanking sound re-duction are explained when looking at the results. The singlenumber values are compared to the existing table 26 and somehistoric measurements. As DIN 4109 is currently revised, someproposals are made for new design values of the flanking soundreduction of suspended ceilings.



Modern Masonry Walls - Plaster versus Open JointsRalph HaberkernFraunhofer Institut BauphysikOpen vertical joints inside plastered masonry walls are a well-established way to reduce the expenditure of human labour inconstruction work. Due to the same reason, modern bricks andclassical bricks fundamentally differ in their proportions: the wallthickness diminishes and the in-plane dimensions increase. Inparticular, the increase in height has to be mentioned. Due tocost effectiveness, both techniques are often combined. As longas the open vertical joints are small compared to the length of thebrick, the vertical stiffness of a wall - the vertical Young’s modulus- is hardly affected by thin open joints. Hence, the static loadcapacity is about the same. However, this does not hold for othereffective elastic properties of the wall, e.g. the in-plane shearmodulus. By means of a suitable homogenisation software, thedependence of the effective elastic properties of a plastered wallof simple bricks on the in-wall proportions, the wall thickness,gap size and plaster layers has been investigated for sand-limestone. The method has been compared to experimental data.It is found that for thin walls the plaster plays an important rolein sustaining the shear stiffness of walls. Sufficiently thick andarmored, the plaster transfers most of the shear loads across theopen gaps, especially for thin walls. Hence, the plaster and itsconnection to the wall plays a important - but rarely perceived -role in concurrent masonry.


In situ Characterisation of materials using parametric sonarManell Zakharia, Manell HibralEcole navale, IRENAVParametric sonar techniques have been intensively used in un-derwater acoustics since the early sixties for bottom observa-tion: both qualitative (geometrical structure of the sub-bottom)and quantitative (impedance estimation) measurements. Nev-ertheless, the application to airborne acoustics was envisagedmore recently (in the eighties). The principle consists in trans-mitting two primary high frequency signals at high power in orderto generate a low frequency directive source. An airborne sonarsystem has been developed in order to characterise acousticsmaterial in situ. As characterizing insulation panels in a factory(in the presence of noise and multipaths) is similar to the charac-terisation of sea sediment in situ, similar sonar approaches havebeen used. In particular, the parametric array principle has been


used to generate low frequency chirps and gain in signal to noiseby pulse compression. Several results will be presented usingan airborne parametric sonar for the characterisation of acous-tic foam (insulation panels) in both transmission and reflectionmodes. The data obtained with this equipment will be comparedto the results obtained with conventional methods (in a reverber-ation room) for a wide band of frequency in a noisy room of a fewsquare metres. The final objective is the in situ characterizationof installed materials in order to validate the installation, to detectdefective panels and/or to study the aging effect. This work wassupported by the European Commission in the framework of theISCAP project (G6RD-CT-2000-00040).


Acoustics Learning Programmes - Precision Versus Inten-tionHolger Röseler, Schew-Ram MehraLehrstuhl für Bauphysik der Universität Stuttgart und Fraunhofer-Institut für BauphysikIn the field of building physics, teaching acoustics presents a ma-jor constituent in the training of civil engineers and architects atGerman technical colleges and universities. Relating acousticphenomena using conventional teaching and learning methodsoften requires rather complex efforts when performed in presenceteaching. By applying computer-assisted learning programmes,illustrations and auralisations, these phenomena may be intro-duced to the students in quite an impressive way. In developingsuch learning units, the question as to the units’ precision and ac-curacy turns up constantly: Is it really necessary to consider eachand every detail when calculating acoustic phenomena with alearning programme (running the risk of pushing some phenom-ena into the background) - or should the programme be ratherkept simple, in order to make the student familiar with the funda-mental phenomena? Within the framework of the project ’Multi-media Learning-Network Building Physics’, which was funded bythe German Federal Ministry for Education and Research and in-cluded the participation of another five German colleges and uni-versities, numerous building-physics learning programmes weredeveloped, also for the field of acoustics. In this context, theabove-mentioned question concerning the precision and the in-tention of such programmes was posed repeatedly. This issuewill be discussed in the lecture using examples from the acous-tic practice. The lecture will also include the presentation anddiscussion of learning programmes and illustrations and aurali-sations that have emerged from the project work.


Tu. 8:30 Arp 2 Temporal envelope processing in hearing

Neural coding of carrier- and envelope periodicity in the au-ditory brainstemLutz WiegrebeDept. Biologie II, Universität MünchenComplex periodic sounds evoke a pitch sensation when theirenvelope- or carrier period is in the range between about 0.7 and30 ms (fundamental frequency, f0, about 33 to 1400 Hz). Electro-physiological recordings in the auditory nerve of mammals haveshown that an autocorrelation of the temporal discharge patternsof auditory-nerve fibres provides a good physiological correlate ofthe pitch perceived by humans. But how is a computation akin toautocorrelation performed in the central auditory system? HereI show that neurons with intrinsic oscillations (chopper neurons)in the cochlear nucleus provide a selectivity for the f0 of periodicsounds. A chopper neuron with an intrinsic oscillation equal tof0 synchronises to f0 if it is stimulated by f0 or an integer multi-ple (a harmonic) of f0. These neurons behave like a template-matching device, only this template is neurally implemented inthe time domain, not in the frequency domain. Thus, this physio-logical model of pitch shows characteristics of both temporal andspectral functional models of pitch extraction. Chopper neurons,together with the neurons they project to in the inferior colliculus,provide a neural place code for pitch as it has been described inthe auditory cortex.


Analysis of reproducibility in auditory evoked responsesBoris Gourévitch, Régine Le Bouquin Jeannès, Gérard FauconLTSI - Université de Rennes 1The reproducibility of cortical responses to acoustic stim-uli is crucial in order to draw conclusions from stereo-electroencephalographic (SEEG) studies. The present researchfocuses on the repeated responses to amplitude-modulatednoises. A database composed of responses recorded from 20epileptic patients is used. Preliminary analyses show that neuralresponses display oscillating features for different auditory corti-cal areas, and that these oscillations occur at the stimulus’ mod-ulation frequency. Estimating parameters in these signals (am-plitude, phase, frequency...) depends on both mathematical esti-mator variance and biological recording variance. More detailedanalyses show that the variance observed when measuring am-plitude, phase or frequency of the oscillation for the repeatedrecordings depends only on the level of depth SEEG activity.The recording procedure was such that two different stimuli were


recorded in turn randomly. Additional analyses show that the os-cillation amplitude remains constant in the course of the record-ings: for 16 patients out of 20, more than 50% of leads showa constant amplitude (for 11 patients, the percentage reaches80%). For the remaining patients, some decreasing linear trendsare observed for 20% to 80% of leads. These results suggestthat the auditory system generates reproducible oscillation am-plitude, and that envelopeprocessing time (from the external earto the cortical areas) is identical for all recordings. This justifiesthe usual averaging of auditory responses to obtain AEPs.


The processing of complex envelopes in the normal-hearingand the hearing-impaired auditory systemJesko Verhey, Stephan Ewert, Torsten DauCarl von Ossietzky Universität OldenburgMany natural sounds including speech exhibit a complex tempo-ral envelope. Psychoacoustical and physiological studies showedthat the auditory system is sensitive to the envelope pattern. Re-cent modulation-detection experiments using complex envelopesindicate that the auditory envelope processing is nonlinear. How-ever, the nature of the nonlinearity is still unclear. In the presentstudy, psychoacoustical modulation masking data for normal-hearing and hearing-impaired subjects are presented, togetherwith model predictions testing different types of nonlinear pro-cessing. The model predictions and the similarity in the ex-perimental patterns obtained for normal-hearing and hearing-impaired subjects demonstrate that cochlear compression doesnot play a major role in the processing of amplitude modulation, incontrast to findings previously published by Moore et al. [Mooreet al., 1999, J. Acoust. Soc. Am., 106, 908-918]. A model for theprocessing of complex envelopes in normal-hearing and hearing-impaired subjects is proposed.


Perception of the envelope beat rate of inharmonic, complextemporal envelopesChristian Füllgrabe, Christian LorenziLaboratoire de Psychologie Expérimentale - UMR CNRS 8581,Université René Descartes Paris 5Listeners can detect slow, sinusoidal variations in the depth ofsinusoidally amplitude-modulated (SAM) stimuli. Here, the SAMstimulus of rate fm acts as a carrier (or ’1st-order’) SAM, and theslow variation in depth of rate fm’ - referred to as ’2nd-order’ SAM- corresponds to a beat in the temporal envelope (Lorenzi et al.,


2001). Recent studies have suggested that 2nd-order SAM de-tection is mediated by the detection of a modulation distortionproduct at fm’. This suggestion was tested by transposing tothe temporal-envelope domain the paradigm used by Schoutenet al. (1962) to study the perceived pitch of inharmonic SAMtones. In the present study, listeners were asked to estimate the2nd-order rate evoked by a 2nd-order SAM white noise using anadjustment procedure. The 2nd-order rate fm’ was fixed at 5 Hz.The 1st-order rate fm corresponded to 15, 20, 35, or 60 Hz (i.e.the 3rd, 4th, 7th, or 12th harmonic of fm’), or was shifted in fre-quency by df (ranging from -/+ 25-100 % of fm’) relative to thesefrequencies, making the complex envelope inharmonic. The dataindicate that the perceived 2nd-order rate is mainly shifted at thelowest 1st-order rates, contradicting the notion that listeners useonly a distortion product when perceiving 2nd-order SAM rate.However, the observed shifts were smaller than what would bepredicted if the perceived 2nd-order rate were entirely based onthe 1st-order envelope periodicity. The results are discussed inlight of the model developed by Ewert et al. (2002).


Are fine structure cues an important feature for temporalstreaming ?Nicolas GrimaultUMR CNRS 5020 ’Neurosciences et Systèmes Sensoriels’Alternating sequence of two A and B bursts of sound tends tobe perceptually organized in different auditory streams when in-troducing either a spectral or a temporal difference between Aand B. The spectral difference between A and B sounds canbe simply a frequency shift for pure tones or a spectral-pitchshift for complex sounds. In general, the channeling theory ofstreaming predicts that any salient difference between the exci-tation patterns evoked by A and B sounds would lead to a segre-gated percept. Some previous studies have however evidencedthat a sequence of sounds with similar spectral properties butwith different temporal properties can be heard as segregated.In particular, temporal envelope cues are probably responsiblefor the segregated percept when hearing a sequence of burstsof white noises that are amplitude-modulated at widely differentrates. All previous streaming experiments involved stimuli thathad frequency components bellow 5000 Hz. As a consequence,the individual contribution of temporal fine structure cues and en-velope cues could not be dissociated and remains largely un-determined. The current experiment is dedicated to test furtherthe relative importance of both envelope and fine structure cuesto segregate sequences of unresolved harmonic complex tones


with different fundamental frequencies. Two high- frequency re-gions above and bellow 5000 Hz and several phase relationshipsleading to several temporal peak factors have been used in asubjective streaming task.


Cross-Frequency Temporal Envelope Correlation for the Pro-cessing of Degraded Speech: Preliminary InvestigationsOlivier Crouzet, William Ainsworthacoustique, acquisition, interprétation (JE 2220) - Université deNantesIt is well known that long-term temporal envelope information iscrucial to the identification of speech in quiet. The present in-vestigation aims at considering its influence for the processingof auditory mixtures. The cross-frequency correlation of tempo-ral envelope modulation was computed on a subset of the ’TI-Digits’ database within various amplitude-modulation channels(0-4Hz, 4-8Hz, 8-16Hz, 16-32Hz, 32-64Hz) after passing themthrough an 8-channel FIR filterbank. It is shown that, whicheveramplitude-modulation channel is considered, the envelope ofspeech signals is highly correlated between spectral channels,especially when they are close to one another. In order to inves-tigate the likely influence of temporal modulation in the process-ing of degraded speech, a behavioral experiment is presentedin which participants had to identify digit sequences that werepreviously passed through a signal processing algorithm. Thisalgorithm is aimed at removing various levels of the temporal in-formation available in the speech signals while keeping their finespectral structure intact. Mixtures of these processed speechsignals with either steady-state or amplituded-modulated noisesignals were presented for identification. Interestingly enough,while the processing of speech signals was easier in modulatedthan in steady-state noise when long-term temporal informationwas available, the reverse occurred when temporal modulationswere highly filtered. Processing speech with few temporal enve-lope information led to better performance in steady-state than inamplitude-modulated noise. The implications of this observationfor the understanding of speech perception processes in adverseenvironments are discussed.



Temporal-envelope related processing in advanced digitalhearing aidsVolkmar Hamacher, Eghart Fischer, Henning PuderSiemens Audiological Engineering GroupNoise reduction, compression and classification algorithms havebecome standard features in advanced digital hearing aids. Inthis paper it will be illustrated that analysis and appropriate pro-cessing of the signal envelope play an important part in design-ing these algorithms. In the field of compression algorithms theappropriate speed of gain adaptation is still the subject of discus-sion. From a physiological point of view, compression algorithmsshould act as fast as possible to restore the loss of compressiondue to the damage of outer hair cells. Fast compression stronglyaffects the signal envelope. However, in listenings tests hearingimpaired subjects often prefer slow compression systems, whichdo not affect the signal envelope. This indicates that the appropri-ate ”transmission” of the signal envelope is a crucial point in com-pression algorithms. In respect of noise reduction algorithms,it will be shown that an early group of approaches exploits thespecific envelope properties of speech and noise to slowly adaptthe frequency response of the hearing aid to the noisy condi-tion. Moreover, it will be demonstrated that the processing ofstate-of-the-art procedures like spectral subtraction or Wiener fil-tering can be interpreted as the frequency-specific restaurationof the temporal envelope of the (undisturbed) speech in each fre-quency band. Some hearing aids already offer classification sys-tems which automatically enable the optimal hearing aid setting.It will be demonstrated that robust classification systems capa-ble of distinguishing between ”Speech”, ”Speech in Noise” and”Noise” situations can be developed mainly based on the analy-sis of the signal envelope.


Temporal envelope coding in the inferior colliculus. Evalua-tion of two computational models of octopus cellsAlexandre Guérin, Gérard Faucon, Régine Le Bouquin JeannèsLTSI - Université de Rennes 1Amplitude modulation (AM) is a common feature of sounds likespeech, and plays an important role in intelligibility. This paperpresents two computational models of octopus cells of the in-ferior colliculus (IC), known to be involved in the temporal cod-ing of AM. These cells, characterized by onset responses, arerespectively based on i) the McGregor point neuron equations,


ii) ion concentration gradient and Nernst equation. The evalua-tion is conducted using a global auditory model of AM encoding,simulating processes taking place from the external ear to theIC. The model includes a gammatone filterbank (cochlear stage),followed by a model of inner hair cells (transduction stage) anda discharge generator (auditory nerve stage: AN). The resultingAN discharges correspond to the inputs of a simplified cochlearnucleus, modeled as a bank of stellate cells (SC) with similarsame Best Modulation Frequencies (BMFs). Each SC neuron isimplemented using modified Hodgkin-Huxley equations, with pa-rameters tuned to produce chopper responses with BMFs rang-ing from 60 to 200 Hz. The neuron axons project to the IC modelwhere octopus cell models enhance the synchronization to thestimulus AM by detecting the coincident activity in the SC in-puts. Simulations show that different types of temporal modu-lation transfer function (t-MTF) can be obtained with a limited setof parameters and identical inputs. Measures of synchronizationindex show that the model based on Nernst equation is able tosynchronize over a wide range of modulation frequencies, ex-hibiting a lowpass t-MTF as observed in the auditory cortex.


A Neuronal Correlate of Octave Similarity and Discriminationin the Auditory Midbrain of GerbilsMichael Ochse, Peter Baumhoff, Gerald LangnerNeuroacoustics, Darmstadt University of TechnologyComplex signals, that are important in human and animal com-munication, are mostly harmonic and periodic signals. In additionto the frequency analysis of the cochlea the periodicity is pro-cessed by a time analysis in the central auditory system. In ourexperiments we used awake gerbils. We investigated Neurons inthe central nucleus of the inferior colliculus (IC) of Gerbils for theirselectivity to periodic amplitude modulations. We discovered thatmost neurons in the IC with a good tuning to a best modulationfrequency (BMF) show also responses to multiples of their BMFshortly after the onset of the stimulus. Coincidence detectionbetween delayed signal representations is appropriate to explainsuch comb-filter like modulation transfer functions (MTF). Afterstimulus onset these harmonic responses are suppressed result-ing in a band pass shaped MTF and a major peak at BMF. Byiontophoretic application of inhibitory receptor antagonists andexamination of slow neuronal reactions, we were able to show aninhibitory input to these coincidence detector neurons, suppress-ing activity for half of the BMF period between the coincidences.This inhibition, which is phase coupled to the envelope of the


signal, leads to a low pass shaped MTF, by suppressing the re-action if the modulation frequency of the acoustic signal is twiceore more of the neurons BMF. The combination of both mecha-nisms, coincidence detection (high pass) and phase coupled in-hibition (low pass) can explain the commonly observed tuning ofIC-neurons to one BMF. Supported by the Volkswagen Founda-tion


Effect of Aspirin on the Temporal Effect in SimultaneousMasking with On- and Off-Frequency MaskersSophie Savel, Sid BaconArizona State University, Dept of Speech and Hearing Science,Psychoacoustics LaboratoryThe threshold for a brief signal can be 10-20 dB higher when it isat the onset than at the temporal center of a longer masker. Thistemporal effect with broadband maskers is thought to depend onthe input-output function of the basilar membrane, which is linearat low and possibly high levels, but compressive at moderate lev-els. The elevated threshold near masker onset (which occurs atmoderate levels) is thought to reflect compression of the signalwhereas the decrease in threshold over time is thought to reflecta decrease in that compression. Consistent with this are findingsthat temporary or permanent cochlear hearing loss reduces thetemporal effect by reducing threshold at onset. A temporal ef-fect with off-frequency maskers also exists, although the role ofcompression there is less clear. The purpose of this study wasto examine the role of compression on the temporal effect withon- and off-frequency maskers by studying the effects of aspiriningestion. The signal frequency was 1730 or 4000 Hz and themasker was 10 ERBs wide and centered at the signal frequencyor 500 Hz wide and positioned above the signal. Despite somevariability, aspirin tended to reduce thresholds at masker onsetwhen the level of the signal was moderate, but not when it washigh. Aspirin had no effect on thresholds when the signal was atthe temporal center of the masker. These effects were observedfor both maskers, suggesting that compression plays a role in thetemporal effect for both.



Effects of concurrent and sequential streaming in comodu-lation masking releaseTorsten Dau, Stephan Ewert, Andrew OxenhamCentre for Applied Hearing Research, Acoustic Technology,Ørsted-DTU, Technical University of DenmarkComodulation masking release (CMR) refers to the reduction inthe masked threshold of a signal due to the presence of flankingnoise bands, which share the same pattern of amplitude fluctua-tions as the on-frequency noise masker. An unresolved issue isthe extent to which CMR reflects within- and/or across-channelprocesses. This study addresses the question by assessing theinfluence of auditory grouping cues on CMR. Perceptual segrega-tion of the on-frequency masker and the flanking bands was ma-nipulated by (i) introducing an onset/offset asynchrony betweenthe masker and the flanking bands, or (ii) introducing precursoror following flanking bands. This was done for spectral configura-tions where the flanking bands were presented relatively close tothe on-frequency band or were widely separated in frequency.In conditions where the flanking bands were close to the on-frequency band, manipulating perceptual segregation had littleeffect on thresholds. In contrast, when the flanking bands werewidely separated, CMR was abolished in conditions promotingperceptual segregation. As perceptual segregation should notaffect within-channel processes, the differential effect of segre-gation cues may provide a functional definition of within- andacross-channel CMR. Also, as ”true” CMR is generally associ-ated with across-channel processing, the strong influence of per-ceptual grouping cues places strong constraints of physiologicalmodels of CMR.


Discriminating temporal loudness patterns in the absence ofoverall level cuesTina Plank, Wolfgang EllermeierInstitut für Experimentelle Psychologie, Universität RegensburgTo investigate the capability of the auditory system to discrim-inate the temporal ’shape’ of short non-stationary sounds, in aOne-Interval-Forced-Choice procedure, samples of white noiserandomly fluctuating in level were presented in two patterns inrandom order: one containing a distinct level increment at the be-ginning of the stimulus (on the 2nd of ten stimulus components),the other containing that increment at the end of the stimulus (onthe 9th of ten stimulus components). The subjects’ task was to


discriminate between these two kinds of ’loudness profiles’, pre-sented in a ’short condition’ (temporal segments of 10 ms dura-tion) and a ’long condition’ (temporal segments of 20 ms dura-tion). The data of three subjects, who all completed 6400 suchtrials, show that the auditory system is able to identify the shapeof these loudness profiles, even in the case of very short stim-ulus components of only 10 ms. Applying COSS-analysis [B.G.Berg, J. Acoust. Soc. Am.,86,1743-1746 (1989)] to the data,weights were assigned to each stimulus component, yielding ameasure for the strength of the influence that each segment hason the listener’s decision. The stimulus patterns turn out to bereflected in the shapes of the weighting functions, assigning highpositive weights to the incremented component and low or neg-ative weights to the non-signal components. The results confirmthe assumption that the auditory system is capable of analyz-ing individual stimulus components selectively with high temporalresolution, when it is required by the task given.

Tu. 17:10 Arp 2 Change detection and repetition . . .

Is the auditory continuity illusion based on a change-detection mechanism? A MEG studyDaniel Pressnitzer, Richard Ragot, Antoine Ducorps, DenisSchwartz, Sylvain BailletIRCAMThis study investigates neural correlates of the auditory conti-nuity illusion, using the magnetoencephalography brain-imagingtechnique (MEG). Four types of sounds were presented to lis-teners: 1) a continously amplitude-modulated noise; 2) the samemodulated noise interrupted by a brief silent gap; 3) the mod-ulated noise interrupted by a louder, unmodulated noise burst;4) the unmodulated noise burst alone. In condition 3), listenersreport hearing a continous modulation even though it is physi-cally interrupted by the unmodulated noise burst: a case of il-lusory auditory continuity. A whole-head MEG system with ax-ial gradiometers (CTF Omega 151) recorded brain activity whenlisteners attended passively to the stimuli. Here we report anal-ysis on individual channels, averaged across 15 listeners. Theamplitude-modulated noise produced a correspondingly modu-lated magnetic activity, the well-known auditory steady-state re-sponse. However, the illusory modulation did not produce sucha steady-state response. A possible neural correlate of the illu-sion was found in transient evoked responses. When a physicalchange in the stimulus was linked to a perceptual onset, oscil-latory activity in the gamma-band range as well as slow evokedpotentials were observed. In the case of the illusion, where a


physical change in the stimulus was not accompanied by a per-ceptual onset, these neural responses were largely reduced orabsent. An interpretation of our findings is that the continuity il-lusion is based on the suppression of a putative onset/changeprocessing mechanism, involved in the perceptual organisationof auditory scenes.


Pre-attentive change detection as indexed by the mismatchnegativity event-related potential componentErich Schröger, Stefan BertiInstitut für Allgemeine Psychologie der Universität LeipzigThe mismatch negativity (MMN) is a component of the event-related brain potential elicited by an irregular sound occurring ina series of sounds setting up a regularity. It peaks between 100and 250 ms after onset of the irregularity. EEG, MEG, and fMRIdata indicate that it is mainly generated in temporal and partly infrontal cortex. It is explained by a memory comparison mecha-nism in which the sensory representation of a current sound ismismatched to a neural model of the regularity established bythe preceding stimulation. In other words, from the elicitation ofMMN it can be inferred that a regularity has been established inthe brain and that a deviancy from this regularity has been de-tected. Importantly, MMN is even elicited when the sounds arenot attended. This pre-attentive scanning of the auditory environ-ment for deviations from some regularity enables the involuntaryswitching of attention towards potentially meaningful events. In-terestingly, MMN is not only elicited by ”simple” deviations wherean isochronous sequence of identical sounds is interrupted butalso by the violation of abstract rules, and it even has some ex-trapolatory power. Thus the pre-attentive change-detection sys-tem underlying MMN reveals a considerable degree of adaptivityand may be regarded as an intelligent system operating at sen-sory level.


Informational masking and pitch memory: Perceiving achange in a non-perceived toneLaurent Demany, Christophe RamosLaboratoire de Neurophysiologie, UMR CNRS 5543, BP 63, Uni-versité Bordeaux 2Listeners were presented with 300-ms ’chords’ of five syn-chronous pure tones, followed after a silence (0.5 - 8 s) by asingle pure tone. The frequencies of each chord’s componentswere selected randomly, but were constrained to be spaced by


intervals of at least 6 and at most 10 semitones. In one exper-imental condition (’up/down’), the single tone following a chordwas 1 semitone higher or lower than one of the chord’s threeintermediate components; on each trial, the corresponding com-ponent was selected randomly and the task was to indicate thedirection in which its pitch was changed. In another condition(’present/absent’), the single tone following a chord was eitheridentical to one of the three intermediate components or halfwayin frequency between two components; the task was to indicate ifthe single tone was present in the chord or not. Performance wasmuch better in the ’up/down’ condition than in the ’present/absent’condition. Yet, an opposite trend would be expected if it waspossible to hear out the individual components of the chords.The listeners typically reported that, in the ’up/down’ condition,they could perceive pitch changes without perceiving the pitcheswhich had changed. The ’up-down’ task was not markedly moredifficult when the chord and the following tone were presentedto opposite ears than when both stimuli were presented to thesame ear. These results provide strong evidence for the exis-tence of pitch (or spectral) change detectors at a central level ofthe auditory system.


Auditory Sensory Memory for Random WaveformsChristian KaernbachInstitut für Allgemeine Psychologie der Universität LeipzigThe memory of auditory random waveforms (i.e. noise) is a spe-cial case of the auditory memory for sensory information. Theexperiments reported here evaluate the dynamics of this storagesystem as well as the interactions with new input. Periodic wave-forms can be discriminated from uncorrelated noise by naive lis-teners up to a cycle length of 20 seconds, with the major declinein performance between 5 and 10 seconds. Even single repeti-tions of a piece of the waveform can be detected up to a stimu-lus onset asynchrony of 6 seconds. The capacity of this storagesystem is limited to a few items of in total a few hundred millisec-onds length. Within this capacity, however, items do not interferestrongly. These results are compatible with the view that audi-tory sensory memory is a modality-specific module of short-termmemory.



Short-term memory for temporal envelopesChristine Moroni, Laurent Demany, Christian LorenziLaboratoire de Psychologie Expérimentale - UMR CNRS 8581,Université René Descartes Paris 5Short-term memory for the modulation frequency and intensity ofsinusoidally amplitude-modulated (SAM) white noises was inves-tigated in forced-choice discrimination experiments conductedwith 4 listeners. The two stimuli presented on each trial lastedabout 1.25 s and were separated by a variable delay D. Modu-lation frequency discrimination was assessed for an average fre-quency value of 8 Hz, with a fixed modulation depth of either 12% or 100 %. Intensity discrimination was assessed for an aver-age level of 75 dB SPL, using a modulation frequency of 8 Hz anda 100-% depth. In each case, a roving procedure was employedin order to minimize the influence of context coding. Initially, fre-quency and intensity discrimination thresholds [P(C)=0.75] weremeasured while D was fixed at 0.25 s. The corresponding phys-ical differences (in % or dB) were then constantly presented at 6values of D: 0.25, 0.5, 1, 2, 4, or 8 s. For both intensity and fre-quency discrimination, the decline of sensitivity (d’) as a functionof D was quite slow. For frequency discrimination, decreasingdepth from 100 to 12 % did not have a marked effect on the de-cline of d’ as a function of D, although this degraded the initialdiscrimination threshold by a factor of about 2. Taken together,these results suggest that there is little information loss in theshort-term memory representation of simple temporal envelopes.Moreover, the data concerning frequency discrimination appearto be inconsistent with the model of perceptual memory proposedby Kinchla & Smyzer (1967).

Tu. 8:30 Arp 3 Silicon and other microphones

Silicon Microphone Development at Infineon TechnologiesAGStefan Barzen, Michael Brauer, Marc Fueldner, Alfons DehéInfineon Technologies AGWithin the framework of the nationally funded project ”SiliconMicrophones for Array Applications”(BMBF 16SV1273), whichstarted in Feb. 2001, Infineon Technologies AG has developedSilicon micromachined condenser microphones for applicationsin automotive and hearing aids. The advantages of Silicon Micro-phones compared to electrets are their ability to sustain temper-ature in excess of 300◦C, their long term stability and their goodreproducibility in terms of sensitivity and noise. These are impor-tant facts for precise matching of microphones in array solutions.


This paper will show how Silicon microphones are processed ina standard six inch CMOS fab. Innovative surface and bulk mi-cromachining processes have been developed to realise the mi-crophone functionality. Basically, the microphone consists of athin poly-Silicon membrane electrode which has precise distanceof about 2µm to a highly perforated counter electrode. Monolith-ically integrated microphones as well as two chip solutions havebeen developed. Especially the hybrid integration opens up awide spectrum of applications in terms of signal conditioning. Mi-crophones have been realized with sensitivities of up to 30mV/Paat 2.5V bias and without amplification. These microphones showsuperior noise equivalent sound pressures of only 25dB(A). Withthe aid of the developed simulation tools Infineon is nowadayscapable of designing microphones to a given specification. Es-pecially the surface mount device packages allow automatic man-ufacturing and reflow soldering of the devices.


Simulation of acoustical and electrical Performance of Sili-con MicrophonesMichael Brauer, Alfons Dehé, Marc Füldner, Rainer LaurInfineon Technologies AGThis paper presents a microphone model, which allows simulat-ing acoustical and electrical behaviour. Furthermore the simula-tion results compare very well with measurements. The modelis based on a SPICE network comprehending the possibility touse it with different simulation tools like PSpice or Spectre. Sothe benefit is a surrounding area which is compatible with mostcircuit design areas and the acoustical behaviour can smoothlybe integrated into the simulation. For example a complex circuitwith integrated filters and amplifiers to analyse the microphoneoutput signal can be simultaneously simulated with the acousticsto match a given specification. The model includes the entire sil-icon microphone system with all subsystems like the acoustics,the mechanics, the mechanical-electrical transducer, the circuitincluding the parasitic capacitances and the housing of the mi-crophone. The acoustical-mechanical simulation depends on theelectromechanical analogy between mechanical, acoustical andelectrical systems. Therefore it is possible to describe the sen-sitivity, the noise and particularly the signal-to-noise ratio consid-ering the acoustical and electrical parts of the microphone. Theverification of the model with different bias voltages and variousload resistors for the microphone capacity on the one hand andthe modification of the sound inlet port on the other hand showan excellent agreement between simulation and measurement.


Thus a variation of electrical or mechanical parameters is accu-rately considered in the model.


Development of Directional Silicon MicrophonesMarc Füldner, Alfons DehéInfineon Technologies AGIn hand-free applications and hearing aids, microphones withdirectional characteristic are used for improved signal-to-noise-ratio. Basically there are two different approaches to sepa-rate a localized speech source from a noisy environment. Mi-crophone arrays employ two or more omni directional micro-phones with electronic processing of the directivity-dependenttime delay between the signals. For smaller devices, an acous-tical phase-shifting element between two sound ports of a singlemicrophone provides a directivity-dependent differential soundpressure. This paper presents microphone packaging conceptsin Surface Mount Technology, electro-acoustical modelling andmeasurement results of directional silicon microphones using asingle-microphone approach. Microphones on a PCB (printedcircuit board) with premolded cap as well as microphones in apremolded package with metallic cap have been tested and opti-mized. The front sound port is a drilled hole in the bottom of thepackage below the microphone chip. The acoustical impedanceof the rear sound port which specifies the needed phase-shiftis adjusted by different damping materials and very small holesrealized by chemical etching and laser cutting, respectively. Ac-cording to the formal analogy between mechanical, acousticaland electrical systems, an equivalent circuit representation of thedirectional microphone was composed. In this technique, mass,stiffness and damping are represented by electrical inductors, ca-pacitors and resistors. The time delay between the signals enter-ing the front and rear port was included by a transmission line el-ement. Based on the directional microphone model, the design ofthe rear port was optimized regarding its acoustical impedance,resulting in measured signal attenuations up to 19 dB at 1 kHz.


MEMS Packaging - Technological Solutions for a Si-MicrophoneKarl-Friedrich Becker, Mathias Koch, Tanja Braun, Volker Bader,Rolf Aschenbrenner, Herbert ReichlFraunhofer IZM BerlinMicro Systems and Micro Devices play an important role in to-day’s high tech products. They are used as acceleration sen-sors for airbag control, as piezo actuators for high resolution


print heads, as micro pumps for high precision chemical/medicaldispensers or as silicon microphones for smallest hearing aidapplica-tions. In order to facilitate the use of such fragile de-vices, packaging of these structures is on major issue. Due tothe cost and yield issues associated with this process step, sig-nificant evolution on top of the mi-croelectronic packaging tech-niques is required. MEMS packaging fulfils a crucial role withinthe function of the MEMS device. Besides the electrical inter-connection, the package provides mechanical protection, mediaseparation or coupling (e.g. pressure), signal conditioning, etc.,it must enable the resulting package to be manufactured and as-sembled at low cost. Also, high reliability requirements even un-der harsh conditions (e.g. oil sink with extreme tempera-ture dif-ferences and aggressive ambient) must be fulfilled in order to beaccepted in the market for high tech solutions. Within the projectInFON a packaging technology for stress sensitive MEMS de-vices has been developed, that allows the cost effective packag-ing of a silicon microphone. The development of the packagingtech-nology is described in detail from concept development andmaterial selection to manufacturing process development and re-liability characterization.


Design Support and Development of Miniaturised Si-Microphone PackagesJohann-Peter SommerFraunhofer IZM BerlinNumerical sensitivity analysis by means of finite elements (FE) isuseful to reduce cost and time to market by minimising real testsand expensive redesign. Within the research project ’InFON’,funded by the German government (BMBF), the FE methodol-ogy was improved and applied to miniaturised Si-microphones,to be starting already at an early stage of the design process.Several material combinations for board, adhesives, and casewere investigated in order to evaluate the pre-stress stability ofthe chip membrane, which is influenced by the sequence of man-ufacturing steps and their temperatures due to the unavoidablethermal mismatch between different materials. Besides them, themembrane deflection under electrostatic loading had to be char-acterised regarding the pre-stress state in the membrane and thereal topology of the backplate electrode. Reliable numerical re-sults can only be expected based on reliable material data forall components. Therefore, the visco-elastic behaviour of severalimportant adhesives has been characterised, taking into accountthermal as well as time dependencies of the parameters. Subse-quently, the contribution gives an impression about the advances


which can be expected to be made with the help of FE techniquesin early design steps of innovative and advanced microelectronicsystems, and pinpoints the numerically recommended solutionfor Si-micophone packaging.


Measurements of Silicon Microphone Arrays in Hearing AidsChristian Weistenhöfer, Torsten NiederdränkSiemens Audiologische Technik GmbHMiniature electret microphones are the state-of-the-art hearingaid transducers. In modern hearing aids several single micro-phones are combined to directional microphones in order to geta higher speech intellegibility in noisy environments. For this pur-pose it is essential to have a high directivity which can only beachieved if the microphones are matched accurately. Silicon mi-crophones a priori have low interindividual tolerances since theyare manufactured using silicon micromechanic processes. Inprinciple they are very well suited for directional microphones.If the microphones are placed in one housing, the hearing aidmanufacturing process can be simplified (e.g. reduction of lizwires). In the talk prototypes of silicon microphone arrays appliedin hearing aids will be presented. These prototypes have beendeveloped within the joint research project InFON granted by theBMBF (Federal Ministry of Education and Research). Results ofbasic measurements (e.g. sensitivity and equivalent input noise)will be dicussed as well as results of directional microphone re-lated investigations.


Unidirectional Silicon Microphones: Testing And Basic Mod-ellingHelmut KrügerPeiker acustic Gmbh&Co.KGUnidirectional Silicon Microphones: Testing And Basic ModellingAny microphone intended for automotive communication pur-poses must fulfill a long list of acoustical and electrical specifi-cations, i.e. directivity,immunity and a purpose-built output con-figuration. Silicon microphonesoffer many advantages in respectof vibrational, electrical and thermal immunity, but for direct re-placement of existing parts, the desired directivity pattern has tobe designed inside a micromechanical environment. This paperis intended to show the early iteration process of measurementand modelling with first production samples.



Directional Microphones in Automotive Applications (Adap-tive Beamforming)Patrick VicinusPeiker acustic Gmbh&Co.KGHandsfree communication in car environement becomes moreand more common for the general public. The acceptance de-pends directly from the achieved audio-quality during phoningand error rate in speech recognition. Signal processing can en-hance these factors. To take advantage out of a multi channelprocessing, this paper will present a dual silicon microphone ar-ray and its algorithm, which combines adaptive beamforming anddual channel noise cancellation. It analyses measurements ofthe microphones and the array in various scenarious of car en-vironment and discusses the benefits of directional silicon micro-phones in automotive array applications.


Analytical simulation of silicon condenser microphonesS. Junge, L. Tebje, W. Lang, W. BeneckeUniversity of Bremen, Institut für Mikrosensoren, -aktuatoren und-systeme (IMSAS)G.M. Sessler [1] introduces an electromechanical equivalentcircuit diagram for a capacitive transducer with a perforatedbackplate. This paper describes an extended analytical modelfor silicon condenser microphones to calculate e.g. receiv-ing and transmitting sensitivity, membrane deflection andinput impedance. Electrical and mechanical elements of thetransducer can be integrated into the same equivalent circuitemploying a transformer.The membrane is modeled as a spring-mass system usinga lumped element approach. In addition, dynamic effects asthe mechanical reaction force of the air-gap and flow losses inthe air-gap as well as the acoustic holes in the backplate areconsidered [2].All essential design parameters of the device are taken intoaccount in the model with a detailed examination of the influenceof the parameters on sensitivity and input impedance. Figure1 shows the equivalent mechanical parts of the device. Finally,an optimized backplate perforation is proposed to minimize flowlosses of the air flowing through air-gap and perforation holes[3].1. G.M. Sessler, Acoustic 1, Lecture, University of Darmstadt,19982. L. Tebje, S. Junge, A. Buhrdorf and W. Benecke, An Analytical


Model for Low Frequency Capacitive Ultrasonic Transducers andCondenser Microphones3rd Workshop on Micromachined Ultrasonic Transducers (MUT2003), Lausanne, 20033. A. Buhrdorf et. al., Capacitive Micromachined UltrasonicTransducer (cMUT) Array for The Frequency Range Below500 kHz, Proceedings of the IEEE International UltrasonicSymposium, 2000, San Juan, Puerto Rico, p.915


Design and Application of a Low-Cost Microphone Array forNearfield Acoustical HolographyJoachim Bös, Lothar KurtzeFraunhofer Institute for Structural Durability LBFAn 8x8 microphone array consisting of 64 low-cost microphoneswas developed at the Department of Mechatronics and Ma-chine Acoustics, Darmstadt University of Technology, and ap-plied to nearfield acoustical holography (NAH) measurements atthe Fraunhofer Institute for Structural Durability LBF. Since micro-phone arrays usually require a large number of microphones forNAH to cover a reasonable frequency range, it is particularly at-tractive to reduce the cost per microphone. A silicon microphonewas chosen because it is very cheap (approx. 18 Euros includingpreamplifier vs. 350 to 500 Euros for ”professional” array micro-phones - a factor of about 25!), temperature and shock resistant,and insensitive to structure borne noise. It has a flat frequency re-sponse, which was confirmed by comparisons with a Brüel&Kjaermicrophone. The dimensions of the array (1.4 m x 1.4 m) result ina lower frequency limit of approx. 250 Hz, the microphone spac-ing (currently 200 mm, adjustable to smaller values) leads to anupper frequency limit of approx. 850 Hz. The microphone array isused to perform NAH measurements on various test objects us-ing a Scadas III front-end and Cada-X software, both from LMS.The results of the NAH predictions are verified by sound pres-sure measurements (sound pressure distribution), laser vibrom-eter measurements (velocities at the source), and sound intensitymeasurements using a 2D intensity probe.


Free-Field Calibration of Microphones and Sound Level Me-ters in an Anechoic ChamberHolger Nicklich, Heinz WeißingSPEKTRA Schwingungstechnik und Akustik GmbH Dresden


More often than not, the results of acoustic measurements havefar-reaching consequences for technical, financial and legal de-cisions - that is why high precision is required. Careful calibra-tion of the employed measuring instrumentation is one of the ba-sic prerequisites to achieve this goal. The paper starts with anoverview of the methods available for sound pressure calibration,assessing their relevance to practical application. In a secondpart the free-field acoustic calibration system is introduced thatSPEKTRA, Germany developed for the calibration of measuringmicrophones and sound level meters by the method of compar-ison in an anechoic chamber. The method presented is of fun-damental importance, as it is the only one that applies the typeof sound field on which the standardized requirements for soundlevel meters are based.

Tu. 16:50 Arp 3 Speech in vehicles

Realtime Performance of Acoustic Echo Canceler and Post-filter in the Car EnvironmentGerald Enzner, Dirk Mauler, Peter VaryRWTH AachenA very simple and elegant signal processing solution to theacoustic echo control problem has been presented recently [1].This approach is based on the purely statistical adaptation of anacoustic echo canceler and a postfilter for residual echo suppres-sion. A double talk detection is not required for the stability of thisalgorithm. We have now used the algorithm to reduce the acous-tic echo of hands-free telephones in the car environment. In thispaper we present the results of the performance evaluation on thebasis of our realtime implementation. It turns out that the mainstrength of the algorithm is the duplex ability, i.e. the fast androbust adaptation in the double talk situation. [1] Gerald Enznerand Peter Vary, ’Robust and Elegant, Purely Statistical Adapta-tion of Acoustic Echo Canceler and Postfilter’, Proc. IWAENC2003.


Evaluating Speech Recognition Performance in the Car - APragmatic ApproachMarkus LiebVolkswagen AGDuring the development of voice-controlled applications the con-tinuous monitoring of the speech recognition performance fromthe lab into the final product is of crucial importance. There isa gap between large-scale off-line automatic speech recognition(ASR) tests being run in the lab on pre-recorded speech mate-rial, and tests with real speech uttered by test persons in the


target cars under realistic, e.g. driving, conditions. Both tests arenecessary and conclusive, yet not sufficient for objective perfor-mance comparisons e.g. of different ASR installations. To eval-uate ASR performance in a transferrable and repeatable man-ner for different cars at different point of time without the need toassemble test persons for every new test, a different approachis proposed with this paper. Starting from pre-recorded speechmaterial covering all sorts of variations like gender, accents, age,and background noise conditions, we aim for a reproducable cal-ibrated playback mechanism in the car. Such controlled playbackcomprises the ASR performance evaluation in an objective man-ner and especially allows for the comparison of different systems,e.g. in different cars, based on the same speech material. Wepresent the experimental set-up for such performance investiga-tions, describe the test procedure and give insight into resultsfrom the field.


Robust adaptive beamformer for automotive applicationsMarkus Buck, Tim HaulickTemic SDS GmbHThe application of microphone arrays for speech acquisition incars promise significant signal improvement compared to sys-tems operating with a single microphone. By applying beam-forming algorithms a spatial selectivity can be achieved whichpermits the suppression of noise signals coming from directionsother than the speaker direction. Adaptive beamformers offer apotentially superior performance to fixed beamformers particu-larly in the case of time varying sound field characteristics or inthe case of coherent noise (such as interfering speakers, loud-speaker signals, etc.). However, for real-world applications adap-tive beamformers hold the risk of severe signal degradation. Dis-turbances such as an imprecise steering direction, mismatchedmicrophones or reverberation due to multipath propagation maycause the adaptive beamformer to cancel out the desired sig-nal. This behaviour is known as ”Signal Cancellation” effect. Thiscontribution describes a subband adaptive beamformer in GSCstructure which is optimized for car environments. In order to pre-vent signal cancellation the system comprises a combination ofseveral robustness methods which have proven to be effective forpractical application.



Convolutive Blind Source Separation for Noisy MixturesRobert Aichner, Herbert Buchner, Walter KellermannUniversity of Erlangen-NurembergRecently, we presented a blind source separation (BSS) frame-work for convolutive mixtures. The resulting algorithms are suit-able for separating speech signals in real-world environmentswith room impulse responses modeled by long FIR filters of sev-eral thousand taps. In this paper we extend the BSS model tothe case when noise is present. In the case of arbitrary noisesources, suitable noise estimation methods have to be utilizedto obtain noise-robust BSS algorithms. Here, we combine afrequency-domain BSS algorithm based on second-order statis-tics with a bias removal technique utilizing minimum statistics.This leads to improved separation performance for noisy envi-ronments. Experiments conducted in a car environment showthe effectiveness of our method.


Speech Recognition for Mass-Production VehiclesEike GegenmantelScanSoftIn many areas speech is a considerable choice for user inter-faces to devices and services. In a vehicle, speech control hasspecific value: It is a true additional channel to the many alreadyexisting buttons and displays. Speech control does not need thehands, they can stay at the steering wheel, and with an acousticfeed back, the eyes are not forced to a display and remain on theroad. A new way of control is available for navigation systems,telephone, car audio, on-board computer and many more. Thereare high demands on speech control in vehicles: The noise levelis comparably high, the underlying electrical devices have to fulfilhigh physical requirements, and the cost pressure is very toughwhen targeting the mass market. This presentation will describehow modern speech recognition technology fulfils these require-ments already today. It will give an overview how the combinationof microphone position and direction, and electronic and algorith-mic filters copes with the acoustical conditions. The presenta-tion will also show that mature digital signal processors fulfil thephysical requirements at low cost, however, at another price: So-phisticated software engineering is needed to prepare complexspeech recognition and filter algorithms in a way that - despitelimitations of memory space, computing power and precision -the required quality of speech control is still ensured.



Challenges in Mobile Hands-free System OptimizationFrank Kettler, Hans Wilhelm Gierlich, Frank RosenbergerHEAD acoustics GmbHBuilt-in car hands-free telephones may consist of different com-ponents consequently leading to a heterogeneous system de-sign. Each component like the microphone (or microphone arrayrespectively), the hands-free unit itself and sometimes the mobileintegrated additionally introduce various kinds of signal process-ing. This may even lead to cascaded algorithms providing thesame kind of, or at least comparable signal processing in orderto improve speech quality. A typical example is the noise reduc-tion which can be found in the microphone array (beam form-ing, algorithmic noise reduction), additionally in the hands-freeunit and in the integrated mobile. In order to guarantee a goodspeech quality for the complete system it is absolutely necessaryto choose the parameter settings of these algorithms according tothe characteristics of the cascaded systems. Typically these cas-caded systems have been optimized independently of each otherand the combination of the systems do not necessarily lead to asufficient speech quality of the whole system. This presentationshows some practical examples how single parameters - and asa final result - the complete system can be optimized.

We. 8:30 Schweitzer Car acoustics IV

Evaluation of vibration perception in passenger cabinMichael Bellmann, Hermann Remmersitap GmbH - Institut für technische und angewandte PhysikThe human body is exposed to various whole-body vibrationsfrom different sources, e.g., at working place in industry or indaily life traffic. The comfort or discomfort caused by interiorsound and vibration in a passenger cabin is an important prop-erty which became more and more important for the acceptabilityof transport facilities over the last years, especially in automotiveindustry. In this study, vibro-acoustic multi-channel recordingsare measured in different types of passenger cabins in vehiclesand aircrafts. It would be very advantageous knowing the prop-erties of the noise and vibration signals that are fundamental forquality assessments. This study focuses on vibration perception.However, the vibration signals are measured at the man-machineinterfaces between the vibrating part of the machine (e.g., theseat) and the human body. On the basis of representative spec-tra typical vibration characteristics of different types of exposurein cabins are discussed, like relevant frequency and magnitudeselectivity aspects. Furthermore, new and reliable possibilities to


evaluate and to describe vibration perception in passenger cab-ins are pointed out. The discussion refers to experiences and re-sults from basic experiments which take into account sinusoidal(deterministic) excitation as well as stochastic broadband stimuli.The benefit is to improve the objective description of subjective(dis-) comfort caused by vibrations. However, the advantage ofmore and better information and knowledge about the perceptionof vibrations allows to improve human response to vibration mod-els (HRVM) so that ’comfort’ would increase and the annoyanceexperienced from vibrations would be reduced.


A sound Perception Approach inside a mechanical ShovelCabinNacer Hamzaoui, Etienne Parizet, Pierre LoisyLab. Vibrations Acoustique, INSA Lyon - Bât. 303Acoustic studies usually consist in carrying out either an experi-mental diagnostic or vibro-acoustic computations allowing to un-derstand the physical functioning of the noise source, and thenin making modifications respecting a specification developed byspecialists. The perceptive analysis part including the users ofthe product still remains a rather low one in these studies. Per-ceptive approaches can complete physical studies in a very use-ful way, allowing to reach a target expected by customers morequickly. The subjective result can be linked to physics trying tocorrelate it with one or several indicators representing the pro-cessed signals. This correlation then allows to identify the physi-cal parameters characterizing the studied noise annoyance, andthus to identify annoying frequencies and annoying sources, andincrease the efficiency of the resolution of the formulated prob-lem. In this communication, the application of a global process ofsound perception on an industrial object is presented with the willto reach the targeted physical objectives. This work is stemmedfrom a study carried out in the frame of a collaboration with theVolvo Compact Excavators company, a manufacturer of mechan-ical shovels. The objectives determined within this collaborationhave been : 1. On a complete machine, the manufacturer wantedto have a predictive model of sound annoyance at his disposaland identify the elements of the machine contributing to annoy-ance so as to establish a hierarchical approach of noise reductioninside the cabin. 2. Definition of frequency bands said to be use-ful, intervening in sound perception and thus allowing to choosea physical modeling method adapted to the problem.



Interior Vehicle Sound Composition: Wind Noise PerceptionMarkus Bodden, Gerd Booz, Ralf HeinrichsIngenieurbüro Dr. BoddenInterior vehicle sound is composed of three major components:engine, road&tires, and Wind noise. The role of the balance ofthese three components was investigated first. The main focuswas then set on wind noise perception. A typical characteris-tics of wind noise are temporal variations caused by the outdoorand driving condition, which are perceived as signal fluctuations.Customer perception of these fluctuations was investigated bymeans of listening studies and a customer forum.


Audibility of resolved tonal components of gear noise in pas-senger car cabins by trained listenersAxel Mors, Werner Deutsch, Holger WaubkeZF Friedrichshafen AGProfessional acoustic engineers as drivers especially of middle-, upper- and premium class cars are extremely sensitive to anyacoustical signal detectable in the passenger cabin for qualitycontrol. They have to be categorized as highly trained listen-ers due to their long term experience in driving different modelsof cars. Even quite low level tonal components of gear noisecan be separated by the ear from engine noise because of theirhigher order and their different modulation characteristics. Al-though the gear tone components are temporally masked by am-plitude modulated engine noise, they are perceived as continu-ous emissions. They build a continuous auditory stream becauseof psychoacoustic phenomena such as stream segregation andthe picket fence effect. A numerical model combining simulta-neous masking and modulation effects is under development inorder to evaluate and predict subjective reactions. Acoustic engi-neers with high listening experience have been tested extensivelyin pre-tests, classifying different sound segments depending onspeed and gear. The results confirm the importance of the inter-action between masking effects and the modulation characteristicof both, the highly modulated engine noise and the slowly varyingtonal components of the gear. The over all detectibility has to beassumed at the levels of human auditory sensitivity under closeto laboratory conditions for highly trained listeners.



Wavelet Transformation and gear noiseDaniel Bader, Peter Holstein, Heiko MarxTechnische Universität IlmenauThe investigation of gear noise emitted by automotive tooth gearshas gained increasingly in importance. The activities are focusedon the reduction of acoustic emissions and the detection of gearfailures. For these purposes, standard procedures of joint-time-frequency-analysis are applied, based on the short time fouriertransformation. With this method important information resultingfrom non-stationary events are often detectable only with diffi-culty. Many problems also result from the large amount of dataProduced by sampling in audio-quality when post-processing al-gorithms are applied for further data treatment. In many cases,the amount of data prevents real-time analyses with conventionaltools, which are therefore only of limited use for quality inspec-tion. For this reason, a wavelet analysis treatment for streamingdata has been implemented on DSP boards in real time mode.The method is tested on several types of tooth failures and com-pared with wavelet analysis in post-processing mode and con-ventional joint time frequency analysis. The objects under inves-tigation were spur gears of balancer systems. These units areresponsible for compensation of second-order inertia forces andrun at a speed of up to 12000 rpm. It is demonstrated that non-stationary methods such as the proposed wavelet techniques aresuited to recognize and in particular to classify tooth failures toa better extent than the conventional JTFA analysis techniques.The system is designed to use FFT- and wavelet-based DSPtechniques in a complementary manner at the real-time level.The DSP modes are part of a general modular software systemextending over several levels.


Combustion Noise and Piston Slap Noise: Identification ofTwo Sources Responsible for Diesel Engine’s Sound Signa-tureCyril RenardLAUMSound quality of engines has become an important criteria in cus-tomer’s choice. For this purpose, car manufacturers tend to workin two ways : - noise reduction, which consist in lowering globalnoise level by decreasing ” bad ” noise components, like aero-dynamic noise or combustion noise and, - sound design whichis more about making ” good ” noise components appear. Forexample, an engine will inspire a ” sporty ” image to the audi-ence by the rise of harmonic 3 and 6 because it will sound like a


6 cylinders. This work registers in the noise reduction part, be-cause it deals with the combustion noise and piston slap noisethat are two undesirable components of Diesel engine’s soundsignature. These two sound sources appear with a very shorttime delay. Hence it is extremely difficult to identify their respec-tive contributions to global sound. In order to discriminate thesetwo contributions, we have planned an experiment which con-sists in increasing or decreasing independently the two sources.Thus, four test set-ups have been defined, namely : - low clear-ance piston + combustion turned off, - high clearance piston +combustion turned off, - high clearance piston + standard com-bustion, - high clearance piston + severe combustion. Vibrationsof the engine are then measured using accelerometers placed atdifferent areas. Then a time-frequency analysis allows us to seethe impacts in terms of frequency, amplitude and location.


Fahrzeugakustik im Diesel KaltstartNorbert Alt, Stefan Heuer, Rainer ThieleFEV Motorentechnik GmbHDas hervorragende Drehmoment- und Leistungsangebot mod-erner Dieselmotoren, kombiniert mit niedrigen Kraftstoffver-bräuchen und Abgasemissionen, lassen diese zunehmend Mark-tanteile gewinnen. Auch das Geräusch ist bei vielen Fahrzeu-gen auf einem akzeptablen Niveau. Beim Kaltstart nageln je-doch bis heute die meisten Motoren unangenehm laut. Durcheine gezielte akustische Optimierung der Kaltstartkorrekturen imSteuergerät ist eine signifikante Verbesserung möglich. Es sind,abhängig von der Basiskalibrierung, Pegelreduktionen im Innen-und Außengeräusch von 0.5 - 5 dB bei -10◦C Umgebungstem-peratur erreichbar, ohne dass Einbußen bezüglich Startbarkeit,sichtbarem Schwarz- oder Weißrauch oder im MVEG-Zyklusauftreten.


Kompensationsmöglichkeiten des Wegfalls von Fahrzeug-baustufen im Fahrzeugentwicklungsprozess durch dengezielten Einsatz von Mess- und Simulationswerkzeugen amBeispiel der BTPA (Binaurale Transferpfad Analyse)Bernd Winter, Bernhard LangeAdam Opel AGUm schneller auf die Anforderungen des Marktes reagieren zukönnen, ist eine Verkürzung der Fahrzeugentwicklungszeiten er-forderlich. Mit der Verkürzung der Entwicklungszeiten verringertsich auch der zeitliche Abstand zwischen der Verfügbarkeit derersten Prototypen und dem Beginn der Produktion. Im Zuge


der Einführung neuer Entwicklungsprozesse bei der Adam OpelAG kann es dazu kommen, dass bestimmte Fahrzeugentwick-lungsstufen wegfallen.Durch den gezielten Einsatz von Mess- und Simulationswerkzeu-gen muss diesem neuen Entwicklungsprozess Rechnung ge-tragen werden. Dies geschieht durch übertragung von Erken-ntnissen aus dem Entwicklungsprozess des Vorgängermod-ells bzw. aus Erkenntnissen von parallel laufenden Entwick-lungsprozessen verwandter Modellreihen.Anhand der BTPA (Binaurale Transferpfad Analyse) zweierverwandter Modelle, des Opel Vectra und des Opel Signum,soll beispielhaft gezeigt werden, welche Datensätze bzw. Er-fahrungswerte man zukünftig prozessübergreifend verwendenkann. Worst-Case-Abschätzungen durch die Verwendungvon Targetkurven sind dabei ein Werkzeug, um im Entwick-lungsprozess nicht vorhandene Datensätze fundiert ersetzen zukönnen.


SEA as Tool in Vehicle DevelopmentAndreas MüllerAUDI AGStatistical Energy Analysis (SEA) is a method for calculatinghigher frequency interior cavity acoustics. Application of themethod relies on high modal density subsystems, into which thewhole dynamic system must be broken. This induces a lowerfrequency bound, which is in contrast to finite element or bound-ary element methods, which are most useful, when vibrations ofstructures or fluids are dominated by individual modes. After anintroduction into the SEA theory the applicability of the methodin vehicle development will be assessed on the basis of someexamples.


A combined modelling approach for improved SEA-predictions in automotive applicationsThorsten Bartosch, Christoph Fankhauser, Michael Vorraber,Alexander GlettlerMagna Steyr EngineeringFor automotive engineers the predictive SEA with tools like Au-toSEA and the measuring method of the experimental SEA withe.g. LMS ESEA are often two worlds. SEA prediction is used tocheck well-known parameters like the sound insulation of a ma-terial/layer combination and to detect some of the main soundtransmission paths to the driver’s ear. The experimental SEAis fundamentally based on transfer functions and allows under


certain well-known SEA assumptions the calibration of internaland coupling loss factors between subsystems. A new aspect,which seems very promising, is the combination of the analyti-cal modelling and the experimental modelling in order to gain abetter simulation accuracy. This goal can easily be achieved ifthe experimental and the analytical modelling processes result inan identical subsystem partitioning. On the other hand MagnaSteyr’s practise shows that this strict modelling instruction can-not be fulfilled in daily work. Therefore special techniques formerging the two worlds are outlined in the following. Besides ex-perimental SEA it is further shown how a new hybrid FEM-SEAapproach can be used in order to improve analytical SEA models.This contribution will give a brief overview over applied SEA mod-elling techniques and then point out the power of combined sim-ulation. A strongly reduced AutoSEA model for airborne as wellas structural noise is proposed and the results are discussed.From the authors’ point of view the combined analytical and ex-perimental approach is very likely to become the SEA modellingtechnique of the future.


Interaktion Motor-Getriebe GeräuschNorbert Alt, Christoph SteffensFEV Motorentechnik GmbHDie getrennte akustische Optimierung an den EinzelaggregatenMotor und Getriebe wirkt sich im Allgemeinen auch positiv aufdas Gesamtgeräuschverhalten eines Komplettaggregates aus.Zunehmend werden die Konstrukteure bei steigenden Forderun-gen an die Geräuschminimierung jedoch mit dem Phänomenkonfrontiert, dass die als Einzelkomponenten getrennt entwick-elten, optimierten und erprobten Baugruppen im Zusammenspielunerwünschte bzw. unvorhergesehene Geräusche verursachen.Die Ursache ist darin zu suchen, dass alle Elemente der maschi-nenakustischen übertragungskette nicht unabhängige Größender Einzelaggregate, sondern abhängig von deren Zusammen-wirken im Gesamtsystem sind. Gegenstand des vorliegendenArtikels ist die Analyse der Wechselwirkungen zwischen Ver-brennungsmotor und Getriebe in Bezug auf Anregungsmech-anismen und Körperschallflüsse an einem PKW 4-Zylinder-Ottomotor mit Fünfgang-Schaltgetriebe. Zur Untersuchung wirddie gesamte Schallentstehungskette von der Anregung bis zurSchallabstrahlung betrachtet. Aufbauend auf experimentellenUntersuchungen wurde dazu ein Berechnungswerkzeug entwick-elt, das es erlaubt, die akustischen Eigenschaften des Motor-Getriebe-Verbunds abzubilden. Mit Hilfe dieses Tools könnenGesamtaggregate akustisch analysiert, beurteilt und optimiert


werden. Darüber hinaus kann der Einfluss von Design- und Pa-rameteränderungen auf das akustische Verhalten von Motor undGetriebe quantifiziert werden. Besondere Beachtung findet hierdie Biegedynamik von Kurbelwelle und Getriebewellen sowie dieAusführung des Schwungrad-/Kupplungssystems.


Antriebsstrang NVH Optimierung mit MKS/FENorbert Alt, Klaus Wolff, Eugen BraunFEV Motorentechnik GmbHObwohl die Aufgabe des Antriebstrangs lediglich darin besteht,das Drehmoment auf die Straße zu übertragen, ist die Ausle-gung durch eine Reihe von Vorgaben wie z. B. Haltbarkeit,Packaging, Akustik, Fahrverhalten sehr anspruchsvoll. Die Vor-gaben führen oft zu widersprüchlichen Anforderungen, bei de-nen man angemessene Kompromisse in Kauf nehmen muss.Die vorliegende Arbeit untersucht zwei Beispiele, bei denen Ab-striche unvermeidlich sind, und zeigt auf, wie man den best-möglichen Kompromiss finden kann. Ein Beispiel behandelt dasProblem des Getrieberasselns bei Handschaltgetrieben unterBerücksichtigung von Aspekten sowohl der Akustik als auchder Fahrbarkeit. Ein zweites Beispiel behandelt das ,Clunk-Geräusch/Vibrationen” bei Fahrzeugen mit Automatikgetriebe.Bei einem Gangwechsel im Stand von ,D zu R” oder von,P zu R” können störende ,Clunk-Geräusche” und Vibrationenauftreten. Mit Hilfe von Tools wie z. B. Mehr-Körper-Simulation(MKS) und and Computer Aided Testing (CAT) werden Opti-mierung durchgeführt. Für die MKS Methode wird ein komplettesFahrzeugmodell benötigt, bestehend aus Aggregat, Antrieb-sstrang und Chassis. Die Gummilager aller elastisch aufge-hängten Komponenten - Powertrain, Differential, Fahrschemel -werden ebenfalls berücksichtigt. Durch eine Sensitivitätsanal-yse kann der Einfluss der wichtigsten Parameter untersucht undsomit der beste Kompromiss gefunden werden. Zur Reduk-tion des Getrieberasselns werden u.a. die Einflussmöglichkeitenüber die Kupplung und Antriebswellen analysiert. Zum ,Clunk”-Phänomen werden die Ursachen und ebenfalls mögliche Lösun-gen, z. B. Gelenkspiel, im Detail erörtert.


Analysis of NVH issues in Automotive IndustryJean-Marc GuerinotCentre d’Essais Vibro-Acoustique pour l’AutomobileReducing noise and vibration is a major preoccupation for carmanufacturers. Consequently, the system suppliers have beenled to integrate this function very early in the design phase of


their products and have adapted to customer requirements. Theauthor will present some examples regarding N.V.H. & durabil-ity topics based on automotive development projects : · Modal &operational modal analysis, · Running modes studies, · Acous-tics (airborne transparency,oe), · Transfer Path Analysis, · Fa-tigue/Durability regarding vibration constraints. It will be shownthat the NVH requirements have to be taken into account as earlyas possible in the development projects and that suppliers in thisdomain have to be increasingly involved in the global car manu-facturers NVH process.


About High-Speed-Cameras in AcousticsHolger PastilléIVM Automotive Ingolstadt GmbHHigh-Speed-Cameras are normally used for car safety (airbag,head impact etc.). They are also very usefull to detect noiseproblems of elctrical drives (seat, mirror, roof). HSC are opti-mal to view the motion of parts and components, especially ro-tary motion. The application is a reasonable completition to thelaser-doppler-vibrometrie with a series of advantages, e.g. theuse under climate conditions. In the lecture will be shown thepossibilities and limitations of this method.

We. 16:30 Schweitzer Benchmarking tests in . . .

Parameters Influencing the Benchmarking of Vehicle InteriorNoiseKlaus GenuitHEAD acoustics GmbHThe sound quality of vehicle interior noise has become a very im-portant task for the acoustic engineer. As vehicles become moreand more quiet, the customer’s sensitivity to the acoustical com-fort increases. On the one hand no disturbing noises should beheard, on the other the perceived sound quality should fulfill theexpectations of the listener with respect to the sound design. Forcurrent and future needs the vehicle sound must act as a distin-guishing criterion that supports the positive image of a car. Inthis context the following characteristics of sound are useful: -sound is informative, it includes information of quality, function-ality - sound implies a certain image, such as luxury, sportive orcheap - sound may be identified, it may be used for corporate orproduct sound purposes In consequence, sound quality is an es-sential part of vehicle quality. But besides the sound the contribu-tion of vibration is not negligible. The passenger of a vehicle hasto be seen as part of a vibro-acoustical system. Consequently,


the subjective judgement of pleasantness or sound comfort is in-fluenced by both sound and vibration. For a task-oriented pro-ceeding in sound design it is absolutely necessary to considerthese aspects. The performance of benchmarking tests of ve-hicles firstly requires an analysis for which market - that meansfor which relevant customer - and in which competition this vehi-cle stands. The performance of a simulated modification in realtime for the adaptation of the acoustical features to the new targetsounds is very important.


Door Operating Sound Improvement Based On Jury TestingAnd System AnalysisPhilipp Sellerbeck, Christian NettelbeckHEAD acoustics GmbHDoor opening and closure sounds are an important factor influ-encing the quality impression received from a vehicle and aretherefore often subject to sound design. Jury listening tests usingrecorded door operating sounds can provide helpful informationnot only for benchmarking but also for deriving target sounds. Asound judged best in a benchmark can either be used as a di-rect target or provide attributes for designing a synthetic targetsound. A listeners rating of a sound depends on many additionalfactors such as personal attitude and visual feedback. Therefore,when conducting jury listening tests it is important to correctlydefine the appropriate soundscape and to take the listening en-vironment into account. A procedure for benchmarking door op-erating sounds is presented along with results and target soundattributes are derived. Psychoacoustic signal analyses that cor-respond to the results of the jury tests are introduced. In order toimprove an existing door opening or closure sound, transfer pathanalysis can be applied. A new simulation method based on atime-variant transfer model is presented. The procedure allowsindividual auralization of door sound components originating fromthe latch mechanism, striker impact, seals interaction and cavityboom, revealing the origins of unwanted noise patterns. Further-more, the influence of component modifications can be predicted,and changes can be applied that improve the overall sound withrespect to the target.



Interactive Contexts and their Contribution to BenchmarkingBrigitte Schulte-FortkampInstitut für Technische Akustik , Technische Universität BerlinIn the interior of a vehicle sound quality is a brand name. Binauralmeasurement and analysis technology is more or less standard,but general standards and parameters for sound quality still thereare none. Evaluation of noises are highly sensitive to context,but testing procedures that can include this realization are ex-ceedingly rare. Specific constellations of a general noise volumein clearly defined ambiences can characterize those ambiencesand combine the daily recurrent patterns of sound multi-factorialin the process of analysis. The evaluation of noise situations gen-erally gets interactively modified by their significance for the am-bient space. It is contingent upon the respective ponderation ofacoustic and non-acoustic modifiers which in turn constitute theenvironment to be experienced. In this frame of reference aninnovative, sensitive evaluation procedure is introduced and dis-cussed with regards to its importance for a customer-orientedbenchmarking.

We. 8:30 Schuman Physical acoustics II

Near-Field Levitation Generated by Ultrasonic Vibrations :Theoretical Analysis and ExperimentsAnne-Christine Hladky, Christian Granger, Gérard Haw, BertrandDubusInstitut d’Electronique de Microélectronique et de Nanotecholo-gie, UMR 8520 CNRS, département ISENWith a view to obtaining particular displacement conditions, suchas friction cancellation, higher speed or non contact transporta-tion, film air bearings using piezoelectric bending elements havemany advantages in comparison with conventional air bearingsystems, because they are autonomous and they take a reducedplace. In this paper, the film air bearing is provided by the flexuralvibration of a piezoelectric bimorph, made of a passive disk stuckon a piezoelectric disk. The system is excited at the frequency ofits first bending mode. For a sufficiently high vibration amplitude,an air bearing appears between the bimorph and the ground. Thegas remains stationary and is undergoing periodic cycles of com-pression and decompression. The acting principle relies upon theacoustic radiation pressure appearing in the air layer. Due to thethermal boundary layer thickness, neither adiabatic nor isothermconditions have to be used in the air layer and an intermediatecondition (equivalent compressibility) is used. With the help ofthe theoretical model, the thickness of the fluid layer is estimated


as a function of the lifted mass, the frequency and the drive level.Several prototypes are then designed using the ATILA finite el-ement code and are built. First experiments show that, if theexcitation level is greater than a given level, there are strictly nocontact between the bimorph and the ground. The air bearingthickness and its relative variations are measured with the helpof the laser vibrometer. Experimental and numerical results arecompared and discussed.


The Time Reversal Kaleidoscope: a New Concept of SmartTransducers for 3D ImagingDelphine Palacio, Gabriel Montaldo, Mickael Tanter, Mathias FinkESPCI - LOAIn real time 3D echographic imaging, the acquisition of volumicdata set requires the recordingof an echo from all the 3D region ofinterest. Traditionally, two dimensional arrays composed of sev-eral thousand of transducers are used to obtain the beam focus-ing and steering in the volume. However, the design, the con-nections and the multiplexing required by these 2D arrays aretechnically complex to realize. Here we present a completelynew approach to achieve 3D images with a very small number oftransducers using the coupling concepts of time reversal mirrorsand chaotic reverberating cavities. The small number of trans-ducers (typically 32) are glued on one surface of the solid cavity,an other face is in contact with the imaged fluid medium (like thebody). Thanks to hundred of reverberations inside the cavity, theultrasonic waves emitted by the transducers are able to focus inany point of the volumic fluid by using time reversal techniques.At each reflection, ’virtual’ transducers, images of the real onesby the reflection on the surface of the cavity, are created. As aresult, a kaleidoscopic transducer array is obtained from a smallnumber of transducer used in a time reversal mode, and allowsequivalent performances than conventional 2D matrices made ofthousands of transducers. The coupling of chaotic reverberatingcavities with times reversal techniques leads to the concept of a’smart’ transducer. First experimental 3d images obtained with apioneer prototype will be presented.



Characterization Of The Electrochemical Deposit Of A Con-ducting Polymer Film By The Means Of Acoustic Sensor(QCM)Bachar Kanj, Franck Teston, B. Pirot, M. C. Pham, Marc LethiecqGIP Ultrasons/ LUSSIQuartz crystal microbalances (QCMs) are largely used in severalsectors of activities. More particularly, they are used to charac-terize the gravimetric effect during the deposit of polymeric film.The impedancemetry method is used to determine the resonancefrequency and quality factor of the quartz oscillator. This doubledetermination makes it possible to improve the sensitivity and es-pecially to detect potential viscoelastic disturbances in polymericfilm process. In the first step, a device which operating at a fun-damental frequency of 9 MHz is used. Results show that thesedevices allow to follow and characterize the polymerization pro-cess of a conducting polymer film (PEDT). In the second step, de-vices can be used to, in particular, follow oligonucleotide (ODN)grafting. Gravimetric and viscoelastic effects of the film were in-vestigated and discussed during the ODN integration onto thepolymer surface. Finally, these studies allow us to identify, inves-tigate and to better understand the gravimetric and viscoelasticprocesses caused by ODN on the film and also will offer the po-tential advantage of real time solution monitoring of nucleic acidshybridization by QCM.


Two-Channel Resonant Formalism Applied to the Scatteringof a Fluid Cylinder in an Elastic MediumPascal Rembert, Hervé Franklin, Jean-Marc ConoirLaboratoire d’Acoustique Ultrasonore et d’Electronique (LAUE),UMR CNRS 6068The problem of acoustic waves interacting with a fluid cylinder in-cluded in an elastic medium at normal incidence is investigated.At first, the two-channel L(ongitudinal)-T(ransversal) scatteringS-matrix is built up, for a given mode n, from the separate prob-lems of the scattering of an incident cylindrical longitudinal waveon the one hand, and the scattering of an incident transversalwave on the other hand. In order to isolate the fluid cylinder reso-nances, an exact factorization of two-channel « soft » backgroundscattering S0 matrix is performed such that

S = S0S(∗) (1)


where S(∗) is the resonant scattering matrix that only contain thefluid column resonances. The eigenvalues of the resonant scat-tering eigenmatrix are found to be equal to 1 and exp(−j2δ

(∗)n )

respectively, where δ(∗)n is the classical resonant eigenphase re-

lated to the fluid cylinder resonances in the nth mode. It clearlydemonstrates that the resonant energy is contained in a singleeigenchannel. The mixing angles α and γ (involved in the rota-tion matrix that allows to diagonalize S(∗)) define the polarizationstates of the fluid resonances in the global S-matrix ; they canbe expressed only as functions of the scattered scalar and vectorpotential coefficients involved in the tangential stress equation.The asymptotic behaviour of the fluid resonance parameters (frequency and width) and the mixing angles are analyzed . Therelation between the global S-matrix eigenvalues and the reso-nant scattering matrix eigenvalues is also provided.


Acoustic properties of a corona discharge sensorVincent Joly, Philippe Béquin, Philippe HerzogLAUMThe creation and the detection of acoustic waves with help ofionised gas is called ionic transduction. This work deals with thesensor aspect in which the ionised gas is obtained with a neg-ative point-to-plane corona system in air at atmospheric condi-tions. This work starts from the phenomena involved in nega-tive corona discharges, to understand how a plane wave inter-acts with the charged particles of the ionised gas to give rise toan electric perturbation of the discharge. An experimental set-up has been designed in order to evaluate the acoustic proper-ties of this ionic sensor. This lets us know what the sensor issensitive for: pressure or velocity and, according to the case, tomeasure its frequency response and its sensibility. In this way, aninvestigation is made of the electric perturbations produced in thedischarges placed in a tube closed at one end and at the otherby a loudspeaker oscillating at near resonant frequencies. Ex-perimental results will be compared with predictions from modelsadapted to each configuration (pressure or velocity).



Field flucuations inside a reverberant cavity with movingscatterersJulien De Rosny, Claire DebeverESPCI - LOAIn this talk, we report a study of transient ultrasonic waves insidea strong reverberant cavity filled with moving scatterers. In sucha system, the scatterers motion induces field fluctuations. In arecent paper, based on a diffusive model, de Rosny et al. (PRL2003) show that the elastic mean free path and the dynamics ofthe scatterers govern the field fluctuations. In this talk we go fur-ther by also taking into account the inelastic (absorbing) part ofthe scattering process. Hence ultrasonic reverberant cavity pro-vides a new and simple tool in order to estimate the inelastic andelastic total cross sections of one or several scatterers. We havesuccessfully applied this technique to spherical (2̃0mm diameter)scatterers made of different materials (steel, gelatine, Ureol, oe).These experiments are performed inside a 1.5 litre reverberantwater tank at 900kHz central working frequency.


Acoustic radiation efficiency of a structure covered by aporous layerCédric Devaux, Nicolas DauchezLAUMPorous materials such as polymer foams are well known assound absorbers [1]. In many applications, they are attached to astructure subjected to vibrations. Considering the structure, theyact as an intermediate layer modifying the coupling conditionswith the acoustic domain. The aim of this study is to investigatehow a porous layer bonded to a vibrating structure may affect itsacoustic radiation. A 1D model has been developed to calculatethe acoustic radiation efficiency of a covered piston in a duct [2].The porous layer is described by an equivalent fluid model orby Biot theory [1]. It is shown that the radiation efficiency is notaffected in the low frequency range. In a mid-frequency range,the Biot model shows an increase related to skeleton resonance.This increase is not be predicted by the equivalent fluid model.At higher frequencies, the radiation efficiency decreases, theequivalent fluid model predicting a slower decrease. Thetendencies given by the Biot model have been confirmed in thecase of two experimental configurations: a piston radiating ina duct, and a clamped plate radiating in an anechoic chamber,both covered by two different porous layers.


[1] Allard J.F., Propagation of sound in porous media - modellingsound absorbing materials, Chapman & Hall, London, 1993[2] Wallace C.E., The Radiation Resistance of a RectangularPanel, J. Ac. Soc. Am. (51), p.946-952, 1972


Characterization of a dipole radiation by Laser Doppler Ve-locimetryGrégory Souchon, Bruno Gazengel, Olivier RichouxLAUMThis work concerns the use of a Laser Doppler Velocimetry (LDV)technique for measuring the acoustic particle velocity in free fieldcondition. The aim of the study is to characterise the radiation ofan acoustic dipole. First, pressure measurements are performedin a anechoic room in order to estimate the dipole moment usedin a radiation model. Pressure measurements are also performedin the LDV experimental room (semi-anechoic room) using thesame experimental protocol. In this case, results highlight thegreat influence of the environment (room and experimental sys-tem acoustic properties), especially at low frequency. In a sec-ond time, acoustic velocity measurements are performed in thesemi-anechoic room using the LDV system and a sound intensityprobe. The study points out two major results : - As shown bythe pressure measurements performed in the preliminary study,velocities deduced from the sound intensity probe and from theradiation model does not agree for low frequency, the room beingnot anechoïc. - The acoustic velocity estimated by means of theLDV bench and by the sound intensity probe agree for mediumfrequency (1 kHz). For low frequency, the acoustic velocity cannot be estimated by means of the LDV system because of thenatural convection that exists in the room. The presented resultsshow that it is possible to estimate the acoustic particle velocityin free field condition with a flow velocity in order of 20 mm/s andacoustic velocity in order of 4 mm/s with a frequency of 1000 Hz.


Measure of the group velocity of an acoustic wave in an one-dimensional latticeStéphane Griffiths, Olivier Richoux, Vincent PagneuxLAUMThe aim of this work is the study and the measure of the groupvelocity of an acoustic wave propagating in a complex medium.This medium is an one- dimensionnal lattice formed by Helmholtzresonators periodicaly connected on a cylindrical tube. This kindof system allows an important scattering illustrated by the ap-pearance of forbidden and allowed bands in the spectral domain.


Experimental and theorical results are presented on perfectlywaveguide lattice showing the presence of band gaps frequencyin which the transmission of sound is forbidden. This propertyis used to show that the group velocity of an acoustical wavecan be more important than sound velocity. A gaussian soundpulse whose frequeny content lies completely with the forbiddentransmission region is used to measure the group velocity. Twosorts of procedures to determine the group velocity are used andcompared: the time difference of the maximum of the pulse andthe time difference for its barycentre before and after the lattice.We show that experimental group velocity can be considerablylarger than the speed of sound: with a lattice composed by thirtyresonators, the group velocity in the first Bragg stopband is mea-sured between 2000 and 3000 m/s.


Attempt to improve the pressure reciprocity calibration ofmicrophonesCécile Guianvarc’H, Jean-Noël Durocher, Michel Bruneau, Anne-Marie BruneauLaboratoire National d’EssaisWhile pressure reciprocity calibration of microphones has beeninvestigated for a long time, especially for a standardisation pur-pose [1] [2], works has been done during the past decades [3][4], which provide tools to improve the modelisation and then toimprove the accuracy of measurements. However, existing mod-els does not fully include viscous and thermal boundary layer ef-fects and involve methods (based on empirical models) to char-acterise microphones parameters which cannot fulfil current re-quirements, preventing us from calibrating accurately the micro-phones in the law and the upon part of the frequency band-width (up to 30 kHz). Thus the focus here is to investigate moredeeply, analytically (even experimentally) the reciprocity calibra-tion method and technique, using first revisited description ofeach element of the reciprocity calibration devices which con-veys significant improvements, and then introducing new toolsin the experimental procedure. Finally, requirements would beaddressed to decrease the uncertainties in the results of cali-brations, thereby supporting the aim of the work. [1] H. Gerber,Acoustic properties of fluid-filled chambers at infrasonic frequen-cies in the absence of convection. Journal of the Acoustical So-ciety of America, 36, pp 1427 - 1434, 1964. [2] IEC 61094-2,1992 : Measurement microphones - Part 2 : Primary methodfor pressure calibration of laboratory standard microphones by


the reciprocity technique. [3] K. Rasmussen, The static pres-sure and temperature coefficients of laboratory standard micro-phones. Metrologia, 36, pp 265 - 273, 1999. [4] K. Rasmussen,Radial wave-motion in cylindrical plane-wave couplers. ActaAcustica, 1 : pp 145 - 151, 1993.


Mapping of fluid pressure fluctuations using a scanningLaser-Doppler interferometerKarl Bendel, André GerlachRobert Bosch GmbH, Corporate Research and Development,FV/FLP AcousticsMapping sound fields can extend the understanding of soundcreation and radiation. For an experimental recording of soundfields, pressure, velocity or intensity values have to be gatheredat many measurement positions with great effort. However, thepresence of the microphones or anemometers may significantlyinfluence the sound field. When investigating aero-acoustic noisesources the sensors may also disturb the flow and additionalnoise might be produced. These disturbances can be avoidedby using Laser-Doppler interferometers. The method is based onthe dependency of the refraction index on the local fluid pressure.The optical path length along the laser beam varying with timeaccording to the pressure variations can be detected by Laser-Doppler interferometry. As a reference signal for the phase ofthe local pressure fluctuations a microphone outside the mea-surement field or the driving voltage of the sound source can beused. The method described here has been introduced e.g. byZipser (DAGA ’01). As an example, the method will be demon-strated for an industrial application, the ultrasonic field of a carparking aid. The radiation and propagation of the ultrasound andits scattering at a car bumper will be presented.


Time Response of a Plate excited by a short duration PointForceDominique Habault, Paul FilippiLMA CNRSThe paper presents a comparison between experimental and nu-merical results obtained in the case of a baffled clamped plate ex-cited by a short duration point force. The plate is a homogeneoussteel plate, placed between two anechoic rooms. The excitationforce is provided by a hammer. The hammer can be equippedwith three types of heads made of rubber, plastic or metal. Thefollowing measurements were taken: excitation force at the headof the hammer, acceleration at one corner of the plate, sound


pressure at two microphones situated at 0.5 and 1.5m from theplate. The theoretical results were computed by a method whichconsists in expressing the plate displacement as a series of theresonance modes of the coupled fluid/plate system. In particular,this method provides a straightforward way to describe the de-creasing behaviour of the sound pressure versus time, due to thefluid/plate coupling. For the excitation force, an analytical modelwas chosen in order to describe as closely as possible the mea-sured force; the same model was used for the three heads, withdifferent values of the parameters. The smoothest curves wereobtained for the rubber and the plastic heads. Comparisons havebeen made for the first 60 ms of the acceleration and pressuresignals. The best agreement between computed and measuredsound pressure has been obtained for the rubber head. Furthercomments will be also made on the comparison between thesenumerical and experimental results, based on perceptive criteria.


Localization of scars in the stadium billiard using reassignedHusimi distributionBenoît Teyssandier, Vincent Pagneux, Laurent SimonLAUMIn this paper, classical ray trajectories and high frequency eigen-functions of a billiard with the shape of a stadium are discussedwith the aid of quantum Poincaré plots. This quantum Poincarésection or phase space distribution is given in terms of theBirkhoff variables (s,cosø), introduced in quantum mechanics.This technical point of view have been studied intensively usingWigner and Husimi distribution functions. In this regard, the cur-rent study presents an effective alternative procedure by combin-ing a novel digital signal processing technique, the reassignedmethod, with the so-called Husimi distribution specialized to thecase of mixed irregular dynamic motion. More than a better lo-calization of scars in phase space, the results are then used todevelop a quantitative understanding of eigenmodes scars pro-duced by resonance on periodic orbits. While each distributionhas given strenghs and weaknesses, the reassigned Husimi dis-tribution appears to be the best choice to characterize scars inbilliards.



Multiple scattering of acoustic waves in porous absorbingmaterialsAroune Duclos, Vincent Tournat, Vincent Pagneux, Denis La-farge, Luc JaouenLAUMMultiple scattering of acoustic waves in porous absorbing me-dia is studied theoretically and experimentally. Porous medialike air-saturated polymer foams with open cells, have a non-trivial frequency-dependent absorption that arises due to viscousand thermal effects at the scale of the rigid frame microstructure.In order to produce multiple scattering at ultrasonic frequencies,mesoscale scatterers are introduced in the porous medium host.The effective wavenumber of such a multi-scale medium shouldtake into account the peculiar absorption at the micro-scale andthe multiple scattering at the meso-scale to describe precisely thepropagation of a coherent acoustic wave. For this purpose, anequivalent fluid model, derived from an homogenization method,is used to model the acoustic propagation in the host porousmedium itself. Then, at the meso-scale, the scattering by the in-clusions is described with a multiple scattering approximation (in-dependent scattering approximation), allowing to obtain the totaleffective wavenumber of the porous medium. After some validat-ing results on the multiple scattering by an array of rigid cylindersin air, experiments on the multiple scattering by rigid cylindersembedded in a porous medium are presented and compared tothe developed multi-scale approach. For the host medium itself,the same multiscale approach provides a convenient mean to ac-count for scattering effects not described by the equivalent fluidmodel.


Numerical Description of the Generation of Modal Waves bya Bounded Acoustic BeamNacera Bedrici, Philippe GatignolLaboratoire Roberval, CNRS, Université de Technologie de Com-piègneThe generation of the (generalized) Rayleigh wave by a boundedacoustic beam has been first shown experimentally by Neubauer.The first numerical approach of the phenomenon goes back toNgoc and Mayer who gave the pressure values of the reflectedfield on the fluid/solid interface. Using a numerical simulationmethod for the description of the acoustice beam, we show thegeneration in plane layered structures of so-called ’modal waves’such as the Rayleigh wave, the Scholte-Stoneley or the Stoneley


wave at the fluid/solid or solid/solid interface, guided waves in afluid layer and finally Lamb waves. In the two-dimensional case,cartographies for the pressure or the stress fields are given ineach medium of the structure, allowing to visualize the generationphenomenon. The generation of the interface waves is observedwhen the beam crosses a first fluid ot solid layer, with a specificincidence angle, before it reaches the relevant interface. Thesetting up of each guided wave, as the incidence angle varies, isalso well understood.


The Origin of the Audio Signal in a Beam of Modulated Ultra-sound in AirVolker Mellert, Bernhard Schwarz-RöhrCarl von Ossietzky Universität OldenburgThe parametric generation of low-frequent sound by means ofmodulated or interfering ultrasound is well-known in underwateracoustics. The non-linearity of the equation of state produces alow-frequent sound beam of the high directivity of the ultrasoundprojector. In recent years similar devices are used to generateaudible sound in air. The so-called ultrasound loudspeakers ra-diate with surprisingly high directivity (”audio spotlight”). Exper-iments indicate that the audio signal in air results not only fromthe non-linear equation of state but fluid boundaries play an im-portant role as well.

We. 8:30 Tivoli 1 Outdoor sound propagation I

On the Influence of Source Height on the Sound Propagationover Flat TerrainEdmund BuchtaInstitut für Lärmschutz DüsseldorfThe influence of the source height must be known to determinethe predicted noise load. The influence of the source heightis well-known in room-acoustics however, without reflecting sur-faces, but the ground effect is not observed in outdoor-acoustics.In order to investigate this effect, a measuring campaign was con-ducted. An impulsive source was triggered at different heightsat 0m, 1m, 2m, 3m and 4m above ground. At distances of 50m,100m, 200m and 400m from the source two microphones at eachdistance measured the impulsive sound at two heights (0m and5m). The measuring results gave no evidence that the receiverlevels at any position depend on the height of the source withone exception, that is the source at the ground yields two dB lessreceiver levels.



On the Height of Burst Gain For Small ArmsKarl-Wilhelm HirschInstitut für Lärmschutz DüsseldorfFor large explosions in air, the so-called ”Height of Burst” gain(HOB) is introduced in respective guidelines to consider the in-fluence of the source height above ground on the acoustical re-ceiver levels in the far field. The technical paper ISO 13474, de-scribing the prediction of receiver levels for muzzle blasts fromlarge weapons, inherited the idea of the HOB correction from theANSI standard S2.20-1983. The HOB formula of the ISO 13474predicts significant corrections up to 7 dB, depending on chargeweight and height of burst. If the prediction schemes for muzzleblasts need to consider the HOB gain for all weapons includingcivil and military small arms, this correction would have a greatinfluence on the noise assessment of shooting noise: The num-ber of relevant emission situations would strongly increase. Andit would force range control to record the aiming position of ashooter for every shot to provide reliable input data for noise pre-dictions. In order to decide whether this effect must be takeninto account for the prediction of sound levels in the vicinity of asmall arms range, a dedicated test was conducted using a chargeweight of 100 g TNT as an adequate sample source. Receiverlevels were recorded at several distances and two directions. Asa conclusion, the analysis of the measuring results falsifies theHOB gain for such small explosions. The paper presents the testlayout and discusses the way of analysis. It concludes that theHOB correction does not apply to small arms.


Simple and multi-reflections using the PE method with acomplementary Kirchhoff approximationFrançois Aballea, Jérôme DefranceCSTBSound impact of road and railway infrastructures are more andmore severely regulated by European laws: acceptable thresh-olds in emission and reception are decreasing. This impliesto develop propagation models able to take many phenomenainto account at the same time (meteorology, uneven ground,impedances discontinuities...). The parabolic equation (PE) isone of the numerical methods used for sound propagation sim-ulation in complex outdoor situations. It neglects backscatter-ing. Even if this assumption is effective in many configurations, itdoes not allow to use PE for studies of acoustic wave propaga-tion between a source and a receiver when an obstacle (rigid


barrier, building) is located just before the source, or just be-hind the receiver. In those cases, energy reflected by obstacleis not negligible and results obtained with PE may be incorrect.This paper aims at presenting a new method able to integratebackscattering in GFPE (Green’s Function Parabolic Equationmethod). In this approach a complementary Kirchhoff approxi-mation is used by setting to zero the sound pressure above thevertical obstacle. Thus, new configuration as the multi-reflectionscan be studied with this new method. In order to point out therole played by backscattering, we first study a barrier located justbehind a source. Then, comparison with BEM (Boundary Ele-ment Method) calculations is presented in the case of a simplereflection in homogeneous and inhomogeneous atmosphere. Amore complex road traffic noise configuration made with two par-allel barriers and meteorological effects is also studied. Resultsshow that the complementary Kirchhoff approach seems to bepromising.


Outdoor sound propagation modelling in complex environ-ments: A new PE code coupled with a micrometeorologicalcodeBertrand Lihoreau, Benoît Gauvreau, Isabelle Calmet, MichelBérengier, Philippe Blanc-BenonLaboratoire Central des Ponts et ChausséesIn complex environments the modelling of outdoor sound propa-gation implies to take into account the mixed influence of groundcharacteristics (topography, obstacles, impedance, etc.) and at-mospheric conditions (refraction and turbulence). We have devel-oped a new PE code coupled with a micrometeorological codein order to calculate the sound propagation above a non flatground in such realistic outdoor situations. Numerical resolu-tion have been developed using the paraxial approximation ofthe wave equation in bidimensionnal configurations with a split-step Padé marching scheme. In our approach the effects of thetopography are modelled using rotated systems of coordinatesin order to treat the ground as a succession of flat domains.Our code can deal with different boundary conditions like theintroduction of impedance jumps or thin screens which lead todiffraction of the acoustic energy. It also includes scattering ef-fects due to atmospheric turbulence through the discrete randomFourier modes technique. The atmospheric turbulence is consid-ered as isotropic, homogeneous, and essentially due to tempera-ture scalar fluctuations. Predicting long-range sound propagationover a non-urban site with complex propagation media requiresthe knowledge of micrometeorological fields in the lower part of


the atmospheric boundary layer. Thus our modelling is coupledwith a dedicated micrometeorological code (SUBMESO) whichsimulates wind and temperature fields over moderately complexterrain with high resolution. Its output data are used as input datafor our PE code through a suited routine.


Ray-Tracing in a 3-D Wind Field for Prediction Purposes ofShooting Noise: Part IKarl-Wilhelm Hirsch, Jürgen ZangersInstitut für Lärmschutz DüsseldorfFor correlation purposes of annoyance due to shooting noise,specific prediction models are available that in particular considerthe long-range propagation necessary to cover the whole rangewhere such blasts are audible. They follow traditional concepts ofnoise prediction relying on long-term average levels, distinguish-ing only between downwind and up wind conditions. The widedistribution of measured receiver levels for shooting sounds atmedium and large distances, however, indicates that the short-time variation in the atmosphere has a dominating influence onthe propagation of sound. It is clear, that these models do not ap-ply to short-time predictions. Two major applications need short-time predictions: Firstly, the daily noise management for shootingranges and training facilities requires a prediction of receiver lev-els for specific, predicted weather conditions. Secondly, any opti-misation of a design for a ”low noise” range needs in advance in-formation on the benefit of an improved layout with respect to thelocal geometry and to a variety of expected weather conditions.The paper reports on a trial to set up a model that considers theacoustical phenomena needed for both tasks. The model relieson 3-D ray propagation in a 3-D wind vector field. Therefore, itallows to study the effect of local changes in the wind field, forinstance of a vertical air flow or of vortices generated over a cornfield or by a wind turbine. Part I of the paper discusses the back-ground, part II explains the basic physical and numerical ideas ofthe approach.


Ray-Tracing in a 3-D Wind Field for Prediction Purposes ofShooting Noise: Part IIJürgen Zangers, Karl-Wilhelm HirschInstitut für Lärmschutz DüsseldorfPart I discusses the need of a short-time, long-range sound prop-agation model for the prediction of shooting noise. In order todevelop a 3-D prediction model to describe the long-range prop-agation of shooting sounds, the implementation of a 3-D wind


vector field is a pre-condition, because in a realistic lower atmo-sphere, vertical air flows and vortices on a medium scale are notan exception that proves the rule of a stratified atmosphere, it isoften a typical state. Therefore, the approach relies on Pierce’sconcept of wave front ray tracing. As a basic idea, the modelpropagates hexahedrons as finite elements (looking like tents) todescribe the transfer and the reception of acoustical energy froma directional spherical source to the receiver. The numerical im-plementation requires sophisticated procedures. (1) Due to theill-conditioned non-linear differential equations, it is necessary togenerate a mesh on the sphere that is fine enough to solve theequations on the propagating wave front accurately. (2) The stepsize increments used for integration are critical for accuracy andcomputation time. (3) In order to maintain spatial resolution forlong-range propagation, a splitting process is required to dividerays into a collection of sub-rays. (4) The reflection at the groundneeds complex numerical concepts to describe the geometry ofthe elements close to the ground. 3-D wind vector and tempera-ture fields are natural features of this model. The paper discussesthe physical and numerical challenge of this approach and high-lights the steps to follow.


Study of the relative influence of some outdoor propagationphenomenaMaud Priour, Eric Premat, Philippe Blanc-Benon, Jérôme De-franceCSTBRegulations concerning traffic noise are becoming more andmore demanding: acceptable noise levels imposed are lower andlower. Today, meteorological effects can no more be neglected,they have to be taken into account in models which predict soundpropagation at long ranges. In order to predict accurately thesound field in outdoor acoustics, the Boundary Element Method(BEM) is a powerful tool, but it can be used, in its classical formu-lation, only for quiescent media. A work is currently undertaken,aiming at including meteorological effects (temperature and windspeed gradients) in the BEM approach. In outdoor sound propa-gation, many phenomena such as absorption, refraction, diffrac-tion can occur and interact in a complex manner in the sametime. In this view, it is of particular interest to investigate if somepropagation phenomena can be separated or have to be consid-ered simultaneously. A study has been carried out on a config-uration with a noise barrier in order to assess a maximum dis-tance under which refraction effects can be neglected comparedto diffraction. In this paper, computational results are given and


the evolution of this maximum distance is represented versus dif-ferent parameters (frequency, barrier height, receiver and sourcepositions, meteorological parameter). Comparison of noise lev-els maps show that the results are encouraging: it seems thatareas where meteorological effects can be neglected comparedto diffraction effects could be enhanced.

We. 13:50 Tivoli 1 Cavitation and sonoluminescence

Particle modeling of strongly collapsing microbubblesThomas Kurz, Daniel Schanz, Burkhard Metten, Werner Lauter-bornDrittes Physikalisches Institut GöttingenMicrobubbles having a rest radius below a few micrometers canbe regarded as mesoscopic systems amenable to direct particlesimulation on a molecular scale. In the final stages of strong col-lapse of such bubbles under ultrasonic or shock wave excitationa highly-excited, rapidly changing inhomogeneous state of thebubble medium emerges. Modeling of its dynamics is an involvedtask due to the interplay of several physical processes, e.g. heatand mass diffusion, phase transition, ionization, light emission,and chemical reactions. A review is given of our recent attemptsto simulate the physical and chemical scenario within collapsingbubbles by means of molecular dynamics simulations with up toseveral million particles. Different driving conditions, bubble com-positions, and thermodynamic and physicochemical mechanismswere implemented and selectively turned on. In this way the rel-ative importance of the included effects can be assessed, as re-gards the maximum temperature and pressure achieved in thebubble, the formation of compression or shock waves, the gener-ation of cavitation luminescence light, and the concentration andoutflow of chemical products.


Boosting Single Bubble SonoLuminescence with an acous-tic pulseJean-Louis ThomasCentre National de la Recherche ScientifiqueSingle bubble sonoluminescence is characterized by a great con-centration of energy conducting to the generation of UV photonwith ultrasound of centimetric wavelength. The estimate of thegas temperature at the end of the bubble collapse has fluctuatedof four orders of magnitude according to the assumptions con-trolling the gas dynamics. These fluctuations mainly come fromthe hypothetical existence of an acoustic shock wave inside thebubble, which would lead to very high temperature at the bubblecore. This work addressees the feasibility of modifying the SBSL


domain of stability to reach this shock wave dynamic in the bubbleinterior. The idea is to add a high frequency pressure pulse to themonochromatic low frequency field used in the now classical set-up. This pressure pulse is generated with eight high frequencytransducers adaptively focused on the bubble and synchronisedwith its low frequency cycle. A transient boosting of sonolumi-nescence can be achieved by applying a negative acoustic pulseduring the expansion stage. This last case results in an increaseof the maximum radius of the bubble. More interesting, a positivepressure pulse impinging on the bubble during its collapse in-duces a brutal acceleration and launches strong pressure wavesinside the bubble. This leads to a flash of much higher intensityand this gain is correlated with the gas pressure heterogeneity.This transient process is not limited by the classical domain ofstability and acoustic pulses of higher amplitude should lead tothe very high temperatures associated with shock wave dynamic.


Determination of the upper boundary in the energy distribu-tion involved in the collapse of sonoluminescing bubblesThierry Lepoint, F. Mullie, Stéphane Labouret, C. Pétrier, D. Keft-ing, Reinhard Geisler, Robert Mettin, Thomas Kurz, WernerLauterbornLaboratoire de Sonochimie et d’Etude de la Cavitation, InstitutMeuriceMultibubble sonoluminescence (MBSL) spectra of95 − 98% H2SO4 solutions containing noble gas consist ofa continuum which extends from ~250 to ~1000 nm. For λ < 250nm, there is no observable emission. With Kr or Xe as thedissolved gas, small-intensity lines are observed in the 700 -950 nm wavelength range. By comparison with appropriatelamps, we attributed them to Kr[4s24p55p1 − 4s24p55s1] andXe[5s25p56p1 − 5s25p56s1] electronic transitions. This meansthat energy levels of 11.3-12.1 eV are populated in the caseof Kr and ~9.9 eV in the case of Xe. When Ar is the dis-solved gas, no Ar lines (which would involve a populating in3s23p54p1 levels characterized by energies of 12.9-13.3 eV)are observed. Given the absence of emission below 250nm, these observations show that the upper boundary in thedistribution of energu released to the intracavity medium uponthe collapse of sonoluminescing bubbles is ~12 eV. Theseobservations enable to understand the reason of the absence ofthe hydrogen ’Balmer’ series in water MBSL. Indeed, transitionsleading to Hα (656.28 nm), Hβ (436.13 nm), Hγ (434.05 nm) andHδ (410.37 nm) lines requires H → H∗ electronic excitationsover a range of 12.10-13.11 eV. Moreover, the absence (or


negligible) emission below 250 nm discards thermal or plasmaorigins for MBSL. The ~12 eV upper boundary in the energydistribution associated with the collapse of sonoluminescingbubbles indicates that MBSL spectra are mainly molecular.


Sonochemical yields of cavitation collapse by molecular dy-namics simulationDaniel Schanz, Thomas Kurz, Werner Lauterborn, Burkhard Met-tenDrittes Physikalisches Institut GöttingenThe collapse of a single acoustically excited bubble is simulatedusing a hard-sphere molecular dynamics model. Initial bubblesize, acoustic driving pressure and bubble composition are var-ied to study the influence of these parameters on the physicalconditions attained during the collpase. Also, modifications ofthe MD model, e.g. by implementation of the variable-soft sphere(VSS) potential, are introduced to assess the model fidelity. In thesimulation, different particle species (e.g. noble gas atoms, wa-ter vapor molecules) and their chemical reactions are taken intoaccount. At the end of the collapse, high temperatures and par-ticle speeds occur because of energy-focusing in the sphericalbubble. At driving conditions typically encountered with single-bubble sonoluminescence, temperatures and pressures are suf-ficiently high to lead to molecular dissociation and sonochemicalreactions, in particular the formation of OH radicals. We investi-gate the sonochemical yield in a number of representative casesand point out that the effect of mixture segregation appears to beimportant to correctly predict the rate at which reaction productsenter the liquid phase.


Optical Cavitation in an Ultrasonic Sound FieldDennis Kröninger, Thomas Kurz, Reinhard Geisler, WernerLauterbornDrittes Physikalisches Institut GöttingenThe dynamics and luminescence of transient bubbles producedby optical breakdown in a standing ultrasonic field are investi-gated experimentally. For this purpose, single laser pulses of 130fs duration and of adjustable energy are focused at the center of awater-filled cuvette insonicated at about 45 kHz. The sound gen-erator and laser electronics are synchronized to be able to gener-ate bubbles at well-defined, adjustable phases of the acoustic cy-cle. The first few oscillations of the bubbles are photographically


recorded to give their radial dynamics and collapse behaviour. Al-ternatively, they are observed by a photo multiplier to detect pos-sible cavitation luminesence. It is found that by the action of theacoustic field, the collapse time and maximum radius can varysignificantly as a function of the initial phase. These parametersalso depend on the acoustic pressure and the laser pulse en-ergy. Luminescence has been detected almost exclusively afterthe first collapse, its intensity also being dependent on the initialphase. The characteristics of cavitation luminescence suggest astrong influence of the sphericity of the generated bubbles. Theexperimentally observed dynamics are compared with numericalcalculations of a spherically symmetric Gilmore model.


Role of the Emergence Delay of the Inertial Cavitation Fieldin the Iodine Release by Ultrasonic Cavitation in ChoppedIrradiation ModeStéphane Labouret, Laurence Deraes, Jacques Frohly, ThierryLepointService de Physique-Electricité, Institut MeuriceThe ultrasonic cavitation is known to give larger effects when pro-duced by pulsed ultrasound mode rather than produced with acontinuous emission. This phenomenon is due to a reconstitu-tion of the population of the chemically active cavitation nuclei bythe partial dissolution of free bubbles between two pulses. Sev-eral of these results have been obtained for irradiation duration inthe minute range and for an ultrasound frequency close to 1 MHz[1,2]. We observe in similar conditions that the inertial cavitationfield occurs with a delay that depends on the chopping frequency.We have also controlled that the presence of the inertial cavita-tion field is necessary to obtain a significant iodine (I2) productionfrom KI solution (Weissler reaction). At last, the variation of thecavitation effect intensities in function of the chopping frequency,which is meet in literature, displays some similarities with the be-haviour of the emergence delay of the inertial cavitation field. Wewill present measurements of iodine production in function of thechopping frequency, of the irradiation duration and of the acous-tic power, taking care to note always the emergence delay of theinertial cavitation field. We will discuss of the possible links be-tween this emergence delay and the effect increase in choppedirradiation mode. Ref : [1] Ciarravino V., Flynn H.G., Miller M.W.:Ultrasound Med. Bio., 7, pp 159-166 (1981). [2] Clarke P.R., HillC.R.: J. Acoust. Soc. Am., 50, pp 649-653 (1970).



On the Classification of Cavitation Bubble StructuresRobert Mettin, Dagmar Krefting, Topi Tervo, Philipp Koch, WernerLauterbornDrittes Physikalisches InstitutIt has recently been recognized that the appearance of acous-tic cavitation can be classified into several prototypes of bub-ble structures. We report on new results and characterizationof such structures. Experimental methods comprise high-speedcinematography and recording of acoustic emissions. Propertiesof different bubble patterns are discussed, in particular with re-spect to ultrasonic cleaning and surface erosion. Furthermore,the controllability of bubble structures by external means is in-vestigated.


Simulation of Cavitation Bubbles in Travelling AcousticWavesPhilipp Koch, Robert Mettin, Werner LauterbornDrittes Physikalisches InstitutA particle model is employed to simulate bubble tracks in a travel-ling acoustic wave. The primary Bjerknes force is rewritten for thegeneral case of spatially varying phase of the pressure, leadingto a force term related to the phase gradient. Other features ofthe particle model include rectified diffusion, bubble merging andsplitting. We compare experimental observations of bubble struc-tures below a sonotrode of large diameter to simulation results.In this experiment, a high contribution of travelling waves is foundat elevated sound intensity, leading to a large acoustic pressureonto the bubbles away from the emitter surface. The observa-tions are reproduced fairly by the model, if certain assumptionson the bubble sources are made.



Experimental Studies concerning Ultrasonic CleaningMarcus Kristen, Annekathrin Kern, Reinhard LerchDepartment FV/PLO, Robert Bosch GmbH StuttgartHigh-intensity ultrasound is nowadays widely used in industrialapplications, including cleaning of precision manufactured me-chanical parts. Increasing demands on the cleanliness of suchparts ask for an improvement in the design and optimization pro-cess of ultrasonic cleaning systems. To get a deeper physi-cal understanding of the interrelations inside the cleaning bath,it is necessary to utilize precise simulation and measurementtools to determine the relevant parameters such as the pressurefield distribution. Due to the high acoustic intensity, cavitationis mostly present. Results from fundamental studies in stand-ing wave fields within tube reactors using different measurementtechniques (hydrophone and laser vibrometer) are presented. Inorder to determine the values of the sound intensity in a standingwave field, we have built up a new type of intensity probe. Theresults of all these measurements are compared with those fromfinite element (FE) simulations as well as with analytical solu-tions. When the acoustic intensity is raised above a certain levelnonlinear wave propagation and cavitation effects have to be con-sidered. Hydrophone measurements and sonoluminescence im-ages are taken to visualize the structure of the cavitation field.These results are compared with FE simulations in which the in-fluence of cavitation is taken into account. Finally, a new methodto soil parts in a consistent way is presented. These soiled partsare exposed to the ultrasound field and the effect of cleaning isdetermined. A correlation between the results of the cleaningtests and the parameters of the ultrasonic field is deduced.


Ultrasonic cavitation in thin liquid layerBertrand Dubus, Alexei Moussatov, Christian GrangerInstitut d’Electronique de Microélectronique et de Nanotecholo-gie, UMR 8520 CNRS, département ISENThe generation of ultrasonic cavitation in a thin liquid layer com-prised between a sonotrode and a hard surface and bounded lat-erally by a gas-liquid interface is investigated. Theoretical analy-sis predicts that a large amplification of the pressure is obtainedwith this configuration. Experiments conducted by driving thelayer with axisymmetrical resonant transducers (20 kHz) showthat ultrasonic cavitation is obtained at very low input intensityand in a broad frequency range. Two types of cavitation arefound depending upon the sonotrode vibrational velocity: at low


velocity, stable bubble structure takes place along the symme-try axis; at high velocity, transient bubble structures constitutedby so-called ’smokers’, are observed. Erosion tests on metallicfoils demonstrate the existence of an intense mechanical activitywhich can be localized by controlling the input intensity. Cavita-tion in thin liquid layers appears to be an attractive approach toscale-up sonoreactors for industrial applications.


Interaction of Bubble Clouds and Solid ObjectsTopi Tervo, Robert Mettin, Dagmar Krefting, Werner LauterbornDrittes Physikalisches InstitutWe present high-speed observations of acoustic cavitation bub-bles near and on solid objects submerged in the liquid. The dy-namics of various bubble structures are revealed in the presenceof the boundaries, and the effect on surface cleaning is inves-tigated. Bubble sizes and density statistics are obtained fromthe recordings. It is known that cleaning and erosion effects aremainly caused by bubbles in direct neighborhood of or in contactwith the object. The number of such active bubbles is estimated.

We. 8:30 Tivoli 2 Auralisation

Evaluation of microphone positions for music and speechrecording by auralisationMarcel Babazadeh, Ingolf BorkPhysikalisch Technische Bundesanstalt, FB 1.6 SchallFor the quality of a music recording the room properties and thepositions of the microphones are crucial. Systematic investiga-tions have been carried out comparing measured and simulatedbinaural sounds at well defined positions relative to the soundsource, a loudspeaker with omnidirectional or normal directivityresp.. Pink noise, sounds of musical instruments and male voicewere used as test signals in two rooms: a concert hall and arecording studio. The well audible differences of the different po-sitions could be related to the calculated room acoustical param-eters according to ISO 3382 as well as to particular recordingconditions (wall reflections). It could also be shown that the cal-culated sounds match the real recordings to a high degree whichenables future experiments based on simulations only.



Virtual Binaural Auralisation of Vehicle Interior SoundsRoland Sottek, Daniel Riemann, Philipp SellerbeckHEAD acoustics GmbHIn order to optimize the quality of vehicle interior sounds alreadyat an early stage of development, two methods called ”BTPA” and”BTPS” (Binaural Transfer Path Analysis and Binaural TransferPath Synthesis) have been developed. Since these methods in-volve the auralisation of the contribution of each individual soundpath, all corresponding transfer functions must be measured sep-arately. The methods distinguish between airborne and structure-borne sound paths. The transmission of airborne and structure-borne sound to the driver’s ears is measured reciprocally usinga recently developed binaural volume velocity transducer on thedriver seat as well as microphones or accelerometers at the noisesource positions. The advantages for taking reciprocal measure-ments of acoustic transfer functions are evident: First, little spaceis required for sensors. Therefore the measurement positionscan be chosen almost without restriction leading to a higher ac-curacy. Second, significant time is saved, since all paths canbe measured simultaneously. The first applications in vehiclesare very promising. Further research projects deal with replacingintricate measurements by simulations using computer models.The goal of these efforts is to divide each transfer path into partialstructures, i.e. if only one component is modified, the simulationonly needs to be performed for the modified substructure ratherthan for the entire transfer path. Simplified models describing thestructure-borne sound transmission in vehicles from engine tochassis can be found with the help of the four-pole-theory. Four-poles are approximated by electromechanical circuits, in order toanalyse the influence of the subsystem on the complete vehiclemodel.


Objective and Subjective Evaluation of the Large SignalLoudspeaker BehaviorWolfgang Klippelklippel GmbHThe results of nonlinear and thermal loudspeaker modeling arethe basis for simulating the transfer behaviour of loudspeakersin real time by using any electrical input signal (test stimulus,music). The model implemented in a DSP provides importantstate information (displacement, current, temperature) and al-lows a decomposition of the sound pressure output into the lin-ear and nonlinear distortion components. This technique com-bines objective loudspeaker analysis with subjective auralisation


used as a new tool in loudspeaker design and basic researchon the perception of loudspeaker distortion. Preliminary resultsof an interactive listening test currently performed on the websitewww.klippel.de/aura are presented and the factors influencing theaudibility of loudspeaker distortion are discussed.


Auralisation of room acoustics - A tool for planning broad-cast production rooms?Sebastian Goossens, Roman StumpnerInstitut für RundfunktechnikBroadcast sound engineers are very critical users of their pro-duction rooms. For an assessment of the acoustical character-istics of rooms being planned you have to make the acousticalcharacteristics audible by simulation. Therefore you need a high-quality-auralization of the sound field at a time when the roomsare still being planned and actually do not exist yet. The consis-tency with the physical conditions is particularly important. Thesound reflections of the walls must be calculated in magnitudeand phase for rooms with a low reverberation time. The soundabsorbers - necessary for adjusting the room acoustics - haveto be calculated according to the theory of sound absorbers andthat is dependent on the angle of the sound incidence. For lowfrequencies the spreading of spherical waves must be taken intoaccount. Special calculation methods for simulation and auraliza-tion have been developed and will be introduced in the lecture.


Auralizing Auditoria in North Portugal: Two case studiesMaria Ribeiro, Ingolf BorkFaculdade de Engenharia da Universidade do Porto(FEUP/CEDEC)This paper deals mainly with auralization performed in two audi-toria: one highly absorbent mainly for cinema presentations butalso used for music concerts (CMM), the other much more reflec-tive, mainly used for musical theatre performances (TECA). Ourmain objectives were to evaluate their sound quality and how thatsound is related to architectural and acoustical properties of thetwo auditoria. First we will present and compare acoustical ob-jective parameters values obtained by in situ measurements andby room acoustic prediction software. Secondly we will comparethe results from analysis of the impulse responses obtained byperforming binaural auralization: a) over measured impulse re-sponses in the real rooms using a real-head technique; b) overcomputer simulated impulse responses using room acoustic pre-diction and auralization software. Finally we will compare the


subjective experience of listening directly to the measured and tothe generated IR and after their convolution with anechoic record-ings obtained from audio libraries. Further, a real sound record-ing with loudspeakers, as sound sources, will also be used. Asa conclusion, we will comment the difficulties experienced and,based on our own and very recent incursion in this area, thereal possibilities to use auralization for detecting some acousti-cal and undesirable phenomena, like flutter echoes and virtualsource displacement and make them audible for architects.


Auralisation of machine structure-borne sound due to rollingbearingsJoão Henrique Diniz GuimarãesInstitute of Technical AcousticsThis work presents the results of the auralisation of machinestructure-borne sound coming from a rolling bearing. Firstly, aphysical model of the contact was created to calculate the loaddistribution during the contact of rough surfaces. This model wasadapted to correspond to the case of rolling bearings and its dy-namic was considered to simulate the actual excitation signal independence to parameters such as rotational velocity, radial loadin bearing and roughness profile of the surfaces. Then, with theuse of previously measured transfer functions from the excitationpoint to a vibration sensor mounted on the machine surface, theresult of these excitations can be auralised for different surfaceconditions of ball and cylindrical rolling bearings. The resultingsignals are then compared with measurements taken with ac-celerometers on the running experimental machine.


Towards an Optimal Sound Insulation by Auralisation andComputational Prediction MethodsKlaus NasshanFraunhofer Institut BauphysikThe audible difference of the sound transmission of differentbuilding parts under a certain excitation noise, e. g. road traffic,does not necessarily correlate to the weighted sound reductionindex. But how can the decision making be supported during thedeveloping process of building parts? Auralisation is the tool ofchoice for giving an impression of both the state and the aim ofthe development. Several software products, which run real-time,allow presentations of arbitrary length and instantaneous switch-ing to another building element or to another sound source. As


a second tool for optimisation of the sound insulation of build-ing elements computer programmes for the prediction of the fre-quency dependent sound insulation are available, in particularthe programme LAYERS written for layered structures. The un-satisfactory trial-and-error procedure, which is still used in thedevelopment of building elements, can be avoided by these pre-diction and auralisation capabilities. Some audible examples ofsound transmission and walking noise will be presented.


Using Auralisation as a Tool for Subjective EvaluationEva Arato-Borsi, Andor T. FurjesAFT ACOUSTICS LtdThe set of room acoustical parameters used for qualification stillneeds to be investigated from the subjective points of view. Ar-ranging comparative experiments is hard and time-consuming,both for the subjects and the researchers. Auralisation can bea tool for supporting these experiments, since room acousticalmodels can be varied and calculated easily. In practice it ishard to find a set of rooms that represent a given architecturalor acoustical tendency (e.g. same shape with different sizes).The paper gives a short overview of the background of the ex-periments, the auralisation system and some results.


Comparisons between a new Binaural Microphone and a tra-ditional Head and Torso SimulatorPoul Ladegaard, Henrik Haslev, Tommy SchackBrüel & KjærIn some cases, Binaural Recording using a conventional Head &Torso Simulator (HATS) is not practical or desirable. Then the useof a Binaural Microphone featuring two miniature microphonespositioned at the entrance to the ear canal is an obvious choice.The first experiment lists the range of measured objective differ-ences in a few Head Related Transfer Functions with the BinauralMicrophone mounted on a small number of test persons. Mea-surements were done both in Free field and Diffuse field. Theresults were very satisfying. In another test set-up, recordingof sounds with a traditional HATS and the Binaural Microphonemounted on a number of test persons were made. After this fol-lowed Paired Comparison preference evaluation of all recordedsounds. Included, as jury members were the test persons par-ticipating in the sound recordings as well as other jurors for latercomparison. A preliminary analysis of the results indicates thatthe bias errors, when comparing recordings from a HATS andthe Binaural Microphone, mounted on different persons are small


and generally acceptable. However, some deviations in the re-sults seem to relate to the size of the head - distance betweenthe ears of the person wearing the Binaural Microphone. Furtherinvestigations regarding this as well as the use of more test per-sons and other test conditions have been used to validate the firstfindings.


Experiments with Spatially Distributed Sound Sources inReal and Virtual EnvironmentsPedro NovoInstitut für Kommunikationsakustik (Web: www.rub.de/ika)Strictly speaking every sound source has a finite dimensionwhich may be approximated as a point source in circumstanceswhere the source-listener distance or the actual dimensions ofthe sound source allow. Point sources constitute an useful ab-straction which is commonly employed in, for example, AuditoryVirtual Environments. However, in circumstances where a pointsource approximation is not valid various point sound sourcesmay be employed. Yet, a set of sound sources, do not necessar-ily evoke a continuous auditory event as was observed for crowdsounds simulated in a virtual environment and in the reproductionof binaural recordings of applause. In fact the auditory eventswere located predominantly to the right and to the left althoughthe sound sources surrounded the listener. These findings haveprompted further experiments, this time in real environments, inorder to investigate if the observed phenomena were due to thenon-individual HRFTs employed in the dummy head and the vir-tual environment cases. These experiments were performed ina reverberant and in an anechoic chamber employing impulsivetests signals. The results obtained confirmed the previous find-ings but only for signals within a particular range of temporal den-sity of impulses. These results as well as possible explanationswill be presented and discussed.

We. 14:50 Tivoli 2 Railway Noise II

T.G.V. disk brake squeal : a dynamic instability ?Xavier Lorang, Quoc Son Nguyen, Florence Foy, Pierre-EtienneGautierSNCF - Direction de la Recherche et de la TechnologieDisc brakes squeal noise of railway rolling stocks is a sourceof discomfort for both passengers on trains and customers instations. New research studies are necessary to understandthis phenomenon. Various investigations show that squeal isa self excited vibration of the brake and that the emitted noiseranges from frequencies of 5000 to 20000 Hz. It has also been


shown that no thermal coupling needs to be considered and thatthe phenomenon is highly increased when the train comes to astop. In this paper, recent results based on a numerical model ofthe T.G.V. brake are presented and compared with running testsdata. The numerical study takes into account the Coulomb Fric-tion Law with a constant friction coefficient which is sufficient todescribe the vibrations of the brake. The chosen method basedon a modal approach allows to highlight flutter instability of thesteady sliding solution of pads on the disc. It is shown that unsta-ble modes are responsible for the evolution of the dynamic solu-tion: from a sliding solution to a more complex solution. Indeed,non-linear vibrations which propagate as waves and are charac-terised by a stick-slip-separation cycle on the contact zone, seemto be responsible for the emitted noise.


Soundscape design in train stations, I: Soundscape functionand identityJulien Tardieu, Patrick Susini, Franck PoissonSNCF - Direction de la Recherche et de la TechnologieThe goal of sound design is to improve the relation between anobject and its user by way of the sounds the object produces. Inorder to achieve this goal, we propose to consider three prob-lems : auditory comfort, function, sound identity. A soundscapeincludes sound sources, sound signals, and the environment inwhich all of the sounds exist. In the case of train stations, variousareas are of interest that can have one or more functions. Audi-tory comfort is well-known and many efficient technical solutionshave been proposed. With regard to the second problem, thequestion is to know whether it is possible to improve the functionof a space by modifying its soundscape. Finally, sound identityconcerns the capacity of listeners to recognize a given sound inall the soundscapes corresponding to the different areas of a trainstation or across all SNCF train stations. We decided to evalu-ate the last two problems (function, sound identity) within existingtrain stations. Thus, two categorization experiments were per-formed with the same sound samples and two different groupsof subjects. For each experiment, the instructions given to thesubjects were different in order to study respectively the percep-tive and the functional representation. Then, a third experimentdetermined whether people can recognize recordings taken fromtrain stations among recordings of different public areas. Thepresent paper will give a definition of soundscape design in trainstations, explain the methodology, and, finally, present the resultsof the experiments on function and sound identity.



Curve Squeal: Noise Monitoring of applied solutionsBernhard MüllerRail Environmental Center, Swiss Federal RailwaysThe Combating Curve Squeal Project is executed by the Inter-national Union of Railways in order to develop tools to reducethe disturbing noise of trains passing curves. In the last yearsan overview of the extent of the noise-problem for railways, atool box with methods and solutions to combat squeal noise anda theoretical model was developed. The workpackage lead bySBB in 2003/2004 is concentrating on noise monitoring of exist-ing solutions against squeal noise. The aim is to get applicablepractical solutions for the railways to reduce squeal noisel. Mea-surements on test-rigs accompany this monitoring. This paperfocuses on the development of the test procedure and first re-sults of the monitoring program are presented.


Noise Emission Measurement campaign for high speed in-teroperability in Europe : the NOEMIE ProjectPascal FodimanAssociation Européenne pour l’Interopérabilité Ferroviaire (AEIF)Environmental noise has known many recent evolutions concern-ing both the needs required by European environmental policy,and the technical capabilities induced by research and standardi-sation work. The main generation mechanism involved has beenproved to be due to rolling noise excitation, through the combina-tion of wheel and rail roughness. From a noise emission policyapproach, the conditions imposed by interoperability for rolling-stock acceptance tests are described within the railway Techni-cal Specification for Interoperability (TSI), which are in favour ofthe definition of a type testing reference track. In that scope theNOEMIE project aims : - To provide a common database of com-parable and reproducible noise emission values of high-speedtrains in Europe, - To contribute to the definition of an adaptedoperated reference track, which performances are adapted to thenoise emission type testing requirements, - To propose and val-idate a common measurement methodology. After a review ofthe needs, scientific constraints, and technical input of such aproject, the measurement campaign results, and their impact onthe railway noise acceptance methodology testing are presented.



Reduction of noise of railway steel bridges with tuned ab-sorbers on railFranck Poisson, Olivier CosteSNCF - Direction de la Recherche et de la TechnologieEven if all railway steel bridges are different, most of them pro-duce more noise than a ballasted track. Located in populatedarea, steel bridges may generate annoyance for the population.Specific noise reduction solutions must be developed. A researchprogram has been started by the French railway company SNCFfor Réseau Ferré de France to deal with this problem. To under-stand phenomena responsible of noise, the vibroacoustic study iscarried out on the whole frequency range from 5Hz to 5000KHz.The sound pressure level rises up around 40 Hz and 500 Hz.In this frequency band, the statistical energy analysis (SEA) ap-proach is used to evaluate the efficiency of each noise reductionsolution. Tuned absorbers seem to provide the same noise re-duction as a sound barrier. Experiment on a test steel bridge arecarried out to confirm this result. The SEA model will be pre-sented in the paper and especially the diagnostic which leads toconclude that the rail is the more important noise source in highfrequency bands. The principle of the tuned absorbers will bedepicted too. The efficiency of this noise reduction solution willbe discussed.


Noise Source characterization on a TGV-Duplex running atup to 350kph by means of a 2D acoustic arrayFédéric Alibert, Fabien Letourneaux, Olivier Coste, Franck Pois-sonSNCF - Agence d’Essai FerroviaireWithin the frame of an acoustic field test campaign organisedby the SNCF on a TGV-Duplex running at up to 350 kph on ahigh speed line in France, some specific measurements werecarried out to localise and characterize the main sources on thetrain which radiate noise in the environment : the implementedtechnique was an acoustic 2D array apparatus combined with abeamforming processing including dedopplerisation effect. An-other objective was also to improve the measurement method it-self, the SNCF 2D ”star shaped” array, as most of the others con-ventional array devices, requiring several configuration of captorsand therefore several train pass-bys to be able to analyse thewhole frequency range of interest (200- 4000Hz). An alternativedevice was then tested at the same time to overcome this draw-back : a 3 by 3 m array support, equipped with a set of 30 captors


irregularly distributed. This paper proposes at first to describeand analyse the acoustic sources localised on the TGV-Duplex,and to give their relative strength as a function of the frequencyand of the train speed. In a second part, the performances of themeasurement method are investigated : thus, a comparison ofresults provided by the 2 array techniques tested is addressed ;some repeatability test and the influence of the post-processingparameters are also examined. Finally, the results confirm thecapability of the acoustic array measurement method to localiseand classify the noise sources on a train at high speed and fur-thermore that improvements of the measurement technique arepossible.


Silent Railway Bridges - A prediction method to optimise thesound emissionDorothée Stiebel, ?? DegenDeutsche Bahn, DB SystemtechnikThe acoustic problems associated with railway bridges have beenwell known for a long time. When a train runs over a bridge, anoise can be heard to the side of and under the bridge. Thisnoise is called ’bridge-hum’. This effect arises from the vibra-tions caused during the passage of the train being transmittedinto the bridge structure via the rails and the track. Vibrations areincited in the components of the bridge and consequently noise isemitted. This so-called ’secondary air-borne noise’ is particularlydistinct in the area of low frequencies. Up till now, the noise prob-lems associated with railway bridges have been dealt with primar-ily empirically and experimentally. In spite of the expenditure thathas been invested in investigations in the last few years, the fa-miliar noise-reducing measures have not been sufficient in manycases and there are hardly any specifications for the constructionof low-noise bridge structures. Particularly in view of the large va-riety of bridge designs, the approach adopted by Deutsche Bahnof an effective and cost-efficient combination of experimental in-vestigations with simulations to produce the low-noise bridge ispresented in the paper.


Railway noise abatement: the implementation in SwitzerlandRudolf SperlichSwiss Federal Office of TransportIn October 2000 the Swiss federal law on railway noise abate-ment was enacted. These noise abatement measures are fi-nanced by a federal fund which was accepted by the Swiss elec-torate in 1998 within a package of railway infrastructure projects.


The general objective is defined by protecting at least 2/3 of theactually annoyed population. The reduction of the noise impactwill be achieved with retrofitting the entire Swiss rolling stockby replacing cast iron blocks with composite blocks until 2009.Noise barriers with a required length of 300 kms will be essen-tial above all along the freight transit lines to protect highly an-noyed inhabitants during the night period. Buildings with residualvalues above the general noise reception limit are entitled to fi-nancial contributions for insulation measures. Further elementswithin the program or as supporting measures are the implemen-tation of an emission ceiling, a low noise bonus on track accesscharges, noise emission limits for new and improved vehicles anda monitoring programme to observe the noise development bycontinuous noise emission measurements until June 2015.


Track specification for noise type test - specification of com-ponents versus functional approachManfred Kalivoda, Monika Bukovnik, Martin JakschpsiA-Consult GmbHPass-by noise type testing of rolling stock requires tight specifi-cations for the test track. There are two main reasons for that.On one hand track noise generation has to be reasonably lowerthan vehicle emission. On the other hand track specifictions haveto guarantee a high reproducability especially for type testes atdifferent sites. Both, the prEN ISO 3095 and the Technical Speci-fications for Interoperability of High Speed Trains (HS-TSI) there-fore include a number of requirements for the test track. They de-scribe the components to be used such as mono-bloc concretesleepers, stiff rail pads and UIC 60 rail profile. This sort of ap-proach is questioned and an alternative approach (called ATSI)has been proposed in the final phase of the HS-TSI adoption.ATSI uses a functional track specification by limiting the spatialvibration decay of the track. The spatial decay rate is a criterionto describe the vibration damping of the track along its longitudi-nal direction expressed in decrease of rail vibration in dB by meterof track. There is a lot of concern that the ATSI approach cannotguarantee a low noise track. The compilation of a big numberof pass-by noise, decay rate and track vibration measurementson different test tracks will be presented here. This data madeus able to show that the TSI and the ATSI specifications are notequivalent. The decay rate limit as it is proposed at the momentis not able to preclude tracks with high noise radiation.



Automated monitoring station for railway noiseMatthias BrechbühlNorsonic Brechbühl AGA railway is a high-capacity and environmentally friendly modeof transport. However, for people living nearby it is an oneroussource of noise. Swiss transport policy is based on the princi-ple of sustainability and is therefore committed to the transfer ofgoods from road to rail transport. This will lead to an increasein rail traffic and hence to increased noise alongside the rail-way lines that could become a growing problem; the Confeder-ation is therefore actively addressing the problem. The FederalCouncil has passed a new Law on noise control measures onSwiss railways along with a Federal Decree on financing of thenecessary noise reduction measures. A consequence of thesenoise control programmes is the monitoring and analysis of rail-way noise. Six permanently installed noise-monitoring stationsundertake this task. These measurement stations are self con-tained and fully automatic. Sensors in the track will detect thepassage of a train and provide information on its speed, transittime, the number of axles as well as the axle spacing. Two micro-phones connected to each station provide noise data to a soundlevel analyser that will compute the relevant acoustic parameterswith high time resolution. The measurement station computerwill correlate the acoustic data with the axle-count information tocomplete a database of rail movements with their resulting en-vironmental noise burden; this data is transferred regularly to acentral station. Each measurement station has a comprehensivealarm and failure location system in order to ensure that down-time is controlled to a minimum.

We. 8:30 Gutenberg Railway noise

Railway Noise Monitoring in SwitzerlandRobert AttingerBundesamt für Umwelt, Wald und Landschaft (BUWAL)The monitoring of railway noise is part of the Swiss railway noiseabatement programme. At six measuring sites on the railway net-work the noise emissions of every train passing by are recorded.For each train, important parameters such as noise emission,speed, length, type of train and number of axles are recorded.The results of the first year of measurement, amounting to morethan half a million trains, are available now. The large sampleallows us to perform reliable statistical evaluations. The mea-surements will continue until 2015. The collected data will allowfor an evaluation of the emission plan 2015 The emission plan


2015 is a prediction of the noise emissions of railways in the year2015 including the running renovation of the rolling stock. It isthe basis for the planning of abatement measures like noise bar-riers and sound insulated windows along existing railway lines.The data gives information about the whole noise emitted by thesystem vehicle-track. In addition the evaluation of the transit ex-posure level (TEL) provides information about the improvementof new and renovated rolling stock in operationg conditions.


Lower railway noise and railway noise valuation by informa-tion system - The German Railway noise exposure cadastreRolf GessnerDeutsche Bahn AG, Bahn - Umwelt - ZentrumDr.-Ing. Rolf Geßner DB AG, Bahn-Umwelt-Zentrum Schall- undErschütterungsschutz Schicklerstrasse 5 - 7 D - 10179 BerlinGermany Abstract Lower railway noise, and Railway noise valua-tion by noise information system - - The German Railway noise -exposure - cadastre Railway noise is created between the rollingwheel and the rail. Freight trains with influence on the environ-mental noise are most important at nighttime (22.00 - 06.00) TheGerman Railway will reduce the railway noise where it is cre-ated. Source related measures could be a smooth rail surface(acoustic grinding) and a smooth wheel surface. The change ofthe brake system is one possible solution to reduce the passbynoise level of freight trains. The noise reduction is in a range of8 to 10 dB(A). The rail surface is very importend for the noisereduction. One measure is rail grinding - in Germany we knowthe ”Besonders überwachtes Gleis” this is rail grinding and sur-face control with the sound measurment coach. In the currentnoise abatement program on existing railway lines, the measuresfor noise reduction are noise barriers, insulating windows and railgrinding. The German Railway Environment Centre has createda noise-exposure-cadastre. It is based on a geographical infor-mation system and includes the whole network of the GermanRailway (37.000 km). It is very important for strategic statementsand the benefit of noise reduction measures. The system givesthe German Railway the basic tool to fulfil the EU - directive re-garding the assessment and management of environment noise.Strategic noise maps and action plans require only slight modifi-cations.



Mitigation of the ventilation noises at the electric locomotiveBR-182Karlheinz Bay, Peter Brandstätt, Norbert RambausekFraunhofer Institut BauphysikElectric locomotives depend on a multiplicity of ventilation sys-tems. The noise of ventilation systems is dominant at standstillin the station. The possibilities of sound power reduction at theinlet and outlet of a cooling tower for the water/oil circuits arepresented in the paper. The modelling of the coupled systemof thermodynamics, fluid dynamics and acoustics is briefly in-spected. Modifications of the components with respect to thetechnical requirements are shown together with measurementsof the original and modified cooling tower, as well as the effectof silencers. In collaboration with different manufacturers, suppli-ers and research establishments, these investigations are part ofthe Joint Research Project ”Silent Trains and Tracks” supportedby the Federal Ministry of Education and Research (BMBF), Ger-many.


Sound radiation from railway tunnel openingsKurt Heutschi, Rene Bayer, Claude FeissEMPA, Swiss Federal Laboratories for Material Testing and Re-searchMore and more often railway tunnel openings can be found in thevicinity of inhabited areas. Whereas for road traffic tunnels it isstandard to make the segment close to the opening from absorb-ing material railway tunnels are usually built without any absorber.For lack of knowledge on the significance of the sound radiationfrom railway tunnel openings this part is usually ignored. For thatreason the Swiss Agency for the Environment, Forests and Land-scape (BUWAL) initiated a research project to quantify the tunneleffect for railway lines. As the ratios of cross sectional areas forrailway tunnels differ strongly from road tunnels the experiencesfrom roads can not be transferred easily to railways. The problemwas tackled by three different methods: theoretical investigationsand calculations, real-life measurements at existing railway tun-nel openings and 1:16 scale-model experiments. Results (tunnelamplification and radiation directivity) are presented for differenttunnel sections, different train types and different conditions ofabsorbing material close to the tunnel opening.



Developing Noise Control Strategies for Entire Railway Net-worksJakob OertliRail Environmental Center, Swiss Federal RailwaysThe EU Environmental Noise Directive requires member states todeliver noise maps to the commission by 2007 and action plansby 2008 for agglomerations as well as for major roads, railwaysand airports. Noise mitigation projects resulting from action plansare usually very expensive and therefore may threaten the eco-nomic viability of the railways in the current harsh competitivetransport market, thus hindering sustainable transport policies.This is particularly important if projects are strongly infrastruc-ture and not rolling stock based. It is therefore of vital interestthat the action plans and the resulting projects are designed inthe most cost-effective way possible. The EU and UIC sponsoredSTAIRRS (Strategies and Tools to Assess and Implement noiseReducing measures for Railway Systems) project recognised thisneed and developed a tool, with which such optimal solutions canbe obtained for entire railway networks. In testing the tool along10’000 km of railway lines in seven European countries, it wasfound that usually a combination of noise abatement measureslead to sufficient protection in a cost-effective manner. Since datacollection is the most expensive part of the analysis, noise map-ping data is ideally collected in such a way that it can be usedfor the calculation of the different scenarios, from which the mostcost-effective action plans are chosen. The paper shows how theSTAIRRS tool is used for this purpose and how cost-effectivenessconsiderations have led to optimal railway noise mitigation strate-gies in Switzerland and have supported noise related decisionmaking in Luxembourg.


The ’Specially Monitored Track’Johannes Onnich, Bernhard Koch”DB AG; DB Systemtechnik, Abteilung Akustik”In efforts to lower the amount of rail traffic noise, it is importantto reduce the sound at the source of its origination. To realizethis, DB Systemtechnik at Deutsche Bahn has developed a pro-cedure by the name of ”Specially Monitored Track” (SMT). Thisprocedure is based on the realisation that the condition of therunning surface of rails plays a significant role in the creation ofrolling noise. By grinding the running surfaces of the rails, any ar-eas of unevenness (known as ”rail corrugations”) are eliminated.The Federal Railway Office (EBA) officially confirmed ”Specially


Monitored Track” in 1998 as a noise reduction system with effec-tively -3 dB(A). Two grinding procedures are currently approvedfor ”Specially Monitored Track” and may be adopted when imple-menting the process. One is a system of rotating grinding discsoperating with a belt grinder and the other is a milling machineoperating with oscillating and static motion rubbing stones. TheSMT concept is based on the periodic acoustic monitoring of therelevant track sections by means of a sound measuring car de-veloped especially for this purpose.


Determination of the source height of a moving rectilineardistribution of point sources with 2 microphones - Applica-tion to tramwaysGuillaume Dutilleux, Aurélien Salvucci, David EcotiereLaboratoire Régional des Ponts et ChausséesEquivalent source height is an important parameter for accuratepredictions of the impact of new transportation infrastructures. Ithas been shown recently that it is possible to obtain in situ thesource height of passenger cars by a method based on the inter-ferences between two microphones. Passenger cars are a rep-resented by a single point source. The present papers showsfirst that the measurement principle can be generalized to a rec-tilinear distribution of point sources. The distribution is supposedto be parallel to a flat homogenegous ground. A supplementaryhypothesis is that the relation between the amplitudes of the dif-ferent sources involved is known. A measurement system basedon this principle is outlined. The underlying uncertainty and theparameter sensitivity of the method is investigated. The methodis applied to experimental data from tramways. For this kind ofvehicules, the obtained equivalent source height appears to belocated very close to the ground, which is coherent with expecta-tions.


Acceptance of Noise Control Measures Along Railway LinesJudith Hauenstein, Valentin Delb, Matthias Burkhardt, Fredy Fis-cher, Tommaso MeloniErnst Basler + Partner AGThe principal purpose of noise control measures is the reductionof harmful or annoying effects of sound. We assume the noisebarriers being accepted if the noise reduction undershoots thevalue that can be expected based on the well-known dose-effectrelationship. A telephone research done in 1999 focused primar-ily on noise along Swiss roads. It showed that the acceptancetowards noise control measures was mainly determined by their


acoustic effectiveness and the remaining noise exposure. Thegoal of a second study was to compare those results with the sit-uation along railway lines. 169 residents have been interviewedin May 2003. As a case example Rheinfelden (20 km east ofBasel) was chosen where noise barriers of two to three metersheight were realised. Furthermore, Eiken, which is situated atthe same railway line, was chosen as a control group with sim-ilar noise emissions but with no barriers. It could be confirmedthat the acceptance of noise control measures is mainly deter-mined by the remaining noise exposure. However, the acousticeffectiveness of a noise barrier has no significant impact on theacceptance. This is probably because of the relatively poor av-erage noise reduction of 5 dB for the buildings adjacent to therailway line. In addition, following the study of 1999 and a Ger-man investigation of road noise control measures, we examinedwhether the fact that there is a noise barrier reduces the sub-jective annoyance. This so-called ”barrier bonus” could not beconfirmed in Rheinfelden. However, a certain tendency is recog-nisable.

We. 14:10 Gutenberg Sound reinforcement & imm. control

Prognose der Schallemissionskenngrößen von Freiluft-BeschallungsanlagenAxel RoyAkustik Bureau DresdenIm Rahmen der Untersuchungen zu einer SächsischenFreizeitlärmstudie wurden aus einer Vielzahl von Messergeb-nissen Prognoseverfahren für emissionsrelevante Kenngrößenvon Freiluftbühnen entwickelt. Als Ausgangsdaten dienen dabeiu.a. die Zuschaueranzahl bzw. die Größe der zu beschallendenFläche oder die maximale Beschallungsentfernung sowie die Artder Darbietung (z.B. Pop oder Klassik). Daraus lässt sich mitvertretbarer Genauigkeit die zu erwartende mittlere Schallleis-tung einer Bühne voraussagen, ohne dass die genaue Konfigura-tion der Beschallungsanlage bekannt ist. Mit Hilfe des ebenfallshergeleiteten mittleren Richtwirkungsmaßes kann dann der zuerwartende Beurteilungspegel an einem bestimmten Immission-sort vorausberechnet werden. Damit erhalten Genehmigungsbe-hörden und Planer im Bereich Immissionsschutz die Möglichkeit,langfristig z.B mögliche Standorte für Freiluftkonzerte zu unter-suchen sowie kritische Situationen zu erkennen und z.B. Maß-nahmen zur Pegelbegrenzung vorzuschreiben. Das Verfahrenwird an Hand konkreter Beispiele von Freiluftkonzerten erläutertund die Prognosewerte werden mit Messergebnissen verglichen.



Interaction and dependencies of total sound power level,sound quality and noise pollution potential in typical multipurpose arenasVolker LoewerIFB consultingMulti Purpose Arenas have become common during the lastyears. These facilities actually serve as multi purpose event lo-cations for huge crowds from a several thousand to 50.000 andmore spectators. The range of events ranks from soccer to in-door motocross, ice hockey, rock music, musicals and even operaevents. Multi purpose arenas have been built as open stadi-ums, semi-open or closed spaces some of them using retractableroofs. The range of events require enormous flexibility of installedsound reinforcement systems and high quality, as well as highpower output systems.Sound system design goals are analysed and discussed usingsamples of existing multi purpose arenas.Examples of typical sound pressure levels and sound quality pa-rameters are presented. It is shown that the total sound powerlevel may not only be a fundamental parameter for noise pollutionpotential, but may as well be used being one of the basic criteriafor evaluating and comparing sound system design quality for in-and outdoor applications.


Sound System Design in Public environments–Sony CenterForum BerlinJakob KraftRahe-Kraft GbRPublic spaces nowadays require optical attractions like video-screens but also an acoustic ’environment’ for large areas. Typ-ical issues in public spaces can be legal immission restrictions,difficult room acoustics, high background noise as well as specificexpectations from clients and architects. The Sony Center Fo-rum Berlin includes appartments only 26m from the main speakerwith immissions restricted to 60 dB(A), 14.000 m2 of glass sur-face, approx. 6 sec. reverb, a constant background noise of 60-62dB(A) and a client expecting not to see any speakers, but stillgetting excellent audio performance everyplace. Clearly, an in-tegrated approach combining loudspeaker choice and placementwith time-controlled signal processing was clearly required dueto immission restrictions. The project showed also that simula-tion and auralization (CATT-Acoustic) is a necessity to find thebest technical solution but also as a psychological measure to


show the client what is possible. The final technical solution us-ing beam-steered Duran Intellivox columns, securing level limitat-ing with password-protected DSP-Mainframe programming, sig-nal distribution over Cobranet, loudspeaker measurements aswell as architectural solutions making the system ’invisible’ arefurthermore discussed.


Optical Linear Position Measurements of the Speaker Mem-brane Displacement - a New, Cheap and Easy Way to Char-acterize the Speaker Behavior with High AccuracyWolfgang GeigerUniversitätManufacturers of speakers characterize the properties of chas-sis with the Thiele-Small parameters, which are calculated fromthe electrical impedance. The influence of the mechanical pa-rameters is largest at the mechanical fundamental resonanceof the membrane displacement. In additional there are natu-ral resonances of the membrane that influence the quality ofthe speaker at higher frequencies. All mechanical resonancesof the speaker membrane oscillations are detected as electricalimpedance peaks, but at higher frequencies the mechanical nat-ural vibrations of the speaker membrane are concealed by eddycurrent effects and the speaker voice coil impedance. Therefore,it is difficult to calculate the mechanical displacement from theelectrical impedance at higher frequencies, which is fundamen-tal for the sound pressure propagations. Until today most devel-opers measure only the mechanical resonance of the speakerto characterize all speaker properties. When a Position Sensi-tive Detector is used, it is possible to measure the real displace-ment with high linearity, a large dynamic range and a signal tonoise ratio up to 90 dB even at high frequencies are obtained.The electrical impedance can be calculated from the voice coildisplacement transfer function with the lumped element model.The comparison of the calculated data with the measured electri-cal impedance shows an excellent correspondence. The soundpressure can be predicted from the mechanical displacementof the speaker membrane with a simplified lumped rigid pistonmodel. The linearity of the measurement system makes it possi-ble to control the speaker membrane displacement in a real timeclosed loop system



Calculation of sound pressure distribution and relevant val-ues for immission control with computer simulation at theexample of a large sports stadiumAnselm GoertzAudio & Acoustics ConsultingIn locations and rooms for public events today’s standards forsound reinforcement and PA systems are very sophisticated. Notonly a certain speech intelligibility is demanded, there are alsostrict limits for immission control. By taking a large sports stadiumas an example, different design concepts of the PA system willbe explained. This covers the calculation of sound distributionincluding audience areas and surfaces relevant for immission.


Immission Protection in Spite of High Useful LevelsWolfgang Ahnert, Benjamin JägerADA Acoustic Design AhnertThis contribution explains how acoustical quality criteria for astationary stadium sound reinforcement system were elaboratedwith particular regard to minimizing immission to neighboringareas, and how forthcoming concepts from bidding firms wereevaluated. Thanks to the inclusion of the results obtainedby sound-reinforcement computer simulation (EASE) in thecalculated immission prediction it was possible to assess varioussound-reinforcement concepts with regard to the sound quality tobe expected within the stadium, but also in respect of immissionavoidance.

The object of these investigations was the Berlin Olympias-tadion, which is presently undergoing complete refurbishing,and partial redevelopment. During future utilization of thestadium, even with the partial roofing closed, clearly audiblenoise immissions will have to be reckoned with for the adjacentliving quarters consisting of detached and multifamily houses.The aim consisted in minimizing these immissions at least as faras can be achived by technical means.



Controlled illumination by DDS-driven (cardioid) loud-speaker arraysEvert StartDuran Audio BVDuring the last decade, digitally controlled loudspeaker arrays(based on the AXYS R© DDC concept) have proven to be an es-sential tool for the improvement of the sound (re)production inlarge, acoustically difficult spaces, like (semi open) stadiums,churches and passenger terminals.The next step in the ongoing development of digitally controlledloudspeaker arrays is the introduction of Digital Directivity Syn-thesis (DDS). Now, the radiation pattern of (scalable) digital loud-speaker arrays can be fully customised and controlled by soft-ware and can be predicted accurately in the far field as well as inthe near field.In contrast to the conventional approach of clustering loud-speaker systems with a given directivity to achieve a ”hopefully”desired result, the DDS software calculates optimum driving filterfor each channel in an array starting from the desired ’illumina-tion’ of the audience area. In addition, not only can DDS definethe area(s) specified to be covered, but it can actually define thearea(s) requiring no coverage.Recently, a DDS-controlled cardioid bass array has been evalu-ated. This array combines a strong vertical directional behaviourwith a high front-to-back ratio, yielding many acoustic benefitsboth indoors and outdoors.After a short overview of the theoretic principles, this paperwill address the practical design and optimisation aspects ofthese (cardioid) loudspeaker arrays. The flexibility of the DDS-technology will be illustrated by several examples.


Environmental Noise Guidelines and Sound Management forUK ConcertsJim GriffithsDirector of AcousticsThe UK has seen a steady increase in the demand for stagingconcerts both inside purpose built arenas to major rock concertsheld outside on green field sites. This has focussed the attentionto the potential environmental noise impact which is a critical is-sue in respect of obtaining a public entertainment licence beforethe event can proceed.This paper discusses the research leading to the current noiseguidelines adopted for the majority of concerts in the UK and


highlights the sound management control procedures that havebeen successfully adopted at many musical events for over 15years. Engineering measures are also discussed in relation tothe design of new or refurbished venues.


A Test Procedure for Sound Level Limiters in ToysThomas FedtkePhysikalisch Technische Bundesanstalt, FB 1.6 SchallAccording to the standard DIN-EN 71:1998 on safety of toys thesound pressure level of toys which were ’obviously designed forgenerating sound’ has to be limited in order to protect the hearingof the users - the children. This standard specifies level limits forfree-field measurements of the sound immission for toys whichare designed to be used as a unit close to the ear as well as levellimits for the sound immission at the eardrum for toys which areequipped with earphones. If the acoustic output signal of the toyis generated by means of built-in program material, the maximumoutput level can be measured with test signals while the toy isworking with full-on gain. If, however, the output signal dependson an acoustic input, eg a microphone, the performance of thelevel limitation has to be tested by suitable acoustic input signalsand input levels. A test procedure for toys with an acoustic inputwill be described in this paper.


Broadband compact absorbers for anechoic liningsHelmut Fuchs, Xueqin Zha, Gerhard BabukeFraunhofer Institut BauphysikFreefield rooms are normally equipped with voluminous porousor fibrous wedges the depth of which corresponds to a quar-ter of a wave length of the lowest frequency to be measured.When such passive absorbers are intelli-gently combined with re-active/resonant panel absorbers, anechoic linings be-come pos-sible, which may save valuable space and provide a smooth andre-sistive surface. When measurements are to be performed inthird-octave bands, down to 50 Hz, a lining thickness of 250 mmis required. For narrow-band analyses down to 100 Hz the sur-face facing the source must be corrugated in a specific mannerincreasing the total thickness to 620 mm. For aeroacoustic windtunnels and a large number of test beds at six automobile manu-facturers and several component suppliers have been equippedwith the new anechoic linings with excellent results.



Acoustical transparency of perforated panels with fabric lin-ingsMichael Leistner, Horst DrotleffFraunhofer Institut BauphysikIn interior works perforated panels are occasionally used to coverup sound ab-sorbers mounted behind them. In order to create avisually smooth surface, now and then a thin layer of cloth orfleece is applied to the side facing the room. There are alsocases, in which paint is additionally sprayed on top of that layer.The influence of these steps on the sound transmission at normalsound incidence was investigated with some unexpected results.

We. 8:30 Kleber Numerical methods in acoustics II

Temporal Formulation in the Wave Number Domain of For-ward Propagation of Time Evolving Acoustic Pressure FieldsVincent Grulier, Jean-Hugh Thomas, Jean-Claude Pascal, Jean-Christophe Le RouxLAUMThe wavenumber method using the FFT algorithm has proven tobe a more efficient tool than the Rayleigh integral method for cal-culating harmonic acoustic fields from planar radiators (Williams,Maynard). However, this method is not adapted when consider-ing non-harmonic acoustic fields. Therefore the aim of this workis to provide a relevant reconstruction of non-stationary acous-tic fields using a time domain impulse response formulation ofthe problem in the wavenumber domain. This formulation, toour knowledge first given by Forbes and Stepanishen, allowsa real-time prediction of the acoustic wave propagation in thenear-field of vibrating structure or in waveguide for applicationsin active control. First the acoustic propagation in the wave num-ber domain described by the temporal wave equation in planegeometry is considered. A two-dimensional Fourier transformis applied to this equation that leads to a differential equationwritten in a Laplace formalism. The resolution of this equationgives the expression of an impulse response that, convolved witheach component of the time-dependant wavenumber spectrum ina mesurement plane, yields the wavenumber spectrum in a for-ward plane. Then the two-dimensional inverse Fourier transformin space domain provides the instantaneous spatial pressure inthe forward plane. Some explanations to reach the formulationare given in the paper. Numerical simulations are also reportedto confirm the validity of this formulation. These simulations dealwith sources composed of monopoles and more complex planarradiators whose sound emission fluctuates in time.



A journey of Sound Radiation, from the Baffled Plate to theInfinitely Long Cylinder SegmentBerndt Zeitler, Michael MöserInstitut für Technische Akustik , Technische Universität BerlinThe characteristics of sound radiation of the baffled plate bearingmodal velocity distribution will be introduced shortly. Following,the analytically derived radiation characteristics of an infinitelylong cylinder possessing the same modal velocity will be pre-sented. It was chosen as a stepping-stone between the baffledplate, and the infinitely long cylinder segment; with infinite radiusit possess the same radiation characteristics as the baffled plate.By shortening the radius the influence of curvature and diffractionarises, which also occurs for the case of the infinitely long cylin-der segment, which was solved with semi-analytical methods. Fi-nally, the radiation characteristics of all cases will be compared,whereby some of the results are presented by particle anima-tions.


Synthèse Modale pour les problèmes poroélastiquesOlivier Dazel, Franck Sgard, Claude-Henri LamarqueENTPE-DGCB-LASHPorous material involves interesting properties of dissipation ofmechanical energy. That is the reason why they are commolyused in many fields of engineering. Nevertheless, the modellingof such components at the macroscopic scale involves constitu-tive and inertial coefficients which are complex and with a fre-quency dependency. This particularity prevents the applicationof classical modal techniques to predict the dynamical behaviourof multilayered structures involving porous materials. Recently,the authors have developped a technique based on the notion ofcomplex modes. By extending the original Duncan transforma-tion, it has been possible to obtain generalized complex modesenable that account for internal coupling and dissipation. Thistechnique has been shown efficient in the case of monodimen-sionnal and tridimensional single porous structures. In this pre-sentation , the case of multilayered structures is considered andthe aim is to introduice component mode synthesis techniquesfor generalized complex modes. We mainly focus on the applica-tion of free face interface techniques as Craig and Chang CMSmethod. The definition of inertia relief generalized complex modeand residual generalized complex modes is undertaken. It isthen possible to procced to an optimal correction of the boundarycondtions. A global basis of the whole structure is then built by


considering the modal families of each substructure taken sepa-rately. Numerical applications are then shown and various casesare considered. First of all, the coupling of an elastic plate anda porous media, then, the coupling of a porous media and anacoustic cavity and finally the case of coupling of two porous me-dia.


Simulation and measurement of pulsed ultrasonic wavepropagation in viscous fluid exhibiting frequency power lawattenuationLudwig Bahr, Manfred Kaltenbacher, Barbara Kaltenbacher,Reinhard LerchDepartment of Sensor Technology, Friedrich Alexander Univer-sity Erlangen-NurembergMeasurements of acoustic attenuation in tissue reveal, that at-tenuation increases with increasing frequency according to α =α0|ω|

y, where α0 is a scalar constant and y is a non integer ex-ponent ranging from 1 to 2. Classical lossy time domain waveequations exist only for the restricted cases of y = 0 and y = 2.We will present a time domain model, which is capable of numer-ically simulating pulsed pressure waves propagating through me-dia, whose attenuation obeys a frequency power law. To ensuresystem causality, phase dispersion has to be included accordingto Kramers-Kronig relations. Because of the interdependence ofattenuation and phase shift, the two terms describing each phe-nomenon can be combined to a single factor. The attenuationand dispersion term is approximated by a fractional derivative inthe time domain. Simulation results are verified by measuringattenuation and phase spectra of excitation pulse signals afterpassing through a tissue phantom. The phantom is immersed ina water tank of a ultrasonic screening system. We compare thecollected data with the predictions of the underlying theoreticaldamping model.


Quadratic Time-Frequency Representations For SignalsPassing Through Dispersive SystemsJerome Bernard, Silvio Montresor, Jean-Hugh Thomas, ClaudeDepollierLAUMThe aim of this work is to study the propagation of an acousticwave in porous media using quadratic time-frequency represen-tations (QTFR), for example the Bertrand distribution. Becauseof the dispersive characteristic of such a system, the wave veloc-ity in the porous structure is a complex function of the frequency,


i. e., the energy of the signal carried by each frequency has isown velocity. So, a sample of porous medium is excited by anultrasonic pulse, and the QTFR of the output signal is observedto evaluate the group delay law, function of the frequency, andthen the parameters of the material. The relevance of such signalprocessing tools is their capacity to concentrate the energy of asignal in a two-dimensions plane (time-frequency, time-scale,...)along his group delay law. In the case of propagation in porousmedia, the group delay law is compared to a power law in thetime-frequency plane. Finally, the properties of the Power Classof QTFR are used. This class of representations allows to gen-erate a large number of QTFR and each of them matches withone adapted power law in terms of lisibility and the concentra-tion of energy in the time-frequency plane. Hence, to choose themost relevant representation, concentration measurement toolsas Renyi entropy are used. Here, the situation where a signalpasses through a dispersive system which includes a power lawgroup delay to the signals is considered. So, a QTFR which lo-calizes efficiently this kind of signals is needed as well as theWigner-Ville QTFR localizes the linear chirp signal.


Uncertainties and Errors caused by the Use of Noise Predic-tion SoftwareWolfgang ProbstAccon GmbGNoise levels in the vicinity of planned sound radiating facilitiesare generally calculated with software programs. With such aprogram it is possible to evaluate the uncertainty of the result-ing sound pressure level caused by uncertainties of the assumedemission levels of sources. This method has been presented atDAGA 2002 and is in the meantime widely used by consultantsand environmental agencies. It supports the GUM-approach instandardization and helps to receive results with a given confi-dence interval. Uncertainties caused by the use of algorithmsdeviating from standardized procedures can be minimized by us-ing quality ensured software. With the new draft of DIN 45687test problems and self declaration of software producers help thepotential user to evaluate the correctness of software programsand to rank them with respect to his requirements. But there arealso errors that may be caused because the software architec-ture and philosophy is not completely understood. Methods arepresented allowing to detect and to avoid these errors.



Adaptive time-frequency representation for sound analysisand processingFlorent Jaillet, Bruno TorrésaniGenesisReadability and interpretability of time-frequency representationsmay highly depend upon prior choices, such as the type of rep-resentation, an analysis window, or a smoothing procedure. Inthe context of sound processing and particularly for componentextraction or elimination, it is possible to optimise such choices toachieve the best results. We propose a framework for automaticadaptation of the analysis parameters to the signal. This adapta-tion relies on the optimisation of the sparsity of the representationand will be described in the case of the short-time Fourier trans-form. Two different settings are proposed : Supervised adapta-tion The user selects a time-frequency region of interest and thechosen representation is that one which optimises a given spar-sity criterion for the components in the selected region. Differentcriteria may be used, which are studied theoretically as well asnumerically. Unsupervised adaptation The time-frequency planeis divided into several regions and in each region, the sparsestrepresentation in a given set of possible representation is cho-sen. In particular using only two short-time Fourier transformscomputed with two different sizes of window, a ’wide’ one and a’narrow’ one, we show that the algorithm provide a good tool toseparate and represent the transient part of the sound, which isbest represented using the ’narrow’ window, and the tonal part,which is best represented using ’wide’ window. Examples on realsounds will be presented to show the interest of the proposedmethod.

We. 13:50 Kleber Audiology

Evidence for positive training effects of the acoustical envi-ronment on the auditory thresholdGerald Fleischer, Reinhard MuellerAuditory Research, University of GiessenFor nearly a decade, our team collected data on the auditoryperformance and the acoustical environment of roughly ten thou-sand persons. Using special analytical procedures this data baseis being analyzed in different ways. One approach is to exam-ine - and compare - the hearing capability of entire groups, asdetermined by pure-tone audiometry up to 16 kHz. Males andfemales are studied separately, and every group is seprarated byprogram in two sub-groups: persons with good hearing and per-sons with auditory damage. Both of these sub-groups are then


examined further. Among the groups examined are college stu-dents, fans of discos, orchestra musicians, office personnel, uni-versity students, audio engineers, airline pilots, military helicopterpilots, military recruits, dentists, construction workers, avoiders ofdiscos, Tibetian monks, Tibetian nomads, Chinese from remotemountain valleys, Chinese from metropolitan areas, and others.Comparing the auditory performance of these groups made itpossible to work out a ranking. The best-hearing groups are allworking in loud environments, while people not exposed to noise- e.g. nomads - do not hear well at all. While excessive noisedamages the ear, an extended low level of exposure to sound isapparently not good either. It is being concluded that the audi-tory system needs training to fully develop its capacity. Evidencewill be presented to show the training effects and to indicate whatappears to have positive effects on the auditory theshold. Thesetrained ears are ageing more slowly than normal.


Evidence for different susceptibility to auditory damage be-tween men and womenGerald Fleischer, Reinhard MuellerAuditory Research, University of GiessenFor ten years now, our group works on the relation between expo-sure to sound and auditory performance. Primarily we use pure-tone audiometry up to 16 kHz to determine the sense of hearing.In order to get an overview, we are examining and comparingentire groups of persons, such as office workers, music teach-ers, military jet pilots, Chinese city dwellers, etc. Using a specialanalytical procedure the auditory performance is determined andthe results are compared among the various groups. Examiningthe data of a group by program, the first step is to separate per-sons with good hearing from those with auditory damage. Fur-ther analysis involves the entire group, but also - separately - thesub-groups of the good-hearing persons, and those with auditorydamage. Men and women are, of course, examined separately.Looking at the results of the various groups showed a surprisingeffect. Comparing men with auditory damage to women with au-ditory damage - of the same groups - showes that women havemore low-frequency damage than men, but less high-frequencydamage. In groups with larger numbers of such persons, theeffect is statistically significant, over the entire frequency rangeanalysed. It is apparent among very different groups - from Chi-nese nomads, and Chinese city dwellers to European orches-tra musicians and German college students, university students,


amateur musicians, and others. This widespread occurrence in-dicates that differences in susceptibility may be responsible, atleast in part.


Improved venting systems for hearing aid applicationsTorsten Niederdränk, Harald KlemenzSiemens Audiologische Technik GmbHHearing systems can be positioned in or behind the ear. In thelatter case the acoustic signal propagates through an acoustictubing and the ear mould into the ear canal. In both cases theear canal is closed to keep the sound signals inside the limitedrest volume. This way the acoustic stability of feedback is im-proved. In real applications the ear canal cannot completely beclosed. Reasons are that a closed volume with a certain degreeof humidity might provide skin irritations due to fungus or bacterialgrowth. Additionally the occlusion effect appears, which of coursedoes not support the comfort of hearing. To take care of theseissues venting systems are applied connecting the rest volumeof the ear canal with the outer environment. The positive effectsof these vents to improve the venting of the ear canal has a neg-ative side effect: the acoustic leakage allows a certain amount ofsound energy to escape the ear volume and to propagate backto the microphone. Thus a feedback loop is closed. This con-tribution reports on venting systems which provide a consider-ably reduced sound radiation to the outer space. While keepingthe venting effects constant the acoustic radiation of the vent-ing canal is reduced. By using acoustic filters the propagationthrough the ventholes can be influenced in order to achieve aconsiderable reduction of the feedback sensitivity in the criticalmid and high frequency range.


Bone Conduction effecting the Peripheral Hearing OrganHenning Taschke, Herbert HuddeInstitut für Kommunikationsakustik (Web: www.rub.de/ika)In order to analyse the components of bone conduction a finite el-ement model of the human head was developed. The model pre-sented here is a revised version of a previous model (Taschke,Daga ’02) whereby it now confirms to in vivo measurements ofreal heads. Furthermore the model has been extended by amodel of the whole peripheral hearing organ. Due to the largenumber of degrees of freedom, the model had to be sub-dividedinto three parts: the head, the temporal bone, and a cuboid sec-tion including the inner ear and its bony shell. The calculations ofthe three parts had to be made in succession for each different


type of excitation. In this dividing process, care was taken so asto maintain the correct pattern of vibration at the interface areas.The model allows us to investigate the mechanisms of bone con-duction with regard to their characteristic patterns of vibration:Firstly, the vibrations of the tissue enclosing the hearing organwere examined in order to assess whether the tissue is being de-formed or driven as a whole. Secondly, the changes in air pres-sure within the outer and the middle ear, the inertial movement ofthe ossicular chain, and the vibrations of the basilar membrane inresponse to the excitation of the surrounding tissue were studied.The significant findings with regard to the assessed componentsand their underlying mechanisms will be presented.


Modelling the Dynamic Behaviour of the Human Middle EarUsing the Finite-Element MethodYvonne Curdes, Herbert Hudde, Henning TaschkeInstitut für Kommunikationsakustik (Web: www.rub.de/ika)In the talk a finite-element model of the human middle ear will bepresented. This model is based on the results and properties ofa three-dimensional circuit-model of the middle ear from Weis-tenhöfer which is a further development of the one-dimensionalmodel from Hudde and Engel. In contrast to such mathematicalmethods, the application of the finite-element method enablesthe representation of the anatomy of the middle ear. Further-more it offers a wider field of application like, e.g. static analy-ses. A geometric model of the middle ear was constructed in acomputer-aided design environment, using tomograms of tempo-ral bones and silhouettes from ossicles. The model is embed-ded in an existing model of the outer and inner ear developedby Taschke. It consists of the tympanic membrane, the ossicularchain including joints, ligaments (anterior malleal ligament, pos-terior incudal ligament, and annular ligament), tendons (tensortympani tendon and stapedial tendon), and the tympanic cavity.The unknown mechanical parameters of the components of themiddle ear were mainly determined from the geometry depen-dant properties of the three-dimensional circuit model. For thispurpose special, self-programmable elements were used for thejoints and the anterior malleal and posterior incudal ligament. Toconfirm the validity of the model, the motion of the ossicles ob-tained with this model was compared and adjusted to the resultsof the circuit models and measurement data. The developmentof the model and the simulation results of the dynamic behaviourof the middle ear will be presented and discussed.



How do Head-Related Transfer Functions of Children dependon Growth?Janina FelsInstitute of Technical AcousticsIn many standards for development and measurement of hear-ing aids (for example DIN EN 60 118) an artificial head is used.This artificial head (KEMAR), however, is based on anthropomet-rical data of adult heads. Head-related transfer functions (HRTF)of children differ from adult ones. Consequently, there are stilluncertainties in the development of dummy heads and properhearing aids for children. On the DAGA’03 a system has beenintroduced which makes possible to obtain the HRTF even forvery young children with the use of a photogrammetrical systemand the calculation of the HRTF with BEM out of CAD-Models.Very first results showed that there is a big difference betweenHRTFs of infants and of adults. Even a scaled adult head yieldsbig differences in the HRTF in comparison to an infant or child.The geometrical data needed for the CAD-Models have been op-timised for children producing a database that allows statisticalanalysis of different groups of ages. Hence, corresponding headscan be created and computed. The results will be presented anddiscussed.

We. 16:30 Kleber Medical acoustics I

Ultrasonic wave propagation in human cancellous bone: Ap-plication of Biot theoryZine El Abiddine Fellah, Sylvain Berger, Walter Lauriks, ClaudeDepollier, Jean Yves ChapelonNational Institute of Health and Medical Research, INSERM Unit556Ultrasonic wave propagation in human cancellous bone is con-sidered. Reflection and transmission coefficients are derived fora slab of porous material having an elastic frame using Biot’stheory modified by the Johnson et al model for viscous and in-ertial exchanges between fluid and structure. The sensitivity ofthe Biot-Johnson parameters is studied showing their effects onphase velocity and attenuation of the fast and slow waves. Ex-perimental results for waves transmitted and reflected by humancancellous bone samples are given and compared with theoreti-cal predictions.



Fragmentation Mechanisms of Kidney Stones in Shock WaveLithotripsy can be Detected with MicroCT X-ray ImagingRobin Cleveland, Javier Van CauwelaertDept. of Aerospace and Mechanical Engineering, Boston Univer-sityMicro computed tomography (CT) imaging was used to follow theprogressive development of cracks in artificial and human kidneystones. The artificial stones were made from U30 cement witha cylindrical shape (6.5 mm diameter and 8.5 mm long). Thestones were held within a polypropylene vial in one of three orien-tations: vertical, horizontal and angled at 45 degrees. The stoneswere treated with either an electromagnetic or an electrohydrauliclithotripter and the initiation and growth of cracks was observedusing microCT. The images showed that the dominant mecha-nism of failure was very sensitive to orientation of the stones withspall, cavitation and splitting mechanisms observed. Similar ex-periments were carried out on human stones of various types.Stones with homogeneous interiors broke with classic spall andsqueezing like cracks. Natural stones with a complex layeredstructure appeared to initially lose their outer layers by a cavi-tation mediated process before the core fractured by spall. Ourexperiments indicate that most of the proposed mechanisms forstone fragmentation are present in shock wave lithotripsy. Varia-tions in stone size, geometry and orientation appear to play a dra-matic role in determining which mechanism dominates the frag-mentation process. We conclude that there is no one dominantfragmentation mechanism in lithotripsy but rather multiple mech-anisms combine to produce stone comminution. [Work supportedby the Whitaker Foundation].


Focal Pressure Variations in Shock Wave Therapies Causedby Cavitation BubblesMarko Liebler, Thomas Dreyer, Rainer RiedlingerInstitut fuer Hoechstfrequenztechnik und Elektronik / Akustik,Universitaet KarlsruheFor medical applications of pressure pulses in extracorporealshock wave therapies different generator types (electrohydraulic,electromagnetic, piezoelectric) are used. Unlike electrohydraulicsources, electromagnetic and piezoelectric transducers are char-acterised by a high reproducibility of the pressure pulse wave-form. But even for these sources pressure measurements with


a fiber optic probe hydrofone show significant variations in pres-sure waveforms after the first tensile phase of the wave. It is sup-posed that these quasi statistical changes are caused by cavita-tion effects. Numerical and experimental investigations are pre-sented which support this hypothesis. The numerical model usedis based on a two-phase continuum approach for bubbly liquidsand combines nonlinear ultrasound propagation with cavitationbubble activity. The Gilmore equation is applied to calculate thebubble dynamics. Simulation results with different bubble densi-ties demonstrate that the first positive pressure part of the shockwave is not affected by the bubbles. Increasing the gas contentthe tensile part gets shorter and is followed by augmented pres-sure oscillations. Measurements on two focusing piezoelectrictransducers using different gas contents confirm the simulations.Calculations as well as experiments demonstrate that the activ-ity of cavitation bubbles induced by the shock wave itself causessignificant changes in the decaying part of the pressure signal.


Frequency effect on the cell detachment by ultrasoundLudovic Peyre, Dorothée Callens, Annie Lefebvre, EdouardRadziszewski, Hartmut Hildebrand, Jean-Jacques FabreIEMN - DOAE Université de ValenciennesLike any physiological phenomena, the integration of biomate-rials is controlled by different biological processes. One of themost important is adhesion quality between tissues and implant.The mechanical properties of the interface cells/substrate are di-rectly related to the quality of adhesion. Only some techniquesare able to give quantitative information on this adhesion, andnone to our knowledge uses ultrasounds however known to bean efficient tool in mechanical properties investigations. Our ob-jective is to observe the behaviour of adherent MC3T3-E1 sub-jected to a quantified insonification. The cells were cultivated ona glass substrate during 3 days. We used continuous longitudi-nal waves to apply variable and quantified ultrasonic stress oncell culture. Two parameters of the insonification were investi-gated: frequency and power. Initially the cells detached duringexperimentation are counted in order to obtain curves of detach-ment according to the desired parameter. Secondly, we observedusing a laser interferometer the amplitude of the oscillations un-dergone by the cells during the insonification. We succeeded inestablishing the link between observations made with the inter-ferometer and the curves of cellular detachment. This link madeit possible to obtain a value of the cells adhesion force for theconsidered substrate and time of culture.



Safety of Diagnostic Ultrasound: Relevance of TI, MI, SafetyClass, ETI or RTI, EAS or RASJoachim HerbertzUniversität Duisburg-EssenSafety of the patient in the ultrasonic field is subject of controver-sies. Key to fundamental controversies is the question, whethersafety is of minimal concern, if an ultrasonic field is neither a ther-mal hazard nor a cavitational hazard. As in that case the hazardwould be of minimal concern, exposure of a patient would notconstitute a risk of concern. In the commercial approach, ap-plication of the ALARA principle by the operator on the basis ofindicated indices TI (Thermal) and MI (Mechanical) is said to es-tablish safety of the patient. These indices and the presumption,that any exposure constitutes a risk, are propagated via the Inter-national Standard IEC 60601-2-37. The Harmonised Europeanversion of that Standard has not come into effect in Germany.Based on the consensus of the international experts in the ’Ultra-sonics’ Committee 87 of the IEC in April 1999, the Safety Stan-dard GEFAU N 01 has been published in May 2001. This SafetyClassification uses the physical parameters relevant to thermaland cavitational hazard and their biological threshold values. Ifany limit of Safety Class A is exceeded, the extent of the excessis indicated to the operator, for instance by the parameters ETIor RTI and EAS or RAS, and by indication of Safety Class B. On-going research on bio-effects does no longer justify further delayof implementation of the Safety Classification, as existing equip-ment may pose a risk to the patient while the relevant scientificbasis has not changed since more than a decade.


Multichannel Recording and Classifying of RespiratorySoundsFranz Graf, Karl Putz, Gert Wurzinger, Ulrike Kleb, Hans KöhlerJoanneum ResearchThe auscultation of the lung by means of a stethoscope is an im-portant and straightforward diagnostic method. It is the simplestand least intrusive technique to determine direct information re-garding the structure of the required lung tissue. The variationsin the sound of the lungs are in direct relation to the pathologi-cal variations of the lung. Based on the variety of the heard lungsounds, it is often difficult to make a precise diagnosis. Thereforea system for multichannel recording and classifying of respiratorysounds was developed. First several kinds of sensors were con-structed in order to obtain high-quality respiratory sounds. Thedata collection was realized with two off-the-shelf data acquisition


cards, the upstreamed the voltage supply of the sensors and anaeroplethysmograph. The devices are controlled by a softwarewhich has the further purpose to collect additional data for statis-tical analysis. In a clinical trial more than 60 persons with differentkinds of diseases were examined. The analysis and classificationwas done by using different methods of digital signal processing,statistics and stochastics. The results of the study will be pre-sented.

We. 8:30 Oberlin Ultrasonic non-destructive testing

NDE OF Materials Properties by UltrasoundsAli Badidi Bouda, Rafik Halimi, Mourad Benzohra, Amar Ben-chaalaCentre de Soudage et Controle CSCThe ultrasonic waves, with the matter interaction study, is an in-creasingly effective tool for qualitative and/or quantitative charac-terization of industrial materials. In this article we describe ex-perimental studies, which were the work object at the Weldingand Control Center (CSC), based on the measurement of somesimple ultrasonic parameters such as propagation velocities andattenuation coefficients of the longitudinal and transverse wavesthrough various samples. These measurements were taken onsamples of suitable nature , shape and dimensions and eventu-ally heat treated in order to obtain the required properties. Theanalysis of the obtained results showed that one can determine,by simply measuring the parameters above cited, quantitativelywith an appreciate precision: éæ the second elastic constants ofseveral materials éæ the width of the heat affected zone (HAZ)of a welding operation which is a representative parameter of theweld quality . éæ the third elastic constants of some materials if atensile testing machine is available. This experimental work, also,shows the possibility to assess the qualitative hardness and grainsize [1, 2] of a steel only from its longitudinal velocity wave. Theexperimental results obtained are compared with those obtainedby classical methods or quoted from the literature, discussed andanalyzed in order to develop non destructive techniques for ma-terials characterization by ultrasounds. [1] A. Badidi Bouda &al Ultrasonic characterization of materials hardness, Ultrasonic,vol.38, 2000, pp224-227 [2] A. Badidi Bouda & al, Grain SizeInfluence On Ultrasonic Velocities and Attenuation, NDT&E In-ternational, in press.



A Parametric Model of Acoustical Signature including Atten-uation and Electrical Responses of Transducer and Measur-ing ChainJérôme Mathieu, Christian Fasolo, Gilles DespauxLAIN, Univ. Montpellier IITransducers used in ultrasound microscopy are usually consti-tuted with a delay line in which a small lens is hollowed out. Thedelay line is designed in a way that the field produced by thepiezoelectric element is relatively plane at the level of this lens.The classical models of acoustic signature V(z) include the ul-trasound field effects onto V(z) into a function called the pupilfunction. Now these models make systematically some hypothe-ses : the lens is supposed to be smooth, axially centered andthin, the field is supposed to be zero outside the lens, and so on.Furthermore, the classical models don’t include either the elec-trical responses of transducer and measuring chain, or the at-tenuation inside the delay line and the coupling media. It resultsfor V(z) big differences between theory and experiments. In thisarticle, a parametric model of V(z) is proposed. The aim is to ob-tain the amplitude of V(z) more accurately than with the classicalmodels. It is based on the same propagations’ theories than thelast ones, but introducing some parameters and adding the at-tenuation and the electrical responses mentioned above. Thesechanges with regard to the classical models were introduced oneby one, which enables to determine for each change its relativeextent in the differences observed between theory and experi-ments in V(z). For each parameter or additional effect taken intoaccount, an experimental procedure is described to determine it.Some experiments support our comments.


Defect Detection by Split Spectrum Processing and DiscreteWavelet Transform in Coarse Grains MaterialsRedouane Drai, Abdesselem Benammar, Mohamed Khelil, AmarBenchaalaCentre de Soudage et Controle CSCIn some metallic materials with coarse grains, signal energy islost due to scattering so the detection of defects by ultrasoundsis often difficult. This noise can mask the defect signal and cre-ates a constraint in its detection. It is thus necessary to increasethe visibility of the defect by techniques based on the analysisof defect echo spectrum. The ultrasonic echo nature is non-stationary, this is due to the nonuniform propagation mediumand which contains discontinuities, which causes the variation


of the frequency of the wave received compared to the emit-ted wave. This situation can be still complicated if the materialhas a coarse grains. In this work, we propose to develop onthe first hand, algorithms based on Split Spectrum Processing(SSP) with Q constant method associated to ’Group delay mov-ing entropy’ (GDME), on the second hand, we develop a methodbased on Discrete Wavelet Transform (DWT). These algorithmsallow detecting and locating imperfections echoes drowned in thestructural noise of materials. The investigation is performed withknown defects echoes with different characteristics (position, am-plitude, center frequency and bandwidth). The defect echoes fre-quency is varied around the frequency of the input signal in orderto evaluate, by SNR calculation, the robustness of the detectionmethod. The grain noise signal is generated first, by a simpleclutter model which consider the noise, in the time domain, asthe superimposed of signal coming from backscatterers in themedium and second, experimentally by a material with a coarsegrains.


Early defect recognition using Nonlinear Ultrasonic Reso-nance Spectroscopy (NURS)Igor Solodov, Klaus Pfleiderer, Jürgen Wackerl, Gerhard BusseInstitute for Polymer Testing and Polymer Science (IKP) -Nondestructive Testing-(ZFP), University of StuttgartConventional ultrasonic equipment for non-destructive evaluation(NDE) widely used in industry and technology for material char-acterisation and quality assessment makes use of so-called lin-ear elastic response of materials that results in the amplitude andtime variations of the input signal due to its scattering, reflectionand transmission. The nonlinear approach to NDE discussed inthis paper is concerned with non-linear material response, whichis related to intrinsic frequency changes of the input signal dueto acoustic wave interaction with material flaws. As a result, inaddition to the eigen-frequencies the NURS acquires new non-linear frequency components (higher harmonics, subharmonics,frequency side-lobes, etc.) that carry information on local mate-rial imperfection. By monitoring the local nonlinear spectral re-sponse (nonlinear spectroscopy), the nonlinear NDE modes ap-peal directly to the vulnerable (faulty) areas within a material or aproduct. Such a nonlinear NDE-methodology is extremely sensi-tive to a wide-range of imperfections and can deliver unique infor-mation about deterioration of material properties, early stage ofdefects development in components, integrity, quality and lifetimeof the manufactured products. The paper includes the study andapplications of the unstable modes of the nonlinear spectroscopy


caused by acoustic wave-defect interaction: nonlinear shift of res-onance frequency, fractional subharmonic and self-modulationinstabilities, bistability and transition to dynamic chaos.


Imagerie du bois par ultrasonsVoichita BucurCentre de Recherhes Forestieres de Nancy, INRAThe purpose of this report was firstly to obtain an ultrasonic im-age with a thin (2 mm thickness) solid wood specimen, withouta special preparation of the surface, specimens which are usedcurrently for X-rays microdensitometric technique, and secondly,to obyain an ultrasonic image of a very thin microscopic section(12µm), fixed between two glass lamellae. This specimen is theclassiccc specimen used for optical microscopic studies of woodanatomic structure. The images were obtained with the scanningacoustic microscope SONOSCAN C SAM D 9000, in a frequencyrange between 100 MHz and 230 MHz, for two species : spruceand oak. THe image resolution was between 10 µm and 25 µm .It was possible to establish a relationship between the amplitudeof the ultrasonic signal and the corresponding microdensitoùmet-ric values of different anatomical elements


Characterisation of small cylindrical scatterers by Decom-position of the Time Reversal Operator : Theory and Experi-mentJean-Gabriel Minonzio, Claire Prada, Mathias FinkESPCI - LOAWe propose to use the D.O.R.T. method to improve character-ization of sub-wavelength scatterers with conventional transmitreceive arrays like those used for medical imaging. The D.O.R.T.method consists in the measurement of the array response matrixK, and the diagonalization of the corresponding time reversal op-erator KK*. In most former studies, a one to one correspondencebetween the eigenvectors of the time reversal operator and thescatterers in the medium was shown. This correspondence, validin most experiment, is only true for isotropic scatterers, that isfor point like inhomogeneities of compressibility. The question wenow try to answer is : can we observe several eigenvalues forsub-wavelength object? From the associated eigenvectors, canwe get information on the physical parameters of the object asthe size, the compressibility, or the density? Simulations takinginto account the contribution of the different vibrations modes ofthe object have improved the understanding of the eigenvectorsof the time reversal operator for the small object. For an elastic


very thin cylinder, monopole and dipole scattering terms are thetwo significant ones, it is then possible to calculate analytically theeigenvectors of the TRO for a linear array. We will present exper-imental results obtained with the 128 channels electronic device,using a 1.5 MHz 128 elements array and 0.2 to 0.4 mm cylindri-cal nylon or steel wires. A good agreement between results andsimulations is shown. (1) french acronym for Décompostion del’Opérateur de Retournement Temporel


Nonlinear Elastic Wave Spectroscopy in Quenched MetallicSamples With Contact Calibrated Ultrasonic MeasurementsSerge Dos Santos, François Vander Meulen, Lionel Haumesser,Michel Vila, Jérôme Fortineau, Olivier Bou MatarGIP Ultrasons/ LUSSIThe nonlinear acoustic parameter (beta) is of great interest formaterial characterization for non-destructive testing in industrialapplications such as aircraft company. Furthermore, NonlinearElastic Wave Spectroscopy (NEWS) comprise a new class of in-novative ultrasonic techniques that provide extreme sensitivity indetecting damage in the form of microcracks or delaminations.The sensitivity of nonlinear methods to damage hide a great dif-ficulty for : i) obtaining calibrated absolute measurement of non-linear effects: ii) performing accurate models including nonlinearand hysteretic state relation of microcracks. In this paper, we pro-pose an experimental characterization of the nonlinear acousticparameter of steel samples previously bounded by water and oilquenching using an ultrasonic contact calibrated measurementset-up. A high frequency signal is inserted in the sample by acontact-transducer. A low frequency pulse is applied to the otherside such that the nonlinear interaction takes place during theback propagation. This interaction creates a phase modulationof the HF wave which is proportional to beta and to the particlevelocity of the LF pulse, determined by self reciprocity calibra-tion of the transducer. This method, previously validated in solidplates has been applied in metallic parts (XC48 steel) with dif-ferent crystallographic structure induced by austenite-martensitetransition. The stress-strain relation resulting from microstruc-ture in the austenite-martensite transformation induce a phasemodulation coefficient proportional to the nonlinear parameter.Experimental results showing the dependency between the steelquenching process and the nonlinear parameter measurementwill be presented.



Angular spectrum modelling of longitudinal guided wavepropagation in a embedded cylinder - Application to the non-destructive evaluation of grouted tendonsAnne Grimault, Laurent Laguerre, Marc DeschampsLCPCSteel members of civil engineering structures undergo degrada-tions due to corrosion and mechanical fatigue mainly, which canlead to its ruin in a long term. Hence, non-destructive inspectiontechniques are needed to monitor these structures. In this study,we are more particularly interested in non-destructive evaluationof bridge post-tensioned tendons using longitudinal mechanicalguided waves. As by construction, the tendons have a singleaccess to their ends (tendons are embedded over their wholelengths), the use of the guided propagation can have some ad-vantages to inspect a given length from this single point (reflec-tometry technique). Nevertheless, the conditions of propagationin a waveguide (the tendon) are strongly influenced by its geom-etry and the embedding material. In order to propose an adaptednon-destructive evaluation methodology, a model of propagationis studied. This work is focused on the determination of the ex-act solution of a cylindrical waves beam propagation, limited intime and space, inside a solid concentric cylinder embedded ina vacuum, liquid or solid (the steel tendon will be considered asa cylinder of same diameter). The model is based on the angu-lar spectrum method and a Fourier-Bessel analysis to predict thespatio-temporal elastodynamic fields. Two types of approachesare then possible. A local analysis which describes the solutionsas a partial waves series (Debye’s series expansion) for the re-flection/refraction of cylindrical waves at the steel/grout interfaceand thus allows an immediate physical interpretation. A globalresolution which presents a condensed mathematical form of theabove-mentioned local analysis.


Nonlinear interaction of ultrasonic waves studied with Fre-quency Response Function (FRF) analysisAlexei Moussatov, Bernard CastagnèdeLAUMThere is a growing interest for ultrasonic nonlinear techniques toassess and characterize damages in materials and structures.The presence of cracks drastically increases the nonlinearity ofa material. Consequently, to analyse the interaction betweenindependent ultrasonic waves there is a very sensitive and effi-cient method, i.e. the interaction of a powerful ultrasonic pump


wave with a probe wave at a smaller amplitude. For instance,if the pump wave is amplitude modulated, the interaction dueto the presence of cracks takes place in the form of a modu-lation transfer from the pump wave to the probe wave depend-ing on the amount and sizes of the damaged features inside thematerial. Glass plates (230x190x15mm) with limited damagedzones (around 1cm) have been tested over the 30-110kHz band-width. In order to obtain precise and robust results, FrequencyResponse Functions (FRF) of the plates have been recordedwith and without non-modulated pump. Correlations between theFRF variations (with and without pump) and the observed cor-responding side lobes on the related amplitude spectra of theprobe wave (when pump is amplitude-modulated) have been ob-served, explained and documented. Analysis of FRF deviationcaused by an external powerful ultrasonic excitation of a dam-aged object constitutes a new NDE method. This method diddemonstrate a strong potential to detect slight defects. A. Mous-satov, B. Castagnede, V. Gusev, ’Frequency up-conversion andfrequency down-conversion of acoustic waves in damaged ma-terials’, Phys. Lett. A, 301, pp.281-290 (2002). A. Moussatov,V. Gusev, B. Castagnède ’Self-induced hysteresis for nonlinearacoustic wave in cracked material’ Physical Review Letters - V.90,No.12, pp.124301/1-124301/4 (2003).


New Approaches to Ultrasonic Characterization and NDT ofWoodKlaus Pfleiderer, Inna Richter, Igor Solodov, Gerhard BusseInstitute for Polymer Testing and Polymer Science (IKP) -Nondestructive Testing-(ZFP), University of StuttgartUltrasonic characterization and NDT of flaws in wood is usu-ally complicated due to high acoustic damping and sensitivity ofthe material to coupling media. However, wood also has somepeculiar properties beneficial for development of new ultrasonicNDT methodologies. The approaches reported in the present pa-per make use of its high elastic anisotropy, nonlinearity and lowacoustic impedance. An orthotropic symmetry of wood results inthe acoustic birefringence for shear waves. A simple techniquesuggested to determine the fibre orientation is based on mea-surements of the delay and amplitude of shear waves as func-tions of the azimuth angle of transmitter polarization. The lowacoustic impedance facilitates air-coupled ultrasound transmis-sion in wood. The focused slanted transmission mode of the air-coupled ultrasound was adopted for non-contact measurementsof local elastic anisotropy of wood plates and veneer specimens.


Higher harmonic and subharmonic modes of nonlinear vibrome-try were used for nonlinear imaging and NDT of flaws (delamina-tions, cracks, knots, poorly bonded areas, etc.) in wood-basedmaterials and products.


Etude de la diffraction d’une onde plane dans une inclusionélastique par une méthode numérique coupléeSlim Soua, Hédi Bel Hadj Salah, Mabrouk Ben Tahar, Abdelwa-heb DoguiLaboratoire Roberval, CNRS, Université de Technologie de Com-piègneDans beaucoup d’applications en contrôle non destructif par ul-trasons ou en géophysique, on est amené à étudier l’interactiond’une onde élastique avec une hétérogénéité localisée. Lerésultat de cette interaction peut donner des informations surl’hétérogénéité (géométrie, matériau, emplacement, effet de con-centration de contrainte dynamique, ect..). Pour une géométriesimple, il est possible de traiter ce problème d’une manièreanalytique ou quasi- analytique (méthodes basées sur la dé-composition en ondes planes, méthodes modales), dans lesautres cas les méthodes numériques sont les plus adaptées.Plusieurs techniques ont été utilisées : méthode des élémentsfinis, méthode des différences et méthode des éléments finisde frontières basées sur les représentations intégrales. Cha-cune de ces méthodes est mieux adaptée à une configura-tion donnée de ce problème. Nous présentons dans ce travailune méthode couplée éléments finis / éléments finis de fron-tières pour étudier la diffraction d’une onde élastique incidenteémise dans un milieu élastique homogène et isotrope par unehétérogénéité localisée. L’utilisation d’une méthode d’élémentsfinis de frontière, déterminée à partir d’une formulation intégraleindirecte, permet de bien prendre en compte la condition de ray-onnement à l’infini lorsque le domaine élastique homogène estnon borné. Pour palier à sa limitation aux milieux homogènes, onlui associe une méthode d’éléments finis qui est plus appropriéepour modéliser les hétérogénéités et les anisotropies localisées.Nous appliquons cette formulation à des problèmes plans. Onprésente quelques applications qui mettent en évidence l’effet dela géométrie, de la rigidité relative et des dimensions pour dif-férents types d’inclusion sur le champ diffracté.



Global Approach for the ultrasonic Structural Health moni-toring of concreteMaher Shaira, Hossam Elaqra, Rachid Elguerjouma, PhillipeGuyInsa de Lyon- GemppmA global approach for the continuous damage monitoring in con-crete is performed. This approach uses ultrasonic wave propaga-tion and acoustic emission simultaneously on instrumented con-crete samples. During a tensile test, ultrasonic velocity and atten-uation dispersion are measured, simultaneously acoustic emis-sion is collected. The occuring damage is characterised by thisglobal approach till the rupture of the sample. Good correlationsare found between ultrasonic velocity decrease, attenuation in-crease and acoustic emission events. Furthermore, the evolutionof the velocity and the attenuation dispersion associated to theacoustic emission analysis during the tensile test allow to dis-criminate between different damage phenomena. This global ap-proach on an instrumented samples appear to be very efficientfor the structural health monotoring of materials and structures


Creep Damage and failure of Polymer Based Composites: Non-Destructive Evaluation with Ultrasonic Waves andAcoustic Emissions and ModellingNechad Nechad, Rachid Elguerjouma, Agnes Helmstetter, DidierSornetteInsa de Lyon- GemppmThe creep behaviour and the damage mechanisms of cross-plyglass fibre reinforced polymer composites are investigated us-ing ultrasonic wave propagation and Acoustic Emission (AE). Themechanisms of the damage events and their space-time localiza-tions are identified from AE. Simultaneously, the longitudinal ul-trasonic velocity is measured in situ by transmission through thecomposites. The AE is very well correlated with the loss of stiff-ness determined from ultrasonic velocity measurements. For thestrain (respectively AE), an Andrade (respectively Omori) law de-scribes the first (primary-creep) regime of the creep test. The lat-est (tertiary-creep) regime is characterized by a finite-time powerlaw singularity culminating with the global failure of the sample.The correlation between AE primary creep and the AE tertiarycreep leeding to the failure of the material is investigated. Theseresults are rationalized by a simple mechanical model, formu-lated in terms of a democratic Kelvin-Maxwell fibre bundle modelwith non-linear viscosity. Analytical expressions of the strain and


the AE are derived as function of time and are checked by nu-merical integration of the equations. A good agreement is foundbetween experiments and the model prediction, particularly forstrain and acoustic emission power-laws scaling in the primary-creep regime and in the tertiary-creep neighbourhood of rupture,which is consistent with power-law seismic activation observedprior to some earthquakes.


Design of Low Frequency Ultrasonic Sensors for CheeseDraining InvestigationMarie Nawal Sabra, Georges Nassar, Bertrand Nongaillard,Yolande NoëlIEMN - DOAE Université de ValenciennesThe quality evaluation of food products is of great interest to thefood industry for two main reasons. Firstly production should befairly repeatable in order to gain trust in the market. Secondlyfood processing should be up to the hygienic norms to preserveconsumer health. To reach these goals, we propose a new ultra-sonic system working by through-transmission in the frequencyrange of 100-200 KHz. The system is made of ultrasonic pointsources and is used in order to follow the mechanical proper-ties of cheese during the early phases of the process. We willpresent the specialized sensor system designed for this purposeas well as a comparison between the system’s model and exper-imental results and its application to the evolution of the mediumwhile draining. Results show a good prediction via ultrasonic ve-locity measurement of the mechanical properties throughout thechange of the physical state of the medium. This method will belater used to study the effect of parameters interfering in the con-solidation of cheese grains during draining on the final quality ofcheese.


Non Destructive Testing to detect the action of the sulfito-reducing anaerobic bacteria by ultrasonic method in tinnedfoodJ. Abrehouch, B. Faiz, Ali Moudden, Dominique Decultot,Gérard MazeLaboratoire d’Acoustique Ultrasonore et d’Electronique (LAUE),UMR CNRS 6068The sterilisation in the tinned foods aims at the wholesome-ness and the bacteriological stability of foods. The clostidiumbotulinum which is an sulfito-reducing anaerobic bacterium ischoice in this work as a reference bacterium because of its strong


heatproof. The analyse by a microbiologic method entails ster-ilised material and very strict work conditions. Moreover theseanalyses are slow and expensive. Negative results obtained onsamples subjected to an examination do not indicate that theyare not entirely wholesome. In this work, we utilise an ultrasonictesting to detect the effects of the sulfito-reducing anaerobic bac-teria on foods. The samples take place in a parallelepipedic tank.They are insonified by a short ultrasonic pulse. The reflectedsignal is detected and amplified, it is digitised by a numericaloscilloscope and transmitted to a computer by a IEEE 488 in-terface. These signals are treated by the computer to determinethe viscoelastic parameters of the samples (phase velocity andattenuation). The evolution of these parameters as function oftime allows us to know the different phases of the developmentof clostridium botulinum bacteria. The results show also the ef-fect of the bacterial charge on the evolution of different phases.

We. 8:30 Arp 1 Building acoustics II

Sound Insulation of Solid Wood ConstructionsJoachim Hessinger, Hans-Peter Buschbacher, Andreas Rabold,Fritz HoltzLSW - Labor für Schall- und Wärmemesstechnik GmbHSolid wood constructions in form of laminated timber boards orcase-type-building elements have become the basis of many dif-ferent building elements, like timber floors, walls and roofs. Yetthe knowledge on the sound insulation of these elements is rathersmall. For that reason a research project on the sound insula-tion of solid wood constructions was initiated by German soci-ety for wood research (Deutsche Gesellschaft für HolzforschungDGfH e.V.). Acoustic measurements were performed at the LSW- Labor für Schall- und Wärmemesstechnik GmbH and the re-sults of a preliminary report will be discussed in this paper. Theairborne- and impact-sound insulation of walls and floors built ofsolid wood constructions has been measured in a test facility ac-cording to ISO 140. The test elements displayed the variety ofsolid wood constructions currently available from timber industry:laminated-timber-boards, case-type-building elements. Althoughthe airborne sound insulation of the different basic timber con-struction displayed a great scatter within the results. However assoon as a lining (floating screed, thermal insulation of the wall) isapplied to the wall / floor the different elements behave very sim-ilar within the frequency dependent R and the Rw. The differentfloor elements under investigation showed an impact sound insu-lation that behaved quite similar within the frequency dependentLn and the Ln,w. For practical reason it is therefore sufficient to


classify the different construction types of solid wood construc-tions within one class of elements.


Airborne Sound Insulation in Studio RoomsFrank Schnelle, Roland KurzKurz u. Fischer GmbHThe requirements for the airborne sound insulation between stu-dio rooms depend on the necessary sound level difference. Itis determined by the highest sound levels in the source roomand the permissible background noise level in the receiving room.Studio rooms are built as ”Room-in-Room-System”. Usually, par-titions between rooms are lightweight multi-layered constructions.Various measurement results from new and refurbished studiobuildings built with system elements will be presented. The sys-tem components are manufactured as lightweight metal boardpartitions, suspended ceilings and floating floors. Predictions ofsound insulation from partitions without and with windows/doorswill be compared with measurement results. Further, it will befocused on the sound insulation at low frequencies, which is atypical problem for this kind of construction.


Messergebnisse des Schallschutzes im Wohnungsbau -statistische AuswertungenChristian Burkhart, Agnes SchwartzenbergerAkustikbüro Schwartzenberger und BurkhartStatistische Auswertungen von Messergebnissen der Luft- undTrittschalldämmung werden häufig zur Begründung von An-forderungen und zur Beurteilung des Schallschutzes herange-zogen. Häufig wird auch eine mittlere Art und Güte als Mit-telwert aus statistischen Auswertungen abgeleitet. über Sinnund Unsinn derartiger Betrachtungen und den Grenzen der An-wendbarkeit wird berichtet und auf häufig anzutreffende Fehlin-terpretationen hingewiesen. Eigene Messdaten der letzten 10Jahre wurden statistisch ausgewertet, die Ergebnisse werdenvorgestellt.



Bauakustische Anforderungen - Vergangenheit und ZukunftAgnes Schwartzenberger, Christian BurkhartAkustikbüro Schwartzenberger und BurkhartBauakustische Anforderungen - Vergangenheit und ZukunftDie Neufassung der DIN 4109 ist in Bearbeitung und überdie zukünftigen Anforderungen von 2- oder 3-stufigen An-forderungsniveaus wird heftig diskutiert. Die Gegner eines 3-stufigen Anforderungsniveaus befürchten die Einführung des mit-tleren Niveaus als allgemein anerkannte Regel der Technik unddamit eine Anhebung der Anforderungen. Als beratender Inge-nieur und Sachverständiger ist man mit allen Baubeteiligten inengem Kontakt und erlebt die typischen Bauweisen, deren Prob-leme, regionale Unterschiede und Bedürfnisse (nicht zu verwech-seln mit den Erwartungen) der Bewohner an erster Stelle. EinBlick über den deutschen Tellerrand hinaus führt zu interessan-ten Lösungsmöglichkeiten, die vorgestellt und diskutiert werdensollen.

We. 9:50 Arp 1 Flow noise

Optimisation of correlation function models for statisticalaeroacoustic noise predictionRosa Wells, Peter Jordan, Yves GervaisLaboratoire d’Etudes AérodynamiquesThe use of statistical approaches for the prediction of acousticradiation from aeroacoustic systems generally involves modellingthe spatiotemporal correlation of some system parameter (veloc-ity in the case of unbounded flows, pressure in the case of sys-tems containing solid boundaires). An intrinsic limitation of allstatistical approaches, resulting from the low acoustic efficiencyof aeroacoustic systems, resides in the error incurred in mod-elling such quantities, as an error which can be larger (by asmuch as an order of magnitude) than the actual acoustic energyradiated. If such approaches are to have any chance in the quan-tititive modelling of aeroacoustic noise, they need to be extremelyaccurate. In this work different analytical models are examinedwith a view to accurately reproducing the true character of thetemporal correlation of the turbulence velocity components impli-cated in the generation of subsonic jet mixing noise. These mod-els are validated using Laser Dopler Velocimetry measurementsperformed in the mixing layer of such a jet. Subsequently, usingLighthill’s formalism, the models are used to derive expressionsfor the farfield sound intensity spectra, and these are comparedwith acoustic measurements performed on the same jet. Thiswork was supported by the EU research program JEAN (contractno. G4RD-CT-2000-00313).



Stability of an Axisymetric jet with Variable Velocity Periph-erical FlowVincent Fleury, Christophe BaillyCentre Acoustique - Ecole Centrale de LyonThe acoustic emission of supersonic sheared flows is known tobe mainly due to instability waves as shown by Tam & Burton(1984). However, this noise mechanism is still debated for sub-sonic flows, see e.g. Crighton & Huerre (1990). With this aimin view, the linear stability of a round incompressible jet is in-vestigated. A tangent hyperbolic velocity profil controlled by theparameter Ru = (Uj-Uinf)/(Uj+Uinf) is chosen with Uj and Uinfthe speeds of the jet and the peripherical flow respectively. Thelong time behavior of small amplitude perturbations of the axiallyslowly divergent free jet, i.e. for Ru = 1, has been recently pre-dicted by Cooper & Crighton (2000) thanks to the global linearstability theory. In the present work, both cocurrent (Ru<1) andcountercurrent (Ru>1) configurations are investigated. First, alocal stability analysis along the jet axis is performed. The insta-bility is searched as a normal mode of complex pulsation, com-plex streamwise wave number and azimutal number n. We focuson absolute instability modes. Critical Ru parameters delimitingabsolute stable and unstable behavior are calculated. Thus theaxisymetric mode n = 0 is found unstable on a bounded axialrange for Ru > Ruc0 =1.191. In the case n = 1, we exhibit athreshold Ruc1 = 1.388. Global linear stability criteria are thenapplied and the critical global parameter Rucg is calculated atleading order in function of the ratio between the initial momen-tum thickness and the jet diameter. Our results are compared toStrykowsky & Niccum’s (1991) experimental data.


Jets Instabilities Producing the Slot-ToneAlexis Billon, Vincent Valeau, Anas SakoutLEPTAB Université de la RochelleThe nature of the instability governing the self-sustained tonesproduced by a low Mach number free plane jet impinging on aslotted plate, known as slot-tone, is identified experimentally. Theexperimental apparatus permits to control the Reynolds numberand the distance from the jet outlet to the plate. For a Reynoldsnumber, the shear-layer natural frequency and the jet columnmode frequency of the free jet without the obstacle are estimatedand compared to the minimal and maximal frequencies of thetones (for any position of the plate). The frequency of both insta-bilities defines the frequency domain of the self sustained tones.


The lowest frequency of the tones, obtained when the plate isplaced downstream the end of the potential core, are the re-sult of the amplification of the column mode frequency. On theother hand, the maximal frequency of the tones, obtained whenthe plate is situated near the jet outlet, is close to the naturalshear-layer frequency. Moreover, when the tones frequency ishigher than the natural shear-layer frequency, the sound pres-sure level produced is very inferior to the maximal sound pres-sure level measured at the same Reynolds number. This con-firms the prominent role of the shear-layer instability in the self-sustained tones process for the highest frequencies. Tones witha frequency lower than the jet column mode frequency are rarelyobserved.


Numerical Simulation of Aeroacoustic Problems Using Lat-tice Boltzmann MethodDenis RicotRenault - Research Department, Acoustic Group - TRC RUC 405The lattice Boltzmann method (LBM) is an innovative numericalmethod based on kinetic theory to simulate various hydrody-namic systems. The lattice Boltzmann method simulates thetime-dependent motion of a perfect gas at low Mach numberthat is governed by the compressible Navier-Stokes equations.The theory of this new numerical scheme is reviewed and atwo-dimensional solver based on the well-known nine-velocitymodel is developed for aeroacoustics simulations. The usualissues of CAA codes are treated such as the non-reflectiveboundary conditions and the damping of short numerical waves.Test case simulations show that the LBM is a low-dissipativescheme : it is therefore possible to calculate simultaneouslythe aerodynamic and acoustic fluctuations of the flow. A directsimulation of the noise radiated by the flow over a rectangularcavity is presented.

In the framework of automotive simulations, a commercial codebased on LBM is used. Two main applications are presented.First, the prediction of pressure fluctuations on the externalsurfaces of a vehicle is studied. For high Reynolds number flows,a sub-grid turbulence model is used. The cutoff frequency of thisVery Large Eddy Simulation (VLES) approach is evaluated as afunction of the mesh resolution.

The second automotive application is the simulation of sunroofbuffeting. The LBM predicts the acoustic coupling between the


vortex shedding and the Helmholtz resonance of the passen-ger compartment. The frequency lock-on around the cavity res-onance frequency and the maximum amplitude of oscillation atthe critical flow speed are obtained. Then, LBM simulation canbe performed for the design of wind deflectors.


Diffraction and refraction effects in airfoil trailing-edge noisefree-jet experimentsMichel Roger, Stéphane MoreauCentre Acoustique - Ecole Centrale de LyonTrailing-edge noise is the noise radiated by an airfoil as bound-ary layer disturbances are convected past the trailing edge. Re-liable measurements of that noise are needed to assess analyti-cal models developed elsewhere and used to provide simple fanbroadband noise prediction methods. Dedicated experiments aregenerally performed in open-jet wind-tunnels. The airfoil is heldbetween side-plates at the nozzle of the wind tunnel and far-fieldmeasurements are made in the mid-span plane, outside the flow.The paper is devoted to the installation effects associated withone such experiment in the ECL facility with a thin cambered CDairfoil developed by Valeo, different flow regimes being obtainedby varying the angle of attack. The first effect is the jet deflectionobserved at non-zero airfoil loading; it is accounted for by usingthe mean pressure coefficient as an indicator of the flow condi-tions. The second one is the scattering of the noise emitted bythe airfoil at the nozzle lips, more severe in the upstream direc-tion because trailing-edge noise is known to radiate preferentiallyupstream as frequency increases ; a diffraction correction is com-puted using the SYSNOISE software and applied to analyticalcalculations, providing a very good agreement with the measure-ments. The third effect is the sound refraction at the jet shearlayers ; the relevance of a refraction correction usually made isre-addressed in view of the intended comparison with analyticalmodeling, including the effect of additional refraction across theairfoil boundary layers.



Numerical Modelling of Wake-Jet Interaction with Applica-tion to Active Noise Control in TurbomachnieryGraham Ashcroft, Jan SchulzInstitute of Propulsion TechnologyRecent experimental investigations have demonstrated the pos-sibility of using aerodynamic noise sources to generate the sec-ondary (anti-phase) sound fields for active noise control applica-tions in turbomachinery. One particular method proposed, de-veloped in cooperation between DLR and TU Berlin, for creatingsuch secondary aerodynamic noise sources is to employ high-speed air jets in the tip region in order to disturb the flow fieldaround the rotor blade. In this study we investigate the mech-anisms of noise generation of such a configuration, and thenconsider the application of this control strategy to a low-speedhigh-pressure axial-fan with a blade count ratio of unity. Numeri-cal simulations are performed for a single jet, per blade passage,located aft of the rotor trailing edge. The analysis focuses on thetemporal interaction of the rotor wake with the transverse high-speed jet. Time-accurate numerical simulations are performedusing a Reynolds-Averaged Navier-Stokes flow solver, with theeffects of turbulence modelled using a one-equation turbulencemodel. To mitigate spurious reflections at external computa-tional boundaries, non-reflecting boundary conditions based onthe Giles formulation are employed. To reduce computationaloverheads, a high-order accurate spatial discretization schemeis used. Results of the numerical simulations are compared withavailable experimental data.


Active control of tip clearance noise and aerodynamic per-formance of axial turbomachinesLars Neuhaus, Wolfgang NeiseDeutsches Zentrum für Luft- und Raumfahrt e.V., Institut fürAntriebstechnik, Abteilung TurbulenzforschungAxial turbomachines have a radial gap between the casing andthe rotor blades. The pressure difference between the suctionand the pressure side of the impeller blades drives a secondaryflow over the tip of the rotor blades. This tip clearance flow isdetrimental to the aerodynamic and acoustic performances ofthe machine, i.e., pressure rise and efficiency drop, the radiatednoise increases, and the usable range of the performance char-acteristic is diminished.


Previous work on the axial fan test bench at DLR-Berlin, inves-tigating the noise and performance effects of varying tip clear-ances showed the existence of a broad-band noise source forlarge tip-casing clearances.To control the flow conditions, air is injected into the gap throughslit nozzles mounted flush with the inner casing wall and dis-tributed uniformly over the casing circumference. As a result,the aerodynamic performance is improved and the tip clearancenoise is reduced. To optimize this effect, the axial location of theinjected air flow relative to the impeller position and its directionrelative to the main flow are varied.


Active Flow-Control for Reduction of Lift-Generated Air-frame NoiseLars KoopTechnische Universitaet Berlin, Hermann-Foettinger-Institut fuerStroemungsmechanikAirframe noise is a significant contribution to the total sound radi-ated during landing approach. One dominant source of airframenoise is situated at the side-edge of the extended wing-flap. Os-cillation of the side-edge vortex leads to pressure fluctuations atthe rigid surface and thus to sound radiation into the far field. Theobjective of the present study is to reduce this noise by blow-ing a jet of air into the vortical structure. The basic idea behindthis concept is to displace or weaken the vortex, reducing thesurface pressure fluctuations and thus the amplitude of the ra-diated sound. Measurements were performed with a A340 half-model in a wind tunnel. The angles of incidence and the flap- andslat-angles of the model can be varied. The extended flap wasequipped with a blowing facility. The noise emission was mea-sured with a phased microphone-array. In addition the flow fieldat the side-edge was investigated by means of particle imagevelocimetry and unsteady pressure fluctuations were measured.The array measurements show that the flap side-edge noise isdominant between 2500 and 6500 Hz and strongly dependentson the angle of attack of the model. The flap side-edge noise canbe significantly reduced by means of active blowing through theside-edge of the flap. The flow field in the vicinity of the side edgeshows two mechanisms that may be responsible for the noise re-duction: decrease of the peak-vorticity in the vortex core andpushing the vortical structure away from the side-edge surface.



Wind Noise - A dominant Source for In-Cabin Noise in Com-parison to other Noise Sources of a VehicleMatthias RiegelFKFSPrevious examinations of the vehicle interior noise look mostlyonly at single sound source such as engine noise or rolling noise,but don’t take into account their contribution to the overall noise.By measurements in the aeroacoustic wind tunnel and in thevehicle acoustics test stand the in-cabin contribution of wind,rolling and drive train noise are determined separately. There-fore measurements are carried out at different car speeds in dif-ferent gears on two different street pavements to determine theoverall noise and the appropriate engine speeds and loads. Al-ready at medium speeds wind noise is the most important soundsource for interior noise in the higher frequency range above 2kHz, independent of road surface and engine speed. Even in thelow frequency range wind noise can be louder than engine anddrive train noise. At low vehicle speed and high engine speed theengine noise is rather high, if the engine speed goes down therolling noise gets dominant. On concrete pavement the rollingnoise is even at high driving speed as loud as the wind noise.


Analytical solution for multi-modal acoustic propagation incircular ducts with laminar shear flowRomuald Boucheron, Hélène Bailliet, Jean-Christophe ValiereLaboratoire d’Etudes AérodynamiquesAn analytical solution for the propagation of sound in circularducts in the presence of laminar mean flow is derived. Thissolution, using Kummer’s formalism, generalizes previous re-sults found by Gogate and Munjal in the particular case of axi-symmetric modes [J.S.V. 1993 160(3), 465–484]. Connectionsbetween the solution and already known solutions of more par-ticular cases will be shown. The dispersion equation is estab-lished which allows the calculation of propagation constant. Theknowledge of propagation constant allows in turn to calculateacoustic pressure profiles. The evolution of propagation constantand acoustic pressure profile with Mach number and working fre-quency will be presented and discussed. These results are satis-factorily compared with previous numerical simulations. Disper-sion curves will also be presented non only for non-radial modes(as previously done by Bihhadi and Gervais [Acta Acustica 19942, 343–357] but also for radial modes. It appears that the effect ofshear flow is strongly linked to the radial order of the propagatingmode.



Attenuation of acoustical waves in duct with flowYves Auregan, Vincent PagneuxLAUMTwo main issues will be addressed in this communication. First,the attenuation in a rigid duct with shear flow is presented. Theflow is considered as quasi-laminar and asymptotic expansionsof the visco-thermal propagation equations are given. By com-parison with experiments it can be seen that this model cannotbe used for all the frequencies. Thus a model taking into accountthe effect of turbulence is presented. This model is comparedto experimental results and to numerical simulations (LES). Thesecond issue is the influence of visco-thermal effects on the ef-fective impedance of a liner located at the wall of the duct. Exper-imental results call the classical acoustical displacement continu-ity at the wall into question. Thus a new model based on MatchAsymptotic Expansion is presented.


Acoustical attenuation in a rectangular channel with turbu-lent flowMaud Leroux, Yves AureganLAUMThe attenuation of an acoustical wave in a tube in presence ofa turbulent flow is not a well known problem. Ronneberger andAhrens, and Peters et al. have measured the acoustical attenu-ation in a cylindrical tube with flow. They distinguish 3 zones asa function of the ratio of the acoustical boundary layer thicknessand the viscous sublayer of the turbulent mean flow boundarylayer. If the ratio is small, the damping of acoustical waves is notinfluenced by the turbulent stresses. If the ratio is large, a quasi-stationary theory can be applied. In the middle range, a strangebehaviour is observed: the acoustical stresses at the wall aresmaller with flow than without flow. This strange behaviour is stillnot understood. Direct Numerical Simulations of the turbulentflow are needed to understand this effect. In order to comparethese simulations in a plane channel to experimental results, wemeasure the attenuation in a rectangular tube (1.5 cm ×10 cm).The 3 zones described previously for the cylindrical geometry arealso observed in this case. A new model based on asymptoticexpansion of the propagation in a 2D duct with turbulent flow ispresented.



Predicting the Aerodynamically Generated in 2D-MufflersNoise and its Far-Field Propagation Using a CombinedLES/LEE ApproachWim De Roeck, Wim Desmet, Paul SasDepartment of Mechanical Engineering, K.U.LeuvenMufflers are often installed in ducted flow systems to attenuatethe noise generated by engines, fans, oe Under certain circum-stances, however, they may become flow-excited noise gener-ators rather than silencers. Up till now only limited research isrelated to the numerical computation of flow-induced noise in au-tomotive muffler applications. In the present paper, a combinedLarge Eddy Simulation-Linearized Euler equations (LES/LEE)approach is used to predict the aero-acoustic source field andits far-field propagation. This approach is applied to predict theflow-induced noise in a 2D-muffler and to gain some insight inthe noise generating mechanisms such as tailpipe and chamberresonances. An evaluation of different kind of source terms in theLEE and their effects on the generated sound field is presented.The acoustic near-field results are compared with LES-results tovalidate the different kinds of acoustic source terms and to eval-uate the use of a combined LES/LEE approach to compute thegenerated sound field in a 2D-muffler. The acoustic far-field willbe compared with acoustic analogy calculations based on theFfowcs-Williams/Hawkings (FWH) analogy. The effect of the flowfield on the propagation of acoustic waves will be investigatedby comparing LEE-results that incorporate the flow field, with theFWH-results that assume a medium at rest.


Application of Laser-Scanning Interferometry on Aeroacous-tic ProblemsMartin Fischer, Marco ZucchiniRobert Bosch GmbH, Corporate Research and Development,FV/FLP AcousticsPrediction of flow-induced noise is an object of intensive ongo-ing research. Statistical properties of pressure fluctuations of theunsteady fluid flow or of sound waves can be mapped by meansof laser-scanning interferometry. External microphones or flowprobes can serve as reference sensors. Animation of interest-ing turbulent flow events and of the generated and propagatingsound waves leads to a deeper understanding of aeroacousticsound generation. Besides this qualitative analysis the fluctuat-ing pressures can be evaluated quantitatively in the case of sym-metrical flow configurations. The experimental data sets obtained


by means of laser-scanning interferometry are useful for compar-ison with numerically modelled sound fields based on CFD-data.In this way, CAE tools for the prediction of flow-induced soundcan be calibrated. The application of this new method is shownfor different elementary and technically relevant sound sources.


Microphone Array Measurements for Aeroacoustic Investi-gations Using a Frequency Band Filtering MethodAndreas Zeibig, Christian Schulze, Joern HuebeltInstitut für Akustik und SprachkommunikationWithin the scope of the research project SWING+ (Simulation ofWingFlow Noise Generation) it is necessary to develop a micro-phone array to localize sound sources on a generic wing pro-file. As a first approach a line array was constructed. Using thisline array a lot of basic investigations with various array geome-tries and signal processing methods were carried out. As a resultof these basic investigations the optimal configuration for a linearray was found consisting of eight equal spaced microphones.This geometry can be used over a broad frequency range, if aspectral band filtering technique is applied. This way a narrowmain lobe as well as a reasonable side lobe suppression can bereached. Reference measurements were carried out to prove thefeasibility of this method. During the reference measurementsacoustic model sources like monopole and dipole were localizedand separated. Afterwards the use of this microphone array forthe localization and separation of aeroacoustic sound sourceson a generic wing profile and a cylinder in an air flow will bedescribed. From these measurements useful experiences andknowledge for the design of a two-dimensional microphone arraycould be obtained.


Estimation of installation errors in acoustic flowrate mea-surements by CFD-modelingSegey Ruchkin, Michael RychagovMoscow Institute of Electronic Technology (Technical University)The results of investigation concerned with the development ofnew computer-based models for ultrasonic multipath time-of-flight measurements of perturbed flows as well as the data ofcorresponding numerical modeling are presented. Up-to-datealgorithms for numerical modeling of the problems of diametraland chord acoustical measurements enable to obtain with highprecision (1,5 - 2 %) an axisymmetric flow velocity profile v(r) atsteady-state flow conditions in an arbitrary cross-section on the


basis of indirect data. Thereby, a set of high-precision estima-tions of the averaged flow velocities v(i), i= 1 ... I in I measuringplanes is provided with and high-quality determination on it’s ba-sis the total flowrate. It is shown that effective CFD-modeling offluid and gaseous media is an additional powerful tool allowingto obtain analogous, above-mentioned estimations even in thecase when ultrasonic measurements are produced at unstable orperturbed flow conditions, i.e., v=v(x,y) where (x, y) are Carte-sian coordinates in a normal cross-section. The estimation ofthe flow velocity profiles nearby hydraulic resistances of differentkinds is carried out on the first step by using set of Salami basisfunctions. Numerical modeling include, in particular, three inter-related stages: a) flow profile assignment; b) making up set ofprojections of time-of-flight data for an arbitrary rotation angle ofthe measuring system; c) obtaining direct and quadrature volu-metric/mass flowrate estimations. Applied software for effectivemodeling multipath measurements of asymmetric flows suppliedwith an interactive GUI is demonstrated. In addition, strict mathe-matical estimations for the unperturbed flow profile reconstructionerrors are also given.

We. 8:30 Arp 2 Application of psychoacoustics I

Is the Railway Bonus influenced by the Directions of theSound Sources?Hugo Fastl, Markus Fruhmann, Simon AcheAG Technische Akustik, MMK, TU MünchenAt same energy equivalent A-weighted level LAeq, rail noise usu-ally is judged less annoying than road noise. This effect is calledrailway bonus. On the other hand, at same LAeq aircraft noisefrequently is judged more annoying than road noise, an effecttermed aircraft malus. As one reason for the aircraft malus it isoften assumed that sounds which come from above might be par-ticularly frightening. When accepting this argument it should bepossible to reduce the railway bonus by presenting the road noisein front of the subjects, but the rail noise above them. Results ofrelated experiments with original as well as ’neutralized’ soundsare presented and discussed.


Sound-generating Parameters of Starting Electric RailboundVehicles and their Influence on Sound QualityMartin KlemenzInstitute of Technical AcousticsIn recent years, research activities and sound-abatement mea-sures in the field of electric railbound vehicles (e.g. trams, sub-ways and light-rail vehicles) have been mostly concentrated on


rolling noise. On the other hand, some additional noise compo-nents often play an important role especially during the startingprocedure of modern vehicles. Among them, one can point outthe motor in connection with the traction converter apart fromother sources such as the gear. The acoustic optimisation po-tential of this kind of noise, called ’traction noise’, is rather un-known. Therefore, a study is actually carried out concerningsound sources, relevant psychoacoustic quantities and optimi-sation measures of traction noise. In this contribution, a shortoverview of the sound-generating parameters is presented. Thisincludes a classification of motor types, power-electronic devices,and switching sequences. Since traction noise can sound quitedifferently, each classified noise type is also analysed with regardto its influence on psychoacoustic quantities. More detailed dis-cussion about perception of traction noise will be presented inanother paper of this conference.


Sound Quality of Starting Electric Railbound Vehicles - Di-mensions of Hearing and Relevant Psychoacoustic Quanti-tiesMartin KlemenzInstitute of Technical AcousticsIn order to investigate the psychoacoustic optimisation potentialof starting electric railbound vehicles, sound-generating parame-ters have been analysed in the preceding contribution. Before fi-nally varying some of these parameters (e.g. switching-frequencyrandomisation), quantities for psychoacoustic evaluation must bechosen first. However, apart from general psychoacoustic de-scriptors like loudness or sharpness, it cannot be excluded thatsome other, product-specific quantities also have to be consid-ered. In this contribution, it is described how these quantities aredetermined with the help of listening tests. A semantic-differentialapproach with subsequent factorial analysis yields four main di-mensions of hearing. The most important factor which can becalled ’unpleasantness’ is analysed itself in a second experimentby multiple regression. It is assumed that among the predictorsare not only ’classical’ quantities. For example, traction noise isoften composed of characteristic musical intervals, so that a de-tailed analysis is carried out if consonance plays a relevant roleand if roughness is an appropriate predictor. Finally, the use ofthese quantities for optimisation studies will be outlined.



Sound quality of impulsive noises in interior noises of carsPeter DanielCORTEX INSTRUMENTS GmbHWeak impulsive components may deteriorate significantly thesound quality of interior noises of cars. Especially near thethreshold of hearing, as for example in modern diesel enginessounds, the correct measurement poses high demands on theused instrumentation. Clearly audible impulses, as for examplein closure sounds like door slam noises, are in addition essen-tial for the perception of the quality of the closing mechanism. Itis known for example that low frequency contents of impulsivenoises are associated with high quality and multiple impacts con-tribute to annoyance and higher sharpness is associated withcheaper quality. All these impulsive components have in com-mon that a correct assessment is not possible without taking intoaccount the time and frequency resolution as well as maskingproperties of the human ear. The results of listening experimentswill be compared with psychoacoustical and conventional mea-sures and an intuitive method will be presented to design targetsounds.


Annoyance and loudness of pure tones in noise: applicationto active control of fan noiseSabine Meunier, Guy Rabau, Emmanuel FriotLMA CNRSThe aim of the work reported here is to study the perception ofhissing or booming in noise. These kinds of noises are known tobe very annoying. They are composed of a background noise, towhich a pure-tone signal is added. If the frequency of the puretone is high, a hissing is heard , if it is low, a booming is heard.Many studies have been done on the perception of pure tones innoise, especially by R. Hellman and by H. Fastl and his team forapplications. In this paper we will focus on a particular applicationwhich is active noise control of aircraft fan noise. In the study, thefan noise was composed of a pure tone at around 1.8 kHz witha high level, in a broad band noise, with weaker pure-tone com-ponents at other frequencies. By active control, the peak at 1.8kHz can be eliminated. First, we made experiments to quantifyannoyance in different cases : 1- different sounds were synthe-sized that were composed of pure tones of different frequenciesadded to a white noise. 2- a sound was synthesized that wascomposed of a pure tone at 1.8 kHz added to a low-pass noise.3- noises were recorded on a fan engine in a groundtest facility


with and without control. Secondly, the perceptual benefit of thecontrol has been evaluated. In the end, the perceptual mecha-nisms involved when listening to hissing or booming sounds arestudied in terms of masking and masked loudness.


Evaluation of sound quality affected by tonal components inJapan and GermanyHans Hansen, Reinhard Weber, Takanori Matsui, SonokoKuwano, Seiichiro NambaCarl von Ossietzky Universität OldenburgExperiments were conducted in Japan and Germany concerningthe effect of tonal components on sounds quality. The Japaneseresults were the following: (1) Three factors were extracted byfactor analysis: ”pleasant”, ”metallic” and ”powerful”. (2) The”pleasant” factor decreases with increasing SPL of tonal com-ponents larger than 21 dB, while the ”metallic” impression in-creases at about 18 dB and the ”powerful” factor at about 18 dB.(3) The simple adding of a second sinusoid with a similar fre-quency and the same SPL has no significant effect on the timbreof the sounds. The effect of the frequency on the ”metallic” factorwas measured, when the frequency was doubled. No significanteffect was found on the ”powerful” factor. (4) A two cluster so-lution is obtained by cluster analysis. The sounds are clusteredaccording to the presence of a large tonal component or not. Thegreater the difference in frequency becomes, the earlier can thesound be found in the ”tonal” cluster. These Japanese findingswill be compared to the evaluation of German subjects.


On the pitch strength of harmonic complex tones and comb-filter noisesMarkus FruhmannAG Technische Akustik, MMK, TU MünchenCombfilter-Noises, produced e.g. by filtering white noise by ofa series of FIR-filters, evoke harmonic spectra. Characteristicfeatures for these sounds are the delay time and damping fac-tor used for the delay branch and also the number of filterstepsused to generate the signal. The perceived pitch is compara-ble to the pitch of a harmonic complex tone with components atmultiples of the inverted delay time of the FIR-filter. The pitchstrength of these sounds is very much depending on the numberof filtersteps (iterations) used in the generation process. Comb-filter noise produced by only one filterstep evokes a very weakpeak and thus a very low pitch strength. Using one and the same


filter several times, a so called iterated rippled noise (IRN) is pro-duced, and its pitch strength grows with an increasing number ofiterations. In listening experiments, the pitch strength of iteratedrippled noises and harmonic complex tones was compared usingthe method of magnitute estimation with an anchorsound. Theexperimental results show an expected dependency on the num-ber of iterations. Additionally a strong dependency of the resultson the used delay time (2, 4 and 8 msec corresponding to 500,250 and 125 Hz) was found. In the talk, the experimental resultsare presented. Additionally, the reasons for the dependencies ofthe present data are discussed in the context of pitch strengthdata from the literature.


Comparison of listening test methods : a case studyEtienne Parizet, Nacer Hamzaoui, Guillaume SabatiéLab. Vibrations Acoustique, INSA Lyon - Bât. 303The goal of this study was to compare various listening test meth-ods in the particular case of nine in-car ventilation noises. Sixlistening tests were conducted : - absolute evaluation of noisepleasantness; - evaluation of pleasantness, during which the sub-ject could hear all noises as often as necessary; - pair compar-isons (forced choice procedure); - pair comparisons (five levelsscale); - pair comparisons (continuous scale); - similarity rat-ings, analysed with a multidimensional scaling method (Indscal).These six tests were realised by 64 subjects. Different items wereexamined for each test : its perceived and real duration, its esti-mated difficulty, the accuracy of merit scores attributed to noises,the perceptual spaces which could be built and the accuracy ofa pleasantness indicator which computed from the results. It ap-peared that : - the second procedure can propose a good com-promise between the accuracy of the results and the time neededfor subjects to realise the test. Thus, it can be recommended formany industrial purposes; - perceptual spaces built from the paircomparison tests and the similarity rating one were similar, indi-cating a great stability of sound features used by listeners, what-ever their task; - the MDS analysis of the similarity ratings lead tothe more accurate pleasantness indicator.


On the Use of Psychoacoustical and Psychophysical Meth-ods to Predict Consumer Preference for Interior Car SoundsDaniel Västfjäll, Anders Sköld, Mendel KleinerDepartment of Applied Acoustics, Chalmers Univ of TechWhen designing for product sound quality, it is important to pre-dict consumer preference since making consumer investigations


time consuming. One way of assessing this is by correlating met-rics for sound character with preference data from consumers.The sound character can be assessed in a number of ways. Inthe present research expert listeners were used to retrieve psy-chological dimensions. This was done by a listening test of thewhere the subjects were to rate the sounds on number of uni-polar adjective scales. The results were analysed ANOVAs andPCA, and resulted in five reliable dimensions, explaining 79% ofthe variance. Consumer preference was mapped by a pairedcomparison test design where listeners were to decide which ofthe sounds in each pair they prefer. This data was here analysedwith the Bradley-Terry Luce model (BTL), which resulted in merit-scores for the sounds included. To get a good overview of theperceptual space present for the sounds in the test, expert listen-ers were asked to rate the difference between the sounds, whichwas done in a half matrix design. The data was analysed withan MDS-procedure that resulted in three dimensions explaining97% of the variance present. When the correlation is calculatedbetween the position of the sounds in the perceptual space andthe rating in the psychological dimensions, one gets vector rep-resentation for the psychological dimensions. If the same thingis done for the preference merit scores, one gets a very clearpicture of what dimensions and psychological properties of thestimuli are important for the consumer preference.


A method to assess the ecological validity of laboratory-recorded car horn soundsGuillaume Lemaitre, Patrick Susini, Suzanne Winsberg, StephenMcadamsIRCAMA method is presented which explores the ecological validity of acorpus of car horn sounds, based on the perceided dissimilaritiesbetween these sounds. A car horn is a self-oscillating electroa-coustical device, the sound of which is strongly influenced by itsfixation to the body of the car. The usual procedure to record ahorn is to fix it on a heavy metal bar. But the sound emitted by thishorn-bar device may be fairly different from the sound perceivedon the road. Hence the question arises, ’can the conclusionsdrawn from experimental studies using these recorded soundsbe generalized to real-life situations?”. To answer this question, amethod is designed, which combines qualitive representation ofthe data with quantitative statistical tests. Car horn sounds wererecorded in two ways: three horns were either fixed to the bodiesof two different cars, or were fixed to a standard metal bar andrecorded in three positions. Dissimilarity ratings were obtained


from listeners. Multidimensional scaling was used to assess theinfluence of the fixation on the structure of the dissimilarities per-ceived between the different horns. This representation leadsus to conclude that the dissimilarities perceived among a set ofhorns for a given fixation are independent of the fixation and ofthe position of recording. This assumption is verified by means ofa contrasted analysis of variance. The results of this study allowconclusions drawn from dissimilarity ratings between laboratoryrecorded sounds to be generalized to the real-life cases.


Impact of Office Noise, Irrelevant Speech and Music onShort-Term Memory PerformanceSabine Schlittmeier, Jürgen HellbrückCatholic University of Eichstaett - IngolstadtVerbal short-term memory performance is impaired by irrele-vant background sound so far as the irrelevant speech and non-speech sounds are characterized by distinct temporal-spectralvariations (e.g. narration, instrumental music with prominentstaccato passages). This empirical robust effect is well-knownas Irrelevant Sound Effect (ISE). It has practical implications forworkplaces such as open-plan offices, call-centers and class-rooms. At such places people have to conduct mental work inambient speech noise or office noise (telephone ringing, printernoise and so) which often shows temporal and spectral varia-tions. In our contribution we present results of several experi-ments which investigate impacts of such noise on a memory spantask. In the first series of experiments we were able to show,that memory span of visually presented digits is significantly dis-rupted by background speech as well as by instrumental staccatomusic, but not by legato music and pink noise. In additional ex-periments we found the same results for the memory span ofauditorily presented items, although these items were presentedin a signal-to-noise ratio which allowed perfect intelligibility. Ina third series of experiments, we investigated the effect of officenoise including speech, telephone ringing and other typical open-plan office sounds on memory span for visually and auditorilypresented items as well. Our results demonstrate that the detri-mental effects of untreated office noise on short-term memoryperformance can be reduced by superimposing the office noisewith pink noise or instrumental legato music.



Psychoacoustic investigations on the efficiency of a vehi-cles’ encapsulation in the underbody areaChristine Patsouras, Klaus Pfaffelhuber, Dimitrios Patsouras,Herbert Finsterhölzl, Michael Birnkammer, Rene SchönfelderAKsys GmbHAs described in former investigations (Patsouras D. et al. Daga2003) with new concepts of passive measures in a vehicles’ un-derbody area good improvements can be obtained for the out-door idling noise of Diesel powered cars. These concepts wererealized by means of an upper middle class car. The differencesin level reached by those measures served in the following as fil-ter functions to simulate the measures for further outdoor idlingnoises. In particular for the power-enhanced version of this ve-hicle the possibilities of sound quality enhancements by passivemeasures should be studied in this way by means of psychoa-coustic experiments. It appeared that in case of a consequent re-alization of the concept the sound quality of the power-enhancedversion can actually get ahead of the sound quality of the stan-dard one.


Application of a psychoacoustic model for the determinationof the psychoacoustic roughness of interior car soundsCarsten Zerbs, Otto MartnerMüller-BBM GmbHBesides the design and the optical appearance of a car also theinterior sound is important for its perceived character. In orderto quantify and to characterize the different factors contributingto the sound perception of a car and to explore the differences inthe perceived image between listeners originating from a differentorigin, a hearing test was designed and carried out in Central Eu-rope and North America. Test sounds from three driving modeshad to be compared according to 12 different attributes within apaired tournament test. Altogether, 71 test subjects took part inthe test. Test results were checked for concordance and interindi-vidual reliability. A factor analysis (PCA) was performed on theaverage scale values within one driving condition. A comparisonof subjective judgements and objective psychoacoustic param-eters showed that the correlation between subjective roughnessand the objective roughness was quite poor. A recently presentedmodel (DAGA 2001), which considers the order structure of carsound, was employed to improve the correlation between subjec-tive and objective psychoacoustic roughness.



Perception of sound emitted by vacuum CleanersJérémie Brocard, Etienne ParizetLab. Vibrations Acoustique, INSA Lyon - Bât. 303The noise emitted by an object is a source of objective and sub-jective information. For instance, it is a way to know whetherthe system can correctly work or not (objective information) andto estimate its quality (subjective information). In the particularcase of the vacuum cleaner, it is important to keep the subjectiveinformation related to the impression of power, and to minimizethe annoyance linked to different criteria (sound pressure level,sharpnessoe) The purpose of these perceptive tests is to deter-mine how listeners assess the impression of both the efficiencyand annoyance of sounds in vacuum cleaners. A preliminary ses-sion of listening tests has shown that each of the 8 models of vac-uum cleaners has its own tone. The position of the dummy headdoes not seem to influence the tone very much during the record-ing. Consequently, the recording position does not generate anyconfusion between different models, one position is freely cho-sen for all recordings. The task of each of the 61 subjects (aged25 to 65) is to supply an estimation of both the annoyance andefficiency impression during the session of perceptive tests thatfollows. It is to be done on an absolute scale. The whole groupcan be divided into two sub-groups having their own estimationstrategies on the impression of efficiency.


Application of psychoacoustical models for speech intelligi-bility predictionBirger Kollmeier, Thomas Brand, Kirsten Wagener, RainerBeutelmannMedizinische PhysikHearing-Impaired listeners have tremendous communicationproblems in a cocktail party situation.This talk will review currentmodels that predict cocktail party performance in normal listenersand also describe the degradation of performance in sensorineu-rally hearing-impaired listeners. The models can be validated bycomparing human performance with numerical model predictionsof auditory perception for normal and hearing-impaired listenersand with computer speech recognition.A good approximation ofhuman auditory performance in cocktail parties seems to be anadaptive two- microphone array with a lossy dynamic compres-sion followed by an optimum detector. A straight-forward imple-mentation of this idea is the model by v. Hövel (1984) which


has recently been updated and applied to more complex acous-tic situations in our lab. It employs a filterbank with independentEqualization- and Cancellation mechanisms in each frequencyband that are numerically adjusted to optimize the signal-to-noiseratio at the output. Another important issue is the prediction ofspeech intelligibility in fluctuating noise as a function of the in-dividual’sspeech reception threshold in quiet and in stationarynoise (Wagener, 2003): The best prediction of human perfor-mance is obtained with a two-stage model of sentence recog-nition, where in a first stage the individual subunits of each wordis perceived with a certain error probability. In a second stage,the recognized items are combined in a more or less faulty wayto form the complete recognized words and sentences.


An Auditory Model for Coding Speech into Nerve-Action Po-tentialsMarcus Holmberg, Werner HemmertInfineon Technologies AGInformation coded within the spike-trains of auditory nerve fibresprovides the basis for spectral, temporal, and spatial informationprocessing at higher levels in the auditory pathway. Here wepresent an auditory model that codes audio signals into actionpotentials. A wave-digital filter models the inner ear and providesspectral decomposition. A phenomenological model of the ac-tive amplification of the outer hair cells compresses the dynamicrange up to 80 dB, while matching the level-dependent shape ofthe active inner ear filters. Fluid forces, derived from basilar mem-brane displacement, deflect the inner hair cell (IHC) stereociliarybundle. The deflection opens ion channels and the resulting cur-rent triggers an IHC receptor potential, which in turn activatesvoltage-dependent calcium channels. The intracellular calciumconcentration controls the fusion probability of vesicles close tothe synapses. Fusing vesicles release neurotransmitter, whichelicits action potentials in the auditory nerve fibre (ANF). Adap-tation is caused by depletion of a pool of vesicles in the vicinityof the synapses (ready releasable pool) and ANF refractoriness.Tests with voiced speech show that formants, but not individ-ual frequency components, are resolved in the ANF spike-trains.The representation conserves periodicity in the form of ampli-tude modulation with the fundamental frequency. Thus speechsounds are coded into a spatio-temporal pattern rather than apure frequency-place code. The additional temporal informationis thought to be important for speech intelligibility in noisy andreverberant environments.



Psychoacoustics in Audiology: applications for diagnosisand treatment of hearing disordersUwe BaumannLMU München/Klinikum Großhadern/HNO/AudiologieOne of the most important domains of applied psychoacoustic isthe area of audiology. A wide variety of applications of psychoa-coustical methods are employed to assess auditory dysfunctionsas well as to achieve a satisfying fit of hearing aids or cochlearimplants. The presentation will give an overview over basic audi-ological tools in use for differential diagnosis of hearing disordersand also address advanced methods such as loudness scaling oradaptive procedures to measure speech perception in quiet andin noise. Another important application of psychoacoustics canbe found in the area of audiological research. As an example,some of our recently obtained results concerning pitch discrimi-nation and sound quality estimations with cochlear implants willbe presented.


Finite Difference Time Domain Simulation of the Outer EarSebastian Schmidt, Herbert HuddeInstitut für Kommunikationsakustik (Web: www.rub.de/ika)The examination of sound field problems by using finite or bound-ary element calculations is well established. Usually a harmonicanalysis is performed; for each frequency of interest a completesolution of the equation system is done. If systems having shortacoustic impulse responses are to be investigated, time-domaincalculations can be expected to be more efficient because com-plete frequency responses are obtained from a single impulseresponse calculation by taking the inverse Fourier Transform. Inthis project a finite difference time domain (FDTD) approach withcentered grids is applied to wave propagation problems concern-ing the outer ear. This general class of FDTD formulations leadsto fast algorithms. The model yields time functions of acousticvariables by straightforward discretisation of the wave equation.For each time step the evolution of the values is calculated atevery node in the centered grids. In further processing stagestransfer functions, radiation impedances, or chain matrix param-eters are derived from the calculated results. The fundamentalformulation of the model is based on orthogonal grids. It turnedout that the accuracy can be impaired when irregular boundariesoccur or if boundaries are inclined referred to the grid. To im-prove the accuracy voronoi cells are used near the boundaries.


This technique avoids the wave retardation observed for stair-case boundaries. The current set of geometrical models includesvarious ear canals and natural and artificial (dummy head) pin-nae. Results of ear canal calculations are shown, and the ac-curateness of the results is examined for different grid configura-tions.


Hörgeräte mit verschiedenen Regel-Zeiten bei Ver-ständlichkeitsuntersuchungenEdward Hojan, Dorota Hojan-Jezierska, Hugo FastlInstitut für Akustik Adam Mickiewicz UniversitätBemerkenswert ist, das die getragene Hörgeräte, bei Schwer-hörigen noch vorhandene - normale Gehöreigenschaften, ver-schlechtern können; es ist zu vermuten das es sich hier von allenum Zeitauflösungsvermögen handelt. Es wird zu überprüfensein, in wie weit diese Verschlechterung des Zeitauflösungsfak-tors einhergeht und welche Sprachverständlichheit von Schw-erhörigen Personen, insbesondere bei Verwendung von Hörg-eräten mit einstellbaren Stell - und Regelschaltungen, erzielt wer-den kann.


Significance of Meaning in Sound Quality EvaluationAlfred Zeitler, Wolfgang Ellermeier, Hugo FastlSound Quality Research Unit, Dept. of AcousticsThere is wide agreement that perceptually-adequate sound eval-uation has to encompass not only the sensory domain but alsocognitive and emotional aspects of the auditory event. In par-ticular, the meaning of a sound has been identified as an im-portant factor in sound quality evaluation. The current investiga-tion inquires into the significance of this factor for sound-qualityjudgements of various environmental and product sounds using anew signal-processing method which reduces the identifiability ofsound sources substantially while preserving the loudness-timefunction [H. Fastl, ICA, Rome, 2001]. In contrast to a previousinvestigation [A. Zeitler, J. Hellbrueck & H. Fastl, DAGA 2003]that focussed on the effect of this type of signal processing onperceived loudness, the present study investigated the issue forperceived annoyance as well. In the first part of the experiment,four independent groups of subjects (N=25 each) responded oncategory-subdivision scales of loudness or annoyance to eitherthe original or processed version of the signals. In the secondpart, subjects provided ratings of the stimuli on a concept-specificSemantic Differential. Results include analyses of the impact ofsource identifiability on loudness and annoyance judgements as


well as an investigation of these effects in terms of differences inthe semantic profiles elicited by the sounds.

We. 8:30 Arp 3 Environmental noise and machinery noise II

Acoustic-signature-based determination of railway vehiculespeed - application to tramwaysGuillaume DutilleuxLaboratoire Régional des Ponts et ChausséesWhen characterizing the acoustic emission of transport ve-hicules, acoustic parameters must be linked with kinematics andspeed in particular. Speed is usually obtained from a radar de-vice. Unfortunately, the standard devices tend to be unreliablebelow 30 km/h. It is shown in the present paper that, in thecase of railway vehicule, speed information can be recoveredfrom a pass-by acoustic recording taken close to the axis theinvestigated vehicule moves along. This is made possible by thefact that events in the signature gives unambiguous spatial in-formations. The computation of speed is performed on short Leqtime series. Different elaborate post-processings are considered.One is based on auto-correlation of the Leq signature that filtersout parasitic signature irregularities. The other adopts a patternmatching approach. It involves a simple model of the acousticsignature. On experimental data, the first method gives goodresults but appears to be somewhat operator-dependent. Thepattern matching approach proves to be more robust, althoughmore time-consuming, due to the iterative matching process.


Investigations into the Prediction of Construction NoiseUwe Trautmann, Matthias PötterAIT Ingenieurbüro Dr. Trautmann GmbHResidents are often exposed to a considerable noise impactfrom inner-city building sites. To shorten construction times, re-duce construction costs and perform technologically indispens-able works, there is always an interest in performing buildingwork even during resting hours. Construction-noise predictionprovides the basis for a special permit to be granted by the com-petent authority. New investigations are presented, which allowto improve the agreement between predicted and measured rat-ing levels by considering in detail the different times of use of theindividual machines.



Distribution Relations of Sound Emission, Propagation andImmission and Effects on the Uncertainty of Sound Immis-sion Calculation and MeasurementAlois HeißBayerisches Staatsministerium für Umwelt, Gesundheit und Ver-braucherschutzBy currently valid standards in the field of sound impact assess-ment there is an increasingly demand for quality management. Inthis context the sound level distributions are important elementsas the uncertainty of descriptors taken for prognosis or mea-surement of sound immissions are determined significantly bythe structure of their probability distributions. This is reason thatthe available discussion papers on this topic are supplementedby a quite systematic resume of the distibution interactions ofemission and propagation. Based on the distributions as for theemission as for the attenuation on propagation path, the soundlevel distribution created at immission site is here described ex-plicitely in a quite general manner and is illustrated by representa-tive calculations. The distributions used are founded on physicalreasons and on common measurement experience. This proce-dure allows to examine easily the quite frequently claimed nor-mal distribution in sound pressure level space on its probably stilltolerable deviations from reality. This is of interest because theacceptance of a strict normal distribution hypothesis seems tobe inadequate: The superposition of two normal sound pressurelevel distributions runs in intensity space and for this reason theresulting distribution cannot exactly be a normal distribution. Theaspects following from this for acceptable approximations in theassessment practice are outlined. In addition, for presentation ofthe uncertainty of energy equivalent mean levels based on smallsamples, especially from very assymmetric parametric intensitydistributions, a computer based bootstrap procedure, without us-ing the variance by common definition, will be discussed.


Correlation of sound pressure squared and sound intensitysignals investigated for different positions of a measure-ment surface in the field of sound sourcesGerhard Hübner, David KandelakiUniversität StuttgartThe sound power of technical sound sources such as machinesor equipment can be determined by measurements of the timeaveraged sound pressure squared or respectively by the sound


intensity both taken over a surface enveloping the source usu-ally taken at N discrete measurement positions. From these datathe spatial mean values pressure squared respectively the spa-tial mean intensity are to be calculated where the ”quality” of thismean value and simultaneously that of the yielded sound powerdepends from the number N of these positions for a given soundfield situation. Describing this ”quality” by a certain span of its un-certainty the question arise how many positions N are necessaryto fulfill a certain given accuracy requirement. A relevant rule forthis determination issued by relevant ISO-Standards is based onstatistical rules assuming non-correlated signals of the measuredquantities. The paper presents results both of experimental andtheoretical correlation investigations, where the objects for thesound pressure measurements are sources radiating structureborne and airborne noise. The theoretical investigations are fo-cused as well as on sound pressure squared and intensity soundfields generated by baffled plates in ”usual” measurement dis-tances. This investigation is a first step for establishing a rule forthe determination of number of measurement positions N guar-anteeing a sound power value within a certain limit of uncertaintyfor practical situations.


German Calculation Procedure for Aircraft Noise ExposureHeinz-Dieter Marohn, Thomas MyckUmweltbundesamt BerlinGerman Calculation Procedure for Aircraft Noise ExposureHeinz-Dieter Marohn, Thomas Myck Federal EnvironmentAgency Berlin In 2002 the European Parliament and the Counciladopted the Directive on Environmental Noise. According to thisDirective common noise indices (Lden and Lnight) must be usedfor the production of strategic noise maps. The European Com-mission strives for common methods for determination of theseindices. Due to the fact that common methods are not availableat present the directive contains interim computation methods fordifferent noise sources. For aircraft noise the European Commis-sion recommends an interim computation method which is pri-marily based on ECAC.CEAC Document 29 and is completed insome points. Until the use of common assessment methods forthe determination of Lden and Lnight is made obligatory, Mem-ber States may use their own noise computation methods. Theresults of the chosen national computation method have to beequivalent with those of the interim method. Germany intends touse modified national noise calculation procedures. In the fieldof air traffic it is planned to adapt the national instructions for thecalculation of noise protection areas (”AzB”) to the requirements


of the Directive. This comprises in particular the adoption of Ldenand Lnight as well as the proof of the equivalence of the results.The modified AzB calculation procedure corresponds largely tothe interim aircraft noise calculation method and goes partiallybeyond it. For these reasons no difficult problems in demonstrat-ing the equivalence of the results are expected.


Sound Power of Construction Machines: Declared Values vs.In-Situ MeasurementsUwe Trautmann, Meike PetersAIT Ingenieurbüro Dr. Trautmann GmbHIn accordance with EU Directive 2000/14/EG, construction ma-chines must be labelled with a noise declaration. Furthermore,this directive also specifies limiting values for the maximum per-missible sound power level of various construction machines,which are sometimes difficult to comply with. For selected earth-moving machines, the declared sound power (determined in ac-cordance with the standard) has been compared with that mea-sured in situ in order to - estimate the contribution of the workingprocess to the overall noise and - obtain realistic input data forambient-noise predictions. An attempt is being made at quan-tifying various measurement and operating parameters so as toexplain differences between standard and in-situ measurements.


Auf der Suche nach dem höchsten BeurteilungspegelBerthold VogelsangNLöIn der Auseinandersetzung zwischen Anlagenbetreibern und An-wohner im Rahmen des akustischen Immissionsschutzes wollenalle Beteiligten ihre ’Ruhe’ haben. Die Wege dorthin un-terscheiden sich je nach Interessenslage mitunter erheblich.Während Anlagenbetreiber für beschleunigte Genehmigungsver-fahren oder wenigstens für die Streichung einer Spalte in der4. BImSchV starke Sympathien zeigen, fordern Anwohner ve-hement eine ’worst-case’ Betrachtung bei der Beurteilung derStörwirkung statt der heute festgelegten Mittelung. Dies gilt ins-besondere bei der Genehmigung von Flugplätzen. Die Gerichteunterstützten durchweg die Anwohner in ihrem Anliegen desSchutzes vor einer erheblichen Belästigung: Die Ermittlung derGeräuschbelastung habe auf der ’sicheren Seite’ zu liegen. Sofordert z.B. die TA-Lärm für alle Anlagen in ihrem Anwendungs-bereich, die bestimmungsgemäße Betriebsart zu ermitteln, dieden höchsten Beurteilungspegel erzeugt. Sofern verschiedene


solcher Betriebsarten im Hinblick auf die Lärmbelastung unun-terscheidbar sind, tritt kein Problem auf. Welche Betriebsart istaber einer Genehmigung zugrunde zu legen, wenn die Anlagedeutliche, wetterbedingte Schwankungen aufweist, auf die derAnlagenbetreiber keinen Einfluß hat? Bei Flugplätzen konkurri-eren mehrer Antworten auf diese entscheidende Frage: beispiel-sweise die Berücksichtung nur der 6 verkehrsreichsten Monateim Prognosejahr oder die Verwendung der 100%- Regelungoder die Zugrundelegung der Bahn- oder Umweltkapazität. DerBeitrag entwickelt auf Basis der besonderen Regelungen der TA-Lärm einen einheitlicher Lösungansatz. Dieser Lösungsansatzwird exemplarisch an Windenergieanlagen, Badeanstalten undFlugplätzen vorgestellt und diskutiert.


Zur Wahl des maßgeblichen Immissionsortes unter Berück-sichtigung der Phänomene der BodenreflexionBerthold Vogelsang, Karl-Wilhelm HirschNLöDie Wahl des Messortes für eine Schallimmissionsmessung aberauch die Wahl der Höhe der Immissionspunkte bei der Ermit-tlung von flächenhaften Gerduschbelastungen wird häufig durchpraktische Erwägungen bestimmt. Die in älteren oder auchnoch gültigen Normen niedergelegte Vorschrift, 0,5 m vor demgeöffneten Fenster und oder in 4 m Höhe zu messen, ist einer-seits der Begründung nach (Vermeidung von Gebäudereflexio-nen) schwach, solange es sich um mittlere bzw. tiefe Frequen-zen handelt, andererseits aber auch völlig unpraktisch, da heutemehr Langzeitmessungen gefordert werden, um den gefordertenAussagen zur Qualität der Ergebnisse hinreichend gerecht zuwerden. Bei der Berechnung von Schallimmissionsplänen istes häufig die Rechenzeit und der Dokumentationsaufwand oderdie pauschale Forderung nach Vergleichbarkeit, die die Wahldes Immissionshöhe auf eine einzige Höhe beschränkt. DerVortrag möchte im Hinblick auf die Einflüsse der Bodenreflex-ion aufzeigen, welchen Einfluss die Empfängerhöhe auf den Im-missionspegel haben kann. Dies wird anhand von Messungenund Modellrechnungen exemplarisch an mehreren Beispielenwie Windenergieanlagen, Knallen und Vorbeifahrten bzw. über-flügen dargestellt.



On the Accuracy of Sound Power Determination for a GivenLevel DistributionGustav SehrndtBeratung zur LärmminderungSome investigations of the errors of the machinery sound powerdetermination from either sound pressure or intensity measure-ments are based on the assumption of its independence and ran-dom distribution. It can be shown that the accuracy for a givenlevel distribution depends on the density of microphone positionson the measurement surface related to the other errors.


Die europäische Umweltlärmrichtlinie - Das deutscheBerechnungsverfahren für Lärmbelastung durch die Indus-trieMatthias HintzscheUmweltbundesamt BerlinDie Europäische Kommission ist bei der Umsetzung der eu-ropäischen Umweltlärmrichtlinie auf die Besonderheiten dereinzelnen Staaten eingegangen. So ist es z. B. möglichdie genaue Lage und die Dauer der Beurteilungszeiträumeentsprechend den nationalen Gegebenheiten anzupassen.Liegen nationale Berechungsmethoden zur Ermittlung derBeurteilungspegel bereits vor, können diese nach Anpassungweiter verwendet werden. Im Rahmen dieses Beitrages soll deraktuelle Stand der Umsetzung der europäischen Umweltlärm-richtlinie und die nationalen Besonderheiten im Bereich des In-dustrielärms beschrieben werden.


Optimising Ergonomic and Acoustic Design of Hand-heldSound Level MetersJulian Simpson, Douglas Manvell, Lars Kroman, Helge Larsen,Erling OlsenBrüel & Kjaer Sound and Vibration Measurement A/SHand-held instruments are, by their very nature, used in the handby humans. Genetic mechanisms make sure that all humans andtheir hands are different; not an ideal situation for a hand-held in-strument designer who would prefer clones with the same outlookin life. However, in recognition of the fact that individuality ex-ists, a research group investigated the expectations of potentialand current hand-held instrument users, and the findings wereused to construct a new form of sound level meter (SLM). Thepaper describes how a series of ’Panel of Experts’ workshops


were used to arrive at two central demands from users for hand-held instrument design - robustness (proof against dust, water,humidity etc.) and practicality in all work situations - and howthese demands were used, via physical and mathematical mod-elling tools, as guides to optimise the often conflicting ergonomicdesign and IEC 61672 acoustic performance criteria. This paperalso describes how, through the use of new shapes and mate-rials, an SLM was created to fulfil the design goals to make iteasier, quicker and safer for all user groups to conduct measure-ment assignments.


Low-Noise Circular Saw BladesJürgen Maue, Ralf HertwigBIA - Berufsgenossenschaftliches Institut für ArbeitsschutzThe high noise emissions from circular saws frequently representa major impact in different branches of industry. In many casesthe noise exposure of employees can be reduced substantially byusing low-noise circular saw blades. Until now the low-noise sawblades available on the market have generally been used ratherseldom in industry which possibly can be explained by lack ofinformation. Therefore the BG-Institute for Occupational Safetyand Health has started a project to determine the scope for theuse of low-noise circular saw blades and the potential noise re-ductions, and to develop a manual for noise control of circularsaws suitable for practical application. Based on a market sur-vey of low-noise circular saw blades numerous comparative noisemeasurements were performed under different working condi-tions, cutting wood, aluminium and plastics, both in-plant and inthe laboratory. The first results of this project are presented.


Exigence of Sound Insulation Measures in the Vicinity of Air-ports and Traffic RoutesHeinrich MetzenDataKustik GmbHIn noise mapping projects, the assessment of the noise levels isintended to result in actions to reduce the noise impact for the in-habitants in the investigated area. This aim has already been partof national regulations on noise immission maps and is empha-sised by the EC-directive on Environmental Noise. Possible ac-tions comprise besides traffic and land-use planning, measuresat the sources also the reduction of sound transmission by im-proving the sound insulation of facades of buildings. This objec-tive can be handled by software techniques evaluating the facadelevels and the sound reduction index of the facade elements. For


rough estimations the performance of windows is used to assesswhich buildings in the area need further treatment or even a com-plete reinstallation. When a more detailed study is required thebuilding facade composed of different parts (e.g. facade, window,air intake) can be modelled in detail making use of the outdoorlevel as calculated with the noise mapping software. This proce-dure is quite useful when national building regulations specify amaximum or mean indoor level as performance parameter. Thispaper discusses strategies and techniques focussing on noisemapping projects in the vicinity of airports and traffic routes.


Wind turbines: Statistical parameters characterising noiseemission and noise impactDr. Sergio MartinezTüV RheinlandAccording to TA Lärm (Noise Protection Guidelines according theImmission protection law of Germany) it has to be shown, thatthe noise level of wind energy plants meets the standard limits(TA Lärm) in the neighbourhood e.g. after putting into operationof new wind turbines or increasing the number of plants of a windpark. Therefore noise measurements will be made close to theplants and the noise power level calculated (emission measure-ments). With the (in situ) measured noise power level the ratedlevels at the impact points will be calculated. Direct measure-ments of the noise impact levels mostly turn out to be difficultbecause of the high wind velocities near the ground required forthe rated power. Additionally it cant be required to measure thesound impact. These measurements should be made simultane-ously to the emission measurements. The difficult measurementconditions necessarily lead to higher measurement uncertainties.A sufficient time window has to be provided were the wind tur-bines are completely switched-off. The measurement task can bestatistically attributed to an inversion of the (mathematical) con-volution of connected distributions. The wind turbines-specificdistribution of noise emission and impact can be approximatelyreconstructed and the characteristic quantities of noise emissionand impact can be derived.


Akustische Linsen, Einsatz als offene Lärmschutzwände? -Untersuchungen an Modell-Linsen -Michael ChudallaBundesanstalt für StraßenwesenIn der Halle für akustische Modelltechnik der Bundesanstalt fürStraßenwesen wurden Messungen an im Maßstab 1:8 linear


aufgebauten akustischen Linsen (Umweglinsen) durchgeführt.Umweglinsen bestehen aus schräg zur Ausbreitungsrichtungangeordneten Lamellen unterschiedlicher Länge. Untersuchtwurde die Lage der Brennpunkte verschiedener Frequenzen unddie Abstrahlcharakteristik bei zwei unterschiedlichen Abständenzwischen Schallquelle und Linse. An den untersuchten Linsenwurden die Lamellenwinkel und -abstände (Anzahl an Lamellen)variiert. Es wird über erste Erfahrungswerte berichtet, ob ein Ein-satz solcher Linsenaufbauten als offene Lärmschutzwände oderAufsätze auf Lärmschutzwände möglich sein könnte.


Aircraft Noise Annoyance at 5 German AirportsJoachim KastkaUniversität DuesseldorfNoise Annoyance Reactions to Aircraft Noise of 6746 Residentsat 5 German Airports (Frankfurt, Düsseldorf, München, Köln,Hamburg) were sampled by standardized Telephon-Interview-Technique at 220 sample points beween 1985 und 2001. Aircraft-Noise-Immission-Data (Leq3_Day , Leq3_Night, NAT70_day,NAT70_night) of the sample points were computed by Noise-Immission-software CADNA and Data of Aircraft Movementsdefinded by the DES (Datenerfassungssystem) of the AirportAuthorities.The Data give the impression of a general Dose-Response-Relation forr most of the Airports. Time of Day,Indoor/Outdoor Position of Resident and Position of Windows(Open/closed) are importand determinants of the Global Annoy-ance Reaction Results lead to the conclusion, that global annoy-ance is a rather indifferent and in some case misleading con-cept. Data analysis revealed a number of problems using the28% cut_off for the defintion of Highly-Annoyed-Criteria Schultz),which seems to suffer under a proper conceptual background.

We. 17:10 Arp 3 Wave field synthesis I

Spatial Perception in WFS Rendered Sound FieldsGünther TheileInstitut für RundfunktechnikModern convolution technologies offer possibilities to overcomeprinciple shortcomings of loudspeaker stereophony by exploit-ing the well-known Wave Field Synthesis (WFS) concept for ren-dering virtual spatial characteristics of sound events. Based onthe Huygens principle loudspeaker arrays are reproducing a syn-thetic sound field around the listener, whereby the dry audio sig-nal is combined with information about the room and the source’sposition to enable the accurate reproduction of the source withinits acoustical environment. Recent developments have shown


that a number of applications could be possible in the near fu-ture. However, they have also shown that basic and practicalconstraints of WFS systems limit the rendering accurateness andthe perceived spatial audio quality to a certain degree, dependenton characteristic features and technical parameters of the soundfield synthesis, such as spatial aliasing, effect of reflections ofthe reproduction room, restriction to the horizontal plane, limita-tion of array dimensions (diffraction effect), occlusion effects, etc.Psychoacoustic studies are necessary to evaluate the resultingimpacts on attributes of spatial perception not only with respectto the development of WFS systems but also in view of scien-tific knowledge. Particular attention should be turned to the per-ception of direction, distance, spatial depth, spatial perspective,spatial impression, reverberance, and envelopment. The follow-ing papers in this structured session will highlight some of theseaspects and already provide preliminary conclusions on the pos-sibilities and limits of WFS applications.

We. 17:30 Arp 3 Wave field synthesis I

On the Audibility of Spatial Reflection Changes in Relationto WFSMarinus Boone, Hiske HellemanDelft University of Technology, Laboratory of Acoustic Imagingand Sound ControlThe WFS-principle is very well suited for sound rendering over alarge listening area without the limitations by a sweet spot. Evenwith the simplification of using line arrays of loudspeakers, theresulting 2.5-D solution gives reliable results in many situations.Source directions are maintained correctly as a result of the ac-curate wave front and distance perception by the addition of spa-tially correct reflection and reverberation patterns. In relation tothe latter an important question is how accurate the recordingor synthesis of spatial reflections and reverberation must be fora perceptual transparent reproduction with WFS. A preliminarystudy has been carried out to find the threshold of audibility ofspatial variations in the position of a single reflection. It was foundthat the minimum audible distance variation of a single reflectionis 1 - 2 m, or 5 - 10 degrees, depending on the spatial config-uration, and whichever is the largest. From that result prelimi-nary conclusions can be drawn about the necessary resolution inrecording and synthesis of reflection patterns for WFS rendering.


Th. 8:30 Schweitzer Silencers

Acoustic Properties of Aluminium Foams - Measurementsand ModellingWaldemar Maysenhölder, Andrea Berg, Philip LeistnerFraunhofer Institut BauphysikThe cylindrical aluminium-foam samples investigated are the re-sult of a high-pressure die-casting process around a sinteredpolymer-granulate compact. These porous materials possessa porosity around 60% and specific flow resistance between 3and 10 kPas/m2. Sound absorption and transmission at normalincidence and the insertion loss of a silencer have been mea-sured. Two theoretical models - a corrected and extended ver-sion of the model of Lu, Chen and He and the variants ’Simpli-fied’ and ’Extended’ of Wilson’s model - have been used for fittingand analysing the experimental data. The agreement with someabsorption measurements is quite satisfactory with both models.However, Wilson’s model, which has some advantages in generaland also in particular with respect to porosity and flow resistance,is preferred. It helped to explain the orientation dependence ofthe absorption as an effect of a slight inhomogeneity of the sam-ples. Its validity has been further checked against absorptionmeasurements with an empty cavity behind the sample. Approxi-mate empirical relationships between the fitted model parametersand the measured properties porosity and flow resistance mayserve as a (preliminary) prediction tool. Finally, calculated trans-mission and insertion losses obtained with the previously fittedmodel parameters are discussed.


Panel resonator and slot absorber silencers for low and midfrequenciesRobert Hanisch, Norbert Rambausek, Peter BrandstättFraunhofer Institut BauphysikNew resonance type silencers designed for the low and mid fre-quency range in industrial applications as splitters and duct lin-ings are presented. The silencers are characterized by their slimbody with low pressure loss and good protection against exhaustair impacts. Working principle, application examples and inser-tion loss measurements are presented verifying the enhancedperformance in the frequency range of interest.



Noise reduction at heating system exhaust pipesPeter Brandstätt, Karlheinz Bay, Günther FischerFraunhofer Institut BauphysikNew burner technologies in house heating systems and powerstations have increased the efficiency of gas and oil consump-tion but also led to an increase of the noise levels in the exhaustpipes, mainly in the low and mid frequency range. As new reg-ulations for noise in the neighborhood are discussed, silencersgain increasing importance. The paper will present the work-ing principle of various new silencer developments together withmeasurements and installation examples at existing systems.


Rohrschalldämpfer mit ovalen und rechteckigenQuerrschnittenUlrich Ackermann, David Bergand, Christian MüllerFachhochschule SüdwetfalenRohrschalldämpfer mit ovalen und rechteckigen Querschnit-ten lassen sich besser in flache Kanäle einbauen. DieseSchalldämpfer lassen sich aber nur dann preisgünstig herstellen,wenn sie aus runden Rohren gedrückt werden können. Alu-minium als Werkstoff reißt aber beim Drücken leicht. DieRohrschalldämpfer wurden deshalb nicht nur akustisch optimiert,sondern auch fertigungstechnisch.


’Surface radiated noise from exhaust systems - StructuralTransmission Loss test rig’Jan Brand, Dirk WiemelerTenneco Automotive, Heinrich Gillet GmbH, Acoustics Compe-tence CenterThe sound radiation from exhaust systems can be divided intothree categories: The tailpipe noise, the noise transmittedthrough the hanger and the surface radiated noise. The radiationfrom the tailpipe influences the pass-by test as well as the radia-tion from other sources like the engine and the wheels. The sur-face radiated noise and the noise transferred through the hangergenerally do not influence the pass-by test but they representa subjective noise problem. Measurements of surface radiatednoise from exhaust systems currently require two rooms: one toisolate the engine against the exhaust system, and another, ananechoic chamber, to measure the radiated noise. The resultsare the radiated sound pressure or the sound power. These re-sults depend on the noise source as well as on the geometry of


the surroundings. This paper deals with an innovative measure-ment procedure for radiated sound power which is independent ofthe geometry of the surroundings and the source. The measure-ment still requires an anechoic chamber but no extra facilities tohouse an engine. A simple speaker serves as the noise source.The measurement result is a transfer function of the structure.Noise mapping is possible as well as the calculation of the modaldamping. Using this test rig it is also possible to separate air res-onances from structural resonances. This test rig is not meant toreplace the acoustics engine test rig, but to complement it.


A Single-Run Method to Evaluate Sets of Mode Solutions inLined DuctsFridolin MechelF.P. MechelThe sound field eva1uation in lined ducts by moda1 ana1ysis re-quires solutions of the characteristic equation for the mode prop-agation constants of a set of modes (mode solutions). They mustbe · precise (i.e. nulling the characteristic equation-down to asmall magnitude), · complete (i.e. no solution missing in a fi-nite set), · unambiguous (i.e. no solution appearing repeatedly).Existing methods need ’starters’ (approximate solutions) for thenumerica1 solution of transcendental, complex equations. Thestarters must be a set of a1ready rather precise, and completeapproximations, otherwise the equation solver risks to jump tounwanted solutions. Existing methods eva1uate one mode so-lution in one run. The proposed method is based on the fact,that the transcendental functions in the characteristic equationsfor modes in lined ducts can be expanded as continued-fractionswith the square z2 of the wanted wave number as argument. Thecontinued-fraction representation converges in the whole com-plex plane of z , except in poles on the rea1 axis (which belong tomodes in soft-wa1led ducts ). Terminating the continued-fractionat a finite depth of expansion, and collecting in a fraction with acommon numerator N(z2) and denominator D(z2) will transformthe characteristic equation to a polynomia1 equation in z2 . Thesolution of polynomia1 equations, even of high degree (z2)n ,is a standard task of numerica1 mathematics. The set of modesolutions can be identified by simple criteria in the larger set ofpolynomia1 solutions.



Calculation of Silencer with Circular Cross Section and Cen-tre BodyUlrich KurzeMüller-BBM GmbHBased on broad experience many computer programmes areavailable for the design of silencers. The more precise determi-nation of the effects of dimensions, materials and operating con-ditions requires the solution of the wave equations with boundaryconditions for sound absorbing walls. The simple geometry ofa circular silencer results in Bessel functions, which contain thepropagation constant in implicit form. Methods for determiningexplicit solutions have been the subject of various investigationsover the last decades. Special problems arise when the flow pro-file shall be considered and - as for tubular silencers with centrebody - when the boundary conditions are non-symmetrical. Ex-tending former investigations on rectangular ducts, potentials aredescribed resulting from the solution of finite difference - ratherthan differential - equations for four points in the cross sectionof the flow duct. Results obtained from such calculations arecompared with those from other calculation procedures and frommeasurements.

Th. 13:50 Schweitzer Audiovisual interaction

Detecting and Using Temporal Correlations between Ran-dom Sequences of Auditory and Visual EventsArmin Kohlrausch, Steven Van De ParPhilips Research EindhovenIn a first series of experiments, we created stimuli with 2 to 20short audio-visual (AV) events (moving white disk on a computerscreen, short tonal signal with Gaussian envelope), randomly dis-tributed over an interval of 2 s. The timing relation between audioand video for the individual events had a certain amount of ran-dom variation (jitter). Subjects had to discriminate AV sequenceswithout any temporal jitter from those containing a certain amountof jitter. Subjects turned out to be highly sensitive to detect smallamounts of jitter between the A and V (thresholds as low as 20ms), and thresholds were lowest if the sequences consisted of 5to 10 individual pulses. This sensitivity to jitter was not affectedby an additional constant overall delay between the whole audioand video sequence of up to +/- 100 ms. In a second series ofexperiments, we presented 2 to 6 random visual sequences inparallel, each made up of 20 short events occuring within a timespan of 6 s. Simultaneous with the video images, a sequenceof audio events was presented which had the same timing as


one of the visual sequences. The task of the subject was to se-lect, as quickly as possible, that visual sequence correspondingto the audio sequence. The necessary time for correct selec-tion increased roughly linearly with the number of simultaneousvisual sequences, being 1 s for two sequences and 2.6 s for sixsequences. This result is in line with a serial search model.


Cross-modal Effects of Visual Information on Auditory Pres-enceKenji Ozawa, Yoˆ Iti SuzukiInterdisciplinary Graduate School of Medicine and Engineering,University of YamanashiTwo experiments were conducted to investigate the effects of vi-sual information on auditory presence. (Presence is defined asthe subjective experience of being in a specific place or envi-ronment, even when one is physically situated in another.) Sev-enteen sounds, e.g. a sound of a train passing and a soundof the engine heard in a moving car, were binaurally recordedvia a dummy-head, and the corresponding moving pictures wererecorded using a digital video camera in live situations. Theexperiments were carried out using Scheffe’s method of pairedcomparison with eight subjects. In Experiment 1, only soundswere presented to the subjects via headphones. Two sounds,randomly selected from the seventeen sounds, were presentedsequentially. The subjects compared the two sounds in terms oftheir auditory presence, and gave rating judgment on a seven-point category scale. In Experiment 2, both sounds and movingpictures with 50-inch display were presented to the subjects. Theexperimental procedure was the same as that of Experiment1:The subjects were asked to evaluate the auditory presence ir-respective of the quality of the moving pictures. A scaling proce-dure was applied separately to the data obtained in the two exper-iments. Comparison between the results of the two experimentsrevealed that auditory presence showed a marked change if thecorresponding moving picture gave information on the originalsound field correctly such as when the sound source appearedin the picture. Moreover, the auditory presence was clearly en-hanced when visual objects in the picture moved.



Cross-modal Interaction Between Aural, Tactile, and Visualsenses: Sound Quality Evaluation Using the Virtual AircraftDaniel VästfjällDepartment of Applied Acoustics, Chalmers Univ of TechThe present researched examined cross-modal interaction in in-terior aircraft sound quality evaluation. Previous research hasmainly studied uni-modal (auditory or tactile) or bi-modal (audio-tactile) perception. The present study examines the perceptualeffects of sound, vibration, and visual input presented simulta-neously (multi-modal perception). A virtual aircraft for reproduc-tion of a visual environment, binaural sound, and lateral vibra-tions was constructed and used in an experiment. Sixteen par-ticipants judged their reactions to- and rated perceptual qualitiesof twelve different sound, vibration, and picture combinations in-cluded in the principal study design. The results showed strongcross-modal interactions. Inconsistent with some previous re-search, a subtractive interaction was obtained where annoyancedecreased with increase in modalities involved. The findings arediscussed in terms of a perceptual process explanation, the cog-nitive capacity hypothesis, that suggests that multiple stimulusinput may limit peoples’ cognitive resources, thereby resultingsubjective estimates different from those obtained when judgingstimuli in isolation.


Audio-Visual Experiments on a Life-Size VideoconferencingSystem Combining Spatialized Audio and 2D Video Projec-tionWerner De Bruijn, Marinus BoonePhilips Research EindhovenSpatialized reproduction of audio can in general greatly enhancethe feeling of ’presence’ for an audio-visual system such as alife-size videoconferencing system. A very realistic spatializedaudio reproduction, including a realistic reproduction of acous-tic source distance, can for instance be obtained with the tech-nique of Wave Field Synthesis. When such a sound reproductiontechnique is combined with conventional 2D video projection, thishas effects on the resulting audio-visual experience of observers,which are not very easy to predict because of the complicatedmechanisms of audio-visual interactions that are involved. Also,not all these effects are necessarily positive. Specifically, a mis-match between perceived auditory and visual source directionsmay occur for observers that are not in the ideal viewpoint of


the 2D video projection. This paper presents a series of subjec-tive experiments that have been carried out to investigate theseeffects in the context of a life-size video conferencing system. Is-sues that were investigated include the need for vertical sourceresolution, correspondence of auditory and visual source posi-tions, audio-visual source identification and overall impression of’realism’ of the audio-visual reproduction. Results show that thenon-identical perspectives of the audio and video reproductionsindeed have a significant influence on subjects’ evaluation of thetotal system and care has to be taken in the design of such audio-visual systems to avoid problems. A simple way to avoid severeproblems is presented as well.


Eliciting adaptation to non-individual HRTF spectral cueswith multi-modal trainingAlan Blum, Brian Katz, Olivier WarusfelOmniHeadThis paper presents the results of a series of tests which exam-ine the ability of subjects to adapt to non-individual Head RelatedTransfer Functions (HRTFs) in the context of auditory localiza-tion. Binaural presentations using the HRTF are currently lim-ited in quality due to individual differences in the HRTF whichare based on morphological variations between subjects. In con-trast to studies involving adaptation methods for generating indi-vidualized HRTFs, this study concerns the ability of subjects toadapt to non-individual HRTFs through a short interactive train-ing experience. Two groups were evaluated in the study, one us-ing non-individual HRTF spectral cues with individual Inter-auralTime Difference (ITD) and a second control group using individ-ual HRTFs. Subjects were blindfolded and the binaural render-ing was performed using IRCAM’s Spat software. Each subjectpassed two localizations tests separated by a 10 min trainingsession. The training session was presented in the context ofa search-game where subjects displaced a virtual sound source(linked to the position of the subject’s hand via a tracking sys-tem) to locate various virtual sound targets, all rendered binau-rally. Results show that localization performance improved for thegroup using non-individual HRTFs, leading to errors comparableto the control group, while little improvement was found for thecontrol group. This indicates that the improvement is not linked tothe training session in general, but to a perceptual adaptation tonon-individual HRTFs. Rapid adaptation to non-individual spec-tral cues has been shown to be possible using multi-modal inter-actions, in this case proprioceptive and auditory associations.


Th. 8:30 Schuman Ultrasonic transducers I

Broadband Amplitude and Phase Calibration of Hy-drophones and Impulse Deconvolution within Diagnostic Ul-trasound ExposimetryVolker Wilkens, Christian KochPhysikalisch Technische Bundesanstalt, FB 1.6 SchallReliable measurement of ultrasonic pressure fields requires hy-drophones calibrated in a broad frequency range. A secondaryhydrophone calibration technique using an optical multilayer hy-drophone as the reference is described. The optical hydrophoneoffers high lateral resolution and a constant frequency responsein a remarkably broad frequency range (1 - 75 MHz). By mea-surement of broadband ultrasound pulses with the optical hy-drophone, and in a second step with the hydrophone to becalibrated, the complex-valued frequency response is obtainedin a very fast, simple, and efficient way in a broad frequencyrange with high frequency resolution. The technique is appliedto calibrate both a piezoelectric membrane and a needle-type hy-drophone. The calibration data obtained can be applied to signifi-cantly improve hydrophone measurement results. This is demon-strated by exposure measurements on a typical diagnostic ultra-sound machine. The standard pulse parameters such as positivepeak pressure p+ and rarefactional peak pressure p- obtainedby the commonly applied evaluation method using the voltage topressure transfer factor at the acoustic working frequency M(fawf)are compared with those obtained by pulse deconvolution usingthe complete broadband complex-valued transfer function M(f).The membrane hydrophone is shown to systematically overesti-mate p+, underestimate p-, and overestimate the pulse intensityintegral PII if no broadband conversion is applied. Using a defi-cient needle-type hydrophone all pulse parameters were dramat-ically overestimated due to strong variations of the frequency re-sponse, but the results could be improved to a large extent usingthe broadband conversion method made possible by the pulsecalibration data.


Properties of acoustic waves guided by internal interfaces inpiezoelectric crystalsAlexander Darinskii, Manfred WeihnachtInstitute of Crystallography, Russian Academy of SciencesThe paper discusses the properties of the interface acousticwaves (IAW) guided by an interface inside piezoelectric media.The interfaces of two types have been considered. 1) Infinitesi-mally thin metallic layer inserted into homogeneous piezoelectriccrystal of arbitrary symmetry. 2) Rigidly bonded crystals whose


piezoelectric moduli differ by sign while the other material con-stants are identical; in this case, our analysis applies to the crys-tals of the lowest crystallographic symmetry allowing the fabri-cation of the structure desired, specifically, groups 2 and m. Anumber of general theorems has been proved regarding the exis-tence of IAW propagating slower than bulk waves. In particular, asufficient condition for the existence of such ”slow” IAW has beenderived. The propagation of leaky IAW has been studied. A spe-cial attention has been paid to the analysis of the situation whenthe imaginary component of the leaky IAW velocity vanishes, re-sulting in the appearance of non-attenuating IAW travelling fasterthan the slow transverse bulk wave. The branches of these ”fast”IAW have been found out in LiNbO3 and LiTaO3. A comprehen-sive study has been made of the bulk wave reflection from theabove interfaces. Analytical expressions for the coefficients ofmode conversion have been derived. An analysis has been car-ried out of specific singularities arising for the angles of incidencecorresponding to the resonance excitation of leaky IAW. The con-ditions for the occurrence of the resonance total reflection havebeen established. The computations performed for LiNbO3 andLiTaO3 illustrate general conclusions.


Acoustic wave measurements on SNGS crystals and deter-mination of material constantsEduard Chilla, Reinhard Kunze, Manfred Weihnacht, JoachimBohm, Robert Heimann, Margitta Hengst, Ulrich StraubeLeibniz Institute for Solid State and Materials Research DresdenSingle crystals of compounds with Ca3Ge(Ga2Ge)Ge2O14(CGG) structure, have been discussed as promising new mate-rials for SAW devices. Since they belong to the same trigonalsymmetry group 32 as quartz, similar acoustic properties can beexpected. Indeed it has been confirmed that the langasite-typecrystals LGS, LGN, and LGT may have potential SAW applica-tions. In particular, temperature compensated crystal cuts wereproved. Recently compounds of 4 component congruent meltingcompositions have caught big attention. Within this class of ma-terials Sr3NbGa3Si2O14 (SNGS) is of particular interest since ahigh electromechanical coupling factor is expected. Here we re-port on results of the material properties of SNGS. A starting setof elastic constants was derived from bulk wave measurements.Additionally, the angular dispersion of surface guided acousticmodes was measured. The surface acoustic waves were excitedby thermo-elastic laser absorption. The normal component of thesurface wave was detected by a piezoelectric PVDF foil trans-ducer. The angular dependence of the velocity was obtained by


mounting the sample on a computer controlled rotation stage.Additionally the temperature dependence was measured in therange between -10 ◦C and + 75◦C. Furthermore we report ondirect measurements of the SAW coupling coefficient.


Ultrasonic Transducers for Matching the Performance of Nat-ural Sonar SystemsAlexander Streicher, Rolf Müller, John Hallam, Herbert Pere-mans, Reinhard LerchDepartment of Sensor Technology, Friedrich Alexander Univer-sity Erlangen-NurembergInspired by bat’s well known proficiency in ultrasonic sensing,the CIRCE* (Chiroptera Inspired Robotic CEphaloid) project isbuilding a robotic reproduction of a complete biosonar system.Among others, two special challenges addressed by an interdis-ciplinary consortium are the development of pinna shapes opti-mized for biosonar functions and suitable ultrasonic transducers.The transducers have to match bandwidth, sensitivity (receiver),transmit efficiency (transmitter) as well as the overall insertionloss of living bats. The first step in the development of the pinnashapes was to obtain a 3D ear model from Micro-CT scans ofears from various bat species. The reflection and diffraction be-haviour of the model was then studied by means of finite ele-ment simulations. These results were verified by measurementson bronze ear models. In addition, an ultrasonic transmitter witha transducer area of 2.25 square centimetre was developed foremitting a chirp signals with a sound pressure level of more than90 dB in a distance of 1m. A new type of piezoelectric polymerfilm (EMFi foil) was used as transducer material. It has a reso-nance frequency of about 300 kHz, allowing a transmitter with abandwidth of 50 to 150 kHz. With the same material, an ultra-sonic receiver was designed and integrated into the pinna model.This sensor matches the bandwidth of the transmitter. We willdiscuss the simulation results for various designs of transmittersand receivers as well as corresponding measurement results.*(Supported by the European Commission, LPS Initiative)


Feasibility study for a primary free-field microphone calibra-tion technique in the low ultrasonic frequency rangeNourreddine Bouaoua, Thomas Fedtke, Volker MellertPhysikalisch Technische Bundesanstalt, FB 1.6 SchallToday ultrasound is extensively used in industrial and medical ap-plications. Evidence on the harmful health effects of exposure toultrasound suggests that caution should be taken in its use, but


until now no internationally agreed limits exist. In order to estab-lish appropriate limits and to test the output of ultrasound devicesthere is a need to develop reliable sound pressure measurementsin air in the frequency range from 20 kHz to about 150 kHz. Thispaper gives a preliminary study of a primary free-field calibrationtechnique for quarter-inch microphones by using the reciprocitymethod. This method is based on the measurement of the elec-trical transfer impedance of a pair of microphones coupled in thefree field, of the effective distance between the microphones, andof the air properties. The first step in this work was the measure-ment of the output signal of a Brüel & Kjaer microphone type 4135used as a sound source. In the measurement set-up two micro-phones 4135 were located face-to-face in an anechoic chamber.A comparison of the experimental difference between signals cor-responding to two different distances (10 cm and 20 cm) and thedifference predicted theoretically resulted in a good agreement.The measurements showed a good reproducibility and a suffi-cient signal to noise ratio. These results are encouraging to startthe development of a suitable reciprocity calibration method.


Experimental determination of the acoustical radiation resis-tance of a transducer: application to the noise factor mea-surements and transducer calibrationVincent Loyau, Guy Feuillard, Marc LethiecqGIP Ultrasons/ LUSSIFunctional characterisation of electro-acoustic transducer is gen-erally carried by the measurements of the pulse echo response,50 Ohm loop sensitivity, electrical input impedance and whennecessary radiation pattern. Little attention was paid to ex-perimental measurements of the acoustical radiation resistance.However this property appears very appropriate for the deter-mination of the noise factor or the efficiency of a piezo-electrictransducer. This concept is also suitable to easily make an abso-lute self-calibration of hydrophone or contact transducer in pulseecho mode. Thanks to energy consideration and to thermal noiseanalysis in piezoelectric transducer, theoretical formulas are cal-culated that show that the radiation resistance can be experimen-tally determined on the basis of pulse-echo and electrical inputimpedance measurements. Experimental measurements are re-ported in the case of immersion and contact transducer in themega Herzt range. They allow to deduce the noise factor, the ef-ficiency and the absolute sensitivity of transducers. These resultsof the experimental self calibration are compared to absolute dis-placements measured by a laser interferometer. Furthermore,several methods including direct current or impedance analyser


measurements are compared. The precision of each method isdiscussed. Finally, the approach based on the radiation resis-tance where few calculations are need, can be generalised to theother kind of acoustical transduction phenomenon such as ca-pacitive transduction, because only universal physical variablesare used in the calculations.


A Space Optimization Method for Time-Reversal Super-FocusingJens Rautenberg, Dirk Olszewski, Bernd HenningUniversity of Paderborn, Institute for Electrical Engineering andInformation Technology, Electrical Measurement TechniquesThe appliance of time-reversal acoustics to classical transducerdesign, medical, technical or audible range applications bringsforward new ideas whenever we need both, focusing acousticalenergy in time and space. Unfortunately, the spatiotemporal fo-cusing is limited through the amount of transducer elements aswell as the ergodicity and randomness of the cavity. This pa-per will present a novel but simple method to increase the nar-rowness of the refocused spot by breaking up randomness forthe benefit of ergodicity in a predetermined cavity. Based on thesimulated annealing technique, a multi-objective optimization al-gorithm, the positions of circular reflectors inside the cavity arerecombined in analogy to the molecules of a molten bath. Therearrangement follows a certain cost function according to theuniqueness of pulse responses from one transducer to differentfocal spots of interest and the temperature of the smelter. Themolecules or reflectors solidify with decreasing temperature sothat the result should be a well-regulated system in terms of thepreset objectives. Simulations and the appropriate experimentshave shown that there is an improvement in both temporal andspatial focusing. The temporal compression in the consideredexample is more than three times better in comparison to randommedia. This article will present the principle of the optimizationmethod as well as the results of asserted time-reversal experi-ments. With this the door is open for further developments in theabove-mentioned application areas.

Th. 13:50 Schuman Organ and room

The influence of different types of wind chests on the soundformation of flue organ pipesJudit Angster, Stephan Pitsch, András MiklósFraunhofer Institut BauphysikThe influence of different wind chests on the sound of flue organpipes has been investigated by voicing different Diapason pipes


on the slider chest and by measuring them on the slider chest andon a cone chest in the anechoic room of the Fraunhofer-Instituteof Building Physics. The attack transients of the pipes in bothcases have been analysed. The results show that the speechof the same pipe on different types of wind chests are different.It is assumed that at the very beginning of the attack differentpartials of the pipe sound have been excited on the different windchests by the edge tone. The most important characteristics ofthe attack transients are discussed.


The influence of new types of wind systems on the sound oforgan pipesStephan Pitsch, Martin Schaupp, Judit Angster, András MiklósFraunhofer Institut BauphysikBy building new organs large pressure oscillations may occur inthe wind system. These oscillations have to be reduced so thatthe played melody won’t be disturbed. On the other hand organ-ists express often the wish that the wind should be ’living’. Organbuilders are not able to set the wind pressure modulation (’thelivingness of the wind’) according to the wish of the customer.An innovative, computer controlled pressure regulation systemwith ”user defined” pressure response has been developed in theFraunhofer-Institute of Building Physics. With the help of a soft-ware the organist can choose the type of wind according to thestyle of music he is playing: living wind, normal wind and slowwind. The effect of different types of wind pressure oscillationson the pipe sound has been investigated. This research workwas supported by the European Union in the context of a CRAFTproject, in which 12 organ builder companies participated fromnine countries.


Expression Devices in Pipe OrgansJonas BraaschInstitut für Kommunikationsakustik (Web: www.rub.de/ika)In principle, three different swell systems are known in organs:the wind swell, the door swell, and the crescendo wheel. Withthe wind swell, the wind pressure supplying the pipes is changedusing a variable valve in order to enable the organ to be playeddynamically. Using the door swell, a similar effect is produced byenclosing a number of organ stops in a wooden cabinet, whichhas doors that can be shut to soften the sound of the pipes inside.The crescendo wheel is a device that allows the organ player toactivate or deactivate organ stops successively by a foot mecha-nism. In this investigation, several swell systems were measured


acoustically for their efficiency. The crescendo wheel was foundto be most effective and for frequencies around 2 kHz the in-crease in sound pressure level could be up to 50 dB betweenthe softest and the loudest adjustment. The maximum dynamicrange for the wind and the door swells was approximately 10 dBin the same frequency range. While the dynamic range is lowerfor the wind swell and the door swell, their advantage is the con-tinuous variability. For all three systems, the dynamic range wasdependent on frequency, in a similar way as it is found for orches-tral instruments. The effects of the wind and the door swells arequite similar, and the reason why wind swells went out of fash-ion is probably because they can be successfully applied only tofree-reed stops, while the door swell can be applied to all kindsof stops simultaneously.


Raumakustische Phänomene in Kirchen - Wechselwirkun-gen zwischen Orgel und RaumEva VeresLehrstuhl für Bauphysik der Universität Stuttgart und Fraunhofer-Institut für BauphysikIm Zusammenhang mit der Aufstellung und Intonation von Orgelnin Kirchen wird von Orgelbauern, Musikern und Zuhörern eineReihe von raumakustischen Phänomenen beobachtet, die nochnicht ausreichend bekannt und erklärbar sind. Ein Beispiel fürderartige Erscheinungen ist, dass einzelne Pfeifen eines Regis-ters nach der endgültigen Anordnung an ihrem Bestimmungsortlauter oder leiser erklingen, als es aufgrund der Vorintonationin der Werkstatt zu erwarten wäre. Im Rahmen des Vortrageswird die Frage gestellt, ob es möglich ist, solche Phänomene,die aufgrund der Geometrie und der akustischen Eigenschaftender Raumbegrenzungsflächen in jedem Raum unterschiedlich inErscheinung treten, durch messtechnische Untersuchungen vo-rauszusehen. Hierzu werden mithilfe der MaximalfolgentechnikRaumimpulsantworten in sechs Kirchen aus verschiedenen Stile-pochen gemessen und daraus die übertragungsfunktionen bes-timmt. Aus den Unregelmäßigkeiten im Frequenzgang der Rau-mantwort in der Nähe von musikalischen Frequenzen könnenHinweise auf die Rückwirkung des Raumes auf den Orgelklanggefunden werden.



Apparent Source Width and the Church OrganBrian Katz, Christophe D’AlessandroLIMSI-CNRSThe Concert Organ and the Cathedral are the two major ex-tremes of their disciplines: Musical Acoustics and ArchitecturalAcoustics. With that, they represent some of the most difficultproblems in both domains, violating many of the assumptions typ-ically used. The interest of the current work is an examination ofthe effectiveness and interpretation of the Apparent Source Width(ASW) in evaluating the acoustic of both the church and alsoof the instrument itself. The ASW is becoming more commonlyused in concert Hall acoustics as one of the descriptions of spa-ciousness of the hall. The measure of ASW is based on the Inter-Aural Cross-Correlation (IACC) from a binaural recording. Thepaper presents an investigation of the ASW in the context of thechurch acoustic. In addition, the church organ presents itself asa large distributed source, already having a non-negligible width.How the ASW varies with distance from the organ, in contrast to asimple source, is investigated as a potential means of measuringthe interaction between the organ and the church acoustic.


Mechanical Pipe Organ Actions and their Interface with thePlayerAlan WoolleyUniversity of EdinburghIt is widely, although not universally, believed that mechanicalpipe organ actions allow the player to exert some degree of con-trol over the speed of opening of the pallet and thus make subtlechanges to the initial speech of the pipe. This project investigateshow players might actually be able to control the pallet, particu-larly with reference to some of the characteristics of mechanicalactions such as pluck (the initial resistance felt at the key dueto the pressure difference across the closed pallet) and flexibilityin the action run (due to rollers twisting, cloth bushes compress-ing, levers bending etc). The work is being carried out usingan experimental organ that can be configured to replicate anydesign of mechanical action operating at any normal wind pres-sure, and also by attaching measuring devices to to real organsin order to measure how real players playing real music actuallydepress the keys in different circumstances. Initial studies showthat flexibility in the action causes the pallet to spring open whenthe key has been depressed sufficiently for the stored energy toovercome pluck, resulting in a degree of movement over which


the player apparently has little control. Pluck itself requires theplayer to reduce the force on the key very rapidly if the pallet isto be prevented from opening suddenly and out of control. Thelimits within which at least some players can exert some degreeof control have been investigated. The project also analyses thetactile feedback that a mechanical action provides and how theplayer might interpret and use it.


Attack transient analysis of flue organ pipes with modernmeasuring methodsTilo Wik, Judit Angster, András MiklósFraunhofer Institut BauphysikThe flue organ pipe is a complicated physical system whose func-tionality is not completely understood until now. The sound qual-ity of an organ pipe is mainly influenced by the attack transients.This onset is first dominated by the so called edge tone, whilelater the resonator of the pipe will play a more important role. Tounderstand the working of a flue organ pipe it is necessary toanalyze the transition phase of the edge tone and the stationarysound of the pipe. For the analysis a Short Time Fourier Transfor-mation is used. Since the resolution of this analysis method is notgood enough in the time and frequency domain to examine theshort attack transients of flue organ pipes, several improvementsof the STFT have been made. For the measurements severalspecial pipes have been used: narrow pipes whose onset is veryslow; a pipe of which the cut up is adjustable; a pipe of which thelength is adjustable. The results of the analysis of these organpipes will be shown and discussed.

Th. 8:30 Tivoli 1 Outdoor sound propagation II

Future Prediction Scheme for Sound Propagation from Ger-man RailwaysUlrich Kurze, Ulrich Moehler, Johannes OnnichMüller-BBM GmbHDevelopments in high speed rail traffic gave rise to start a revisionof the present German ,Schall 03”. Most important new aspectsresult from the consideration of different source heights for aero-dynamic sources, traction noise and equipment noise in additionto the rolling noise and to the consideration of octave band soundpower levels rather than A-weighted overall sound pressure lev-els at a reference distance. While the concept is widely con-sistent with the European regulation based on the Dutch model,the prediction scheme for sound propagation is even stronger re-lated to reliable engineering procedures by tailoring ISO 9613-2


to the needs of un-ambiguity and the availability of data describ-ing average meteorological and ground conditions. Sound prop-agation from segments of line sources at different heights willbe described in terms of geometrical divergence, standard con-ditions for atmospheric absorption, interaction with soft and rigidground, effect of barriers, a limited number of specular reflec-tions and a meteorological correction term. Other parameters,e.g. tree zones and general descriptions of built-up areas, willnot be taken into account.


Validation of Engineering Methods for Calculating Acousti-cal Diffraction by ScreensFabrice Junker, Fabien CrouzetEDF R&DEDF has been developing methodologies and tools for measuringand calculating the noise impact of its installations. The study ofthe noise impact of an industrial installation cannot be achievedby using complex propagation models. The use of engineeringsimplified models is unavoidable. According to the recent hard-ening of European noise policy, the simplified calculation modelshave to be more and more accurate. New simplified models aregoing to be proposed by European work groups. In this context,EDF wants to take an active part into the validation of these kindsof models. Industrial noise often deals with real 3D diffractionproblems on quite hard ground with tonal sources which leadsto strong interference patterns. Usual simplified methods (ISO,NMPB, oe) are often based on the calculation of the differencebetween the direct and the diffracted path lengths. The followingpaper presents the results of a comparison between such a sim-plified model and a 3D code based on Linearized Euler Equationsused for calculating acoustical diffraction by a cubic screen.


Meteorological effects on long-range sound propagation:evaluation of the long term sound level using statistical anal-ysis.David Ecotiere, Benoît Gauvreau, Yves BrunetLaboratoire Régional des Ponts et ChausséesThe temperature and wind gradients influence on long-rangesound propagation is a well known subject. But at present, itis very difficult to estimate a reliable long term sound level fromone measured on a short period. This paper presents some sta-tistical distribution properties of theoretical sound levels createdby a point source over 29 years. The method is based on the


coupling of a meteorological model with a model of sound propa-gation. A serie of standard micrometeorological data, either pro-vided by local meteorological offices or measured on a long termmonitoring experimental site (St Berthevin, France), is used tosimulate hourly profiles of sound celerity vertical gradients over avery long period, and their set of hourly sound attenuations. Thestatistical distribution of equivalent sound levels is studied for dif-ferent periods of reference over a long period (29 years): oneday, one night, one hour. The analysis provides typical cumula-tive statistical distribution of sound levels which can be used toappreciate the ’long term quality’ of experimental data (for mea-surement conditions close to the theoretical ones). A regressionstatistical model, based on a polynomial decomposition of thesound energy, is also obtained and supplies some help on esti-mating a long term equivalent sound level from the value of oneof the reference period.


Including anisotropic turbulence into outdoor sound propa-gationBernhard Schwarz-RöhrCarl von Ossietzky Universität OldenburgCommon methods to describe sound propagation in turbulentmedia like the parabolic equation method (PEM) rely on the as-sumption of locally isotropic turbulence. Experiments show thatthis condition is not met in the atmospheric boundary layer. It isdiscussed, how the correlation tensor of the velocity fluctuationsis obtained from anemometer data. By reviewing different deriva-tions of the PEM methods to incorporate non-isotropic turbulenceinto the theory are discussed.


Consideration of the Local Climate in the Prediction of long-term sound levelsDietrich Heimann, Reinhard BlumrichInstitut für Physik der Atmosphäre, Deutsches Zentrum für Luft-und RaumfahrtThe propagation of sound over distances of more than 200 mis largely influenced by meteorological factors. In long-termnoise prediction (e.g. of Lden) the local climate provides therelative contributions of different meteorological situations beingfavourable or adverse with respect to the propagation of noise.The paper presents a quantitative estimation of the climate ef-fects on long-term noise predictions, proposes meteorologicalclassifications, and sketches solutions for implementing them inpracticable prediction tools for surface and air traffic noise.



Street Canyons and Quiet Side: Comparing FDTD Simulationand Engineering ModelsTom De Muer, Timothy Van Renterghem, Bram De Greve, DickBotteldoorenAcoustics Group, Department of Information Technology, GhentUniversityRecently, the impact of having access to a quiet side of thebuilding on the perceived quality of the living environment hasbeen pointed out. Ongoing studies aim at quantifying the ef-fect of such a quiet area. In the urban environment continuousrows of houses screen sound propagation efficiently thus cre-ating these quiet places. At the same time sound sources getenclosed in so called street canyons having their own particularacoustic features. Finite difference time domain (FDTD) numeri-cal models for sound propagation in background flow, sometimesalso referred to as Linearized Euler models (LEE) are perfectlysuited to account for the important determinants of the quiet-sidesound field (diffraction, wind induced refraction, turbulent scatter-ing, and diffuse reflection on façade roughness). However, theirdemand on computer power limits their use to rather simple ge-ometry and makes them unsuitable for modeling cities or parts ofcities. Engineering models such as ISO 9613 or the more recentNord 2000 are far more appropriate for this purpose. The pa-per presents a number of street-canyon-and-backyard test casesfor which engineering models are evaluated by comparing the at-tenuation they predict to the more detailed FDTD model. Guide-lines for selecting parameters of the existing engineering modelssuch as the required number of reflections taken into considera-tion are extracted. Suggestions for improving future engineeringapproaches are made.


Long term monitoring site at Saint-Berthevin (France-53): a tool for traffic noise characterisation using space andtime statistical variability of acoustical and meteorologicalevents.Olivier Baume, Benoît Gauvreau, Michel Bérengier, FabriceJunker, Francis LauzinLCPCThe large influence of atmospheric conditions and ground irreg-ularities on noise level calculation is well known from theoreticalapproaches or numerical developments. For instance, comput-ing the propagation of traffic noise has held great efforts sincethen but those works were based on approximate environmental


conditions. This paper deals with further investigations for real-istic situations using statistical analysis. We aim at introducingour long term monitoring site that was settled for new researchdevelopments. The double objective of this important equipmentis to validate of our numerical models for acoustical (PE basedmodel) and meteorological (SUBMESO) predictions, and to leadto a statistical approach. Thanks to facilities supported by thePonts et Chaussées laboratories network and specifications ofSaint-Berthevin valley - complex topography, sound source fromroad and railway traffic - a great tool for such analyses is avail-able. A software which verifies output data from this long termmonitoring site (10s sampling) is currently in progress. It leads toa wide validated database of road traffic, acoustical and meteo-rological measurements controlled from corrupting events in non-urban areas. Then we explore new statistical theories and toolsfor both space and time correlation of those experimental figures,including multi-dimensional analysis. The purpose is to estimatethe variability of noise levels for several time scales, from shortterm (10s duration) to long term (10 years) analysis to appreciatethe ”long term quality” of experimental data.

Th. 13:50 Tivoli 1 Ultrasonic transducers II

Flowmeter and audio application of wideband ultrasonictransducersJürgen Peissig, Vladimir Gorelik, Rainer WiggersSennheiser Electronic GmbH&Co.KGThe ultrasonic (US) transducer based on Sell’s principle is wellknown to work invertible as microphone and speaker with abroad-band frequency response. US transducers are used formovement and distance sensors, flow-meters and in parametrictransducers where it is important to have a high US sound level inair and also good directivity. Different versions of Sell transducerswith different power and directivity properties have been devel-oped and examples of applications are shown. We discuss top-ics concerning long term stability, electrical and acoustical prop-erties, design of the transducers as well as the electrical drivingunits for microphone and speaker operation.


Th. 14:10 Tivoli 1 Ultrasonic transducers IIReal time beam steering using an ultrasonic one channeltime-reversal mirror coupled to a solid cavityNicolas Quieffin, Stefan Catheline, Ros Kiri Ing, Mathias FinkESPCI - LOABeam steering and beam forming is achieved using a time-reversal process and a unique transducer coupled to a solid cav-ity. This low cost technique allows one to focus acoustic en-ergy anywhere on a 3-D domain with a spatio-temporal resolutioncomparable to multiple transducers array. We first record the sig-nal emitted by the transducer and detected by a hydrophone nee-dle at a reference point. The signal received is then time-reversedand remitted using the same transducer. At the reference pointone can observes a spatio-temporal recompression. More over,it is shown how the experimental Green’s functions at the surfaceof the cavity can be used to control the emitting ultrasonic field.A careful study of this phenomena leads us to better understandthe resolution of the focusing system: the side-lobe level as wellas the focal width are no more dependent on the transducer aper-ture but on the dimensions of the solid cavity. The signal-to-noiseratio of such a system is explained by a modal theoy and leads todefine four influencing parameters: the frequency bandwidth, thenumber of transducers, the geometry of the cavity and the timereversed signal duration. Frequency analyse allows to define aone channel Inverse filter: its efficiency is compared to the timereversal one and linked to the modal theory.

Th. 14:30 Tivoli 1 Ultrasonic transducers IIStudy of the performances of an ultrasonic acoustic genera-tor producing an audible directive beamAlexandre Ritty, Etienne Auger, Pascal Hamery, Pierre NazI.S.L. : Institut franco-allemand de Recherche de Saint LouisIt’s possible to generate an audio frequency signal, within a nar-row beam, with an ultrasonic parametric antenna. This ultrasonicgenerator has many applications i.e., in a large meeting to com-municate with given people without interfering with others. Forthese applications, it’s necessary to assess the performance ofthe systems, as a function of the distance to the source. First,the theoretical principles of these directive ultrasonic generatorsare summarized. Next, experimental measurements, in anechoicchamber and in free field have been performed with two differentdevices. These measurements enabled to underline the differ-ences between the two different antenna technologies : ceram-ics’ array and PVDF film. The free field measurements allowedto compare conditions of the propagation of the acoustic signalswith the theory.


Th. 14:50 Tivoli 1 Ultrasonic transducers II

Measuring Spatial Cross Sections of Ultrasonic PressureFields by Fast Optical MeansMartin Klann, Christian KochPhysikalisch Technische Bundesanstalt, FB 1.6 SchallThe measurement of spatial cross sections of ultrasonic pres-sure distributions is an essential element of exposimetry of ul-trasonic medical equipment. An optical technique is presentedthat allows the two-dimensional determination of ultrasonic pres-sure. A dielectric optical multilayer coating on a 25 mm diame-ter glass substrate forming a micro Fabry-Perot interferometer isused as ultrasound probe. The beam of a stabilized laser diodewith suitable wavelength is focussed on the probe. By detectingthe change in reflectivity of the coating induced by the incidentultrasound, the pressure waveform can be determined. For two-dimensional acquisition, the laser beam is scanned across thearea of interest by a micro mechanical engineered scanning mir-ror that is capable of independently deflecting the laser beam intwo perpendicular axes. This serial detection scheme allows themeasurement of repeating ultrasonic waveforms such as pulsesat several hundred spatial points on the probe with a good sig-nal to noise ratio. In an alternative approach incorporating theparallel processing capabilities of a CCD chip, the probe is illu-minated by a large-diameter collimated beam of a pulsed laserdiode that emits pulses with a width of about 15 ns, much shorterthan the ultrasound period. The pressure distribution at a par-ticular moment is derived from the captured reflectivity distribu-tion. By delaying the laser pulse with respect to the ultrasonicpulse, the complete pulse waveform can be acquired with highspatial resolution. Measurement results on ultrasound fields fromplain and focussing transducers obtained by these two differentapproaches are presented and individual advantages and draw-backs are discussed.

Th. 8:30 Tivoli 2 Medical acoustics II

A Tube Headphone Without Metallic Parts To Be Used ForFunctional NMRGottfried Behler, Tobias LentzInstitute of Technical AcousticsFor the investigation of neuronal activities modern magnet res-onance tomography provides the best possibilities for both localand time dependant resolution. Investigation of particular inter-esting parts of the brain (e.g. auditive cortex) are performed byapplying appropriate stimuli and scanning the time dependant ac-tivity using specially designed magnetic sequences in the tomo-graphs transducer. A major problem with NMR is the noise that is


produced by these sequences, which on one hand interferes withthe stimuli applied and on the other hand requires precautionsfor the protection of the subjects ears. Usually this is solved byusing capsule ear protectors which in many cases are addition-ally equipped with tube phones for communication purpose. Thepoor quality and the weak audio level provided, however, makesthe usage of these devices impossible for the presentation of thestimuli. To overcome with these shortcomings a hearing protec-tive headphone with a wide frequency range and high level ca-pability is required that has to be free from magnetic and currentleading parts. Therefore a tube phone system was designed, thatuses a common capsule ear protector and a flexible tube of 4 mlength, thus providing the possibility to place the electro-dynamictransducer as far away as possible from the tomograph. Due toextremely high damping of the high frequencies in particular aspecial treatment was needed. The system was realized usingwide band compression drivers and digital FIR filtering to main-tain the aimed dynamic and frequency range.

Th. 8:50 Tivoli 2 Medical acoustics II

Searching for phonological processing in the human brainusing functional MR imagingStefan Uppenkamp, R. Patterson, I. Johnsrude, D. NorrisMedizinische PhysikFunctional magnetic resonance imaging (fMRI) allows the visu-alization of neuronal processes in the brain with a spatial reso-lution of several millimetres and a temporal resolution of a fewseconds. The combination of anatomical and functional imagesfrom the same listeners is a unique tool to directly relate physi-ological processes to anatomical structures in the brain regionsof interest. The main problem with fMRI in the auditory modalityis the distinction between controlled acoustical stimuli and un-wanted noise, that is produced by the MRI scanner during dataacquisition. One way to solve this problem is ,sparse temporalsampling”, that is, acoustical stimuli and scanner noise are sepa-rated in time, as suggested by Hall et al. (Human Brain Mapping,vol. 7, pp. 213-223, 1999). During this study, functional MRIin a sparse imaging paradigm was used to search for phonolog-ical processing in the human brain. Using a set of synthetic En-glish vowels and a set of spectrally matched contrast stimuli thatsound nothing like speech (Uppenkamp et al., DAGA 2001, pp.106-107), we identified a region in the auditory system, wherespeech sounds are first distinguished from nonlinguistic sounds.When contrasted with silence, all of the sound conditions showremarkably similar activation patterns, centred around Heschl’s


gyrus bilaterally, with the most prominent peak towards the lat-eral end of HG. The first processing stage that distinguished thespeech sounds from the non-speech sounds was in the superiortemporal sulcus (STS) lateral and inferior to auditory cortex.

Th. 9:30 Tivoli 2 Speech and voice - analysis and synthesis

Buzzing lips and vocal folds: the effect of acoustical feed-backA. Van Hirtum, Ines Lopez, M.H. Schellekens, X. Pelorson, N.Driessen, A. HirschbergInstitut de la Communication Parlée - INPGBuzzing of lips or vocal folds is controlled by lip tension, initialopening, lung static pressure and acoustical response of the vo-cal tract. The static response of the lips to the lung pressureprovides an indication for the lip stiffness. The dynamic responseto acoustic forcing (with and without flow) provides informationabout the resonance modes of the lips: frequencies and qualityfactor. The order of magnitude of the effective mass in a lumpedparameter model can furthermore be estimated from fluid dynam-ics considerations. Experiments show that the critical blowingpressure for the onset of buzzing is strongly dependent on theacoustical loading of the system. This critical blowing pressureshows a minimum when the lip tension is adjusted to close theglottis at zero lung pressure. The results of these experimentsindicate that our lips do not perform as expected for vocal folds,which are much less sensitive to acoustical loading. The me-chanical boundary conditions of the lips may play a crucial rolein explaining this difference. The experimental results are com-pared with a single mass model analogous to the model of Cullenen the two-mass model of Lous et al. (1998). A linear stabilityanalysis is used to predict the onset of oscillation, while a non-linear model provides a prediction of the established buzzing be-haviour.


On the acoustic sensitivity of a symmetrical two-mass modelof the vocal folds to the variation of control parametersDenisse Sciamarella, Christophe D’AlessandroLIMSI-CNRSThe acoustic properties of a recently proposed two-mass modelfor vocal-fold oscillations are analysed in terms of a set of acous-tic parameters borrowed from phenomenological glottal-flow sig-nal models. The analysed model assumes a symmetrical glot-tal structure and includes a novel description of flow separationwithin the glottal channel at a point whose position may vary in


time when the channel adopts a divergent configuration. Mea-suring the sensitivity of acoustic parameters to the variation ofthe model control parameters is essential to describe the actionsthat the modelled glottis employs to produce voiced sounds ofdifferent characteristics. In order to classify these actions, weapplied an algorithmic procedure in which the implementation ofthe vocal-fold model is followed by a numerical measurement ofthe acoustic parameters describing the generated glottal-flow sig-nal. We use this algorithm to generate a large database with thevariation of acoustic parameters in terms of the model control pa-rameters. We present results concerning fundamental frequency,intensity and pulse shape control in terms of subglottal pressure,muscular tension, and the effective mass of the folds participat-ing in vocal-fold vibration. Finally, we produce evidence for theidentification of vocal-fold oscillation regimes with the first andsecond laryngeal mechanisms, and simulate electroglottographicsignals with the vocal-fold model. A strong correspondence isfound between the features of experimental and numerical elec-troglottograms during the transition between different laryngealmechanisms.


A virtual real-time room simulation to determine the influ-ence of the room acoustics on voice qualityPhilipp Heck, Malte Kob, Tobias Lentz, Christiane Neuschaefer-RubeDep. of Phoniatrics, Pedaudiology, and Communication Disor-ders, University HospitalProfessional speakers often suffer from voice diseases that arepartially caused by uncomfortable conditions in the performanceroom. Among these conditions, reverberation time and back-ground noise are of importance. Whereas the interaction be-tween room and voice has been extensively studied with focusupon perceptual questions such as room-listener interactions, thevoice performance of professional speakers influenced by roomconditions have not yet been well investigated. One reason mightbe that for the assessment of voice quality in the actual environ-ment of a speaker, both subjective and objective methods wouldsuffer from the ambient noise as well as from the alteration of thevoice signal due to reflections within the room. For evaluation ofthe room acoustic influence on the voice quality a virtual acous-tic environment has been realised. This set-up makes use of alow latency convolution algorithm which allows to simulate arbi-trary rooms. By using a speaking and listening artificial head thebinaural room impulse response can be measured, including thehead related transfer function from the mouth. The total latency


achieved with the set-up has been proven to be sufficiently shortfor realistic simulations of voice performances in normal rooms.The correlation between voice quality of several speakers and theroom acoustics of different rooms is described by the assessmentof the change in voice quality perceived by a phoniatrician andanalysis of objective voice parameters in different rooms. Firstresults are presented.


Cued Speech production: giving a hand to speech acousticsVirginie Attina, Denis Beautemps, Marie-Agnès CathiardInstitut de la Communication Parlée - INPGHearing losses often lead deaf people to use visual cues for per-ceiving speech through lip-reading. However multiple misunder-standings occur due to the intrinsic similarity of the visual lipshapes corresponding to different speech units. Manual CuedSpeech (CS) is an easy accessible method that allows peoplewith hearing impairments to receive a complete message throughthe visual channel. Usually used by hearing people to deaf peo-ple, CS is a syllabic code involving the use of the hand in ad-dition to lip gestures. The speaker enhances each syllable hepronounces with a manual cue. The present study aims at inves-tigating how a proficient user of French CS coordinated his handwith the lips and the sound emitted. The analysis is based onthe labelling and the comparison of the following different signalsin time: hand trajectory, finger gestures, lip area time-course inrelation with corresponding acoustic signal. Results showed anadvance of the hand on the lips and on the sound relatively to thesyllable.


Application of impedance measurements for articulatorydysfunctionMalte Kob, Julia Stoffers, Matthias Lievens, Roman Katzer, Chris-tiane Neuschaefer-RubeDep. of Phoniatrics, Pedaudiology, and Communication Disor-ders, University HospitalThe application of acoustic impedance measurements for thenon-invasive characterisation of the resonance structure in thevocal tract has been reported earlier (M. Kob: Miniaturaufbauzur direkten Impedanzbestimmung, DAGA ’02). The first methodsuffered from the problem that the impedance measurement isdistorted by the voice signal during measurements with phona-tion. On the other hand, during the measurement of the vocaltract resonances without phonation, the configuration of the vo-cal tract and the glottal area is not exactly known. Therefore, a


comparison of the impedance measurements with results fromestablished methods, as e.g. LPC analysis, was difficult. Analgorithm was developed that eliminates the voice signal fromthe measured acoustic impedance at the mouth. The impedancemeasurements were validated by simultaneous measurements offormants (LPC) and vocal tract transfer functions (VTTF) of an ex-ternally excited vocal tract model. The results give valuable hintsfor the interpretation of vocal tract impedance measurements inpatients with articulatory dysfunctions.


Measuring Pitch with Historic Phonetic DevicesRüdiger Hoffmann, Dieter MehnertInstitut für Akustik und SprachkommunikationRecording the pitch and the intonation contour of words and sen-tences has been focused by phonetic and linguistic researchsince a long time. There was recognized very soon that a suf-ficient description is not possible by means of human hearingalone. Instead, experiments and measuring devices were de-veloped for pitch analysis. However, the investigations offereda lot of problems and were very time-consuming. The DresdenUniversity of Technology owns a collection of historic phoneticequipment at the Institute of Acoustics and Speech Communica-tion. This collection is recently prepared for a web presentation.Apart from this activity, selected devices are reconstructed andprepared for demonstrations in suited lectures (e. g., in psychoa-coustics, signal processing, or speech technology). Until now,we demonstrated the chain of sound emission (by a larynx modelof Wethlo combined with a vocal tract model), sound recording(by a kymograph), and sound analysis (by a mechanical Fourieranalyzer). A text has been developed as supporting material forthe students also. This paper describes methods and equipmentfor the measurement of pitch from the early days of experimentalphonetics. We furthermore discuss the measuring accuracy andthe subsequent development. This description is illustrated usingdevices from the historical collection of our institute.


Wizard of Oz tests for a dialog system in smart homesJan Krebber, Sebastian Moeller, Rosa Pegam, Ute Jekosch, Mar-tin Rajman, Miroslav MelicharInstitut für Kommunikationsakustik (Web: www.rub.de/ika)Within the scope of the European IST-project INSPIRE (INfotain-ment management with SPeech Interaction via REmote micro-phones and telephone interfaces) a speech-dialog system foraccessing different kinds of home appliances (TV, VCR, lamps,


blinds etc.) is currently developed. The purpose of the system isto provide an intelligent and uniform user interface. The interfaceis capable of supporting the user by controlling different complexdevices and increasing the acceptance and quality of the ser-vices. The system is controlled via microphone arrays for homeuse or by telephone or internet access for remote use. The Wiz-ard of Oz (WoZ) replaces the automatic speech recognition andallows to set different error rates. More over it allows to test dif-ferent metaphors. The presentation will focus on the architectureof the WoZ tool and the way how it was used to test the quality ofthe dialog system and the overall quality.


Grapheme-to-Phoneme Conversion in Mandarin ChineseText-to-SpeechHongwei Ding, Oliver JokischInstitut für Akustik und SprachkommunikationWe present a lexicon-based model for segmenting Chinesetext into dictionary entries and provide pronunciations for thesewords. This approach adopts a matching algorithm combinedwith several heuristic rules to resolve the ambiguities. It canachieve an accuracy over 98%, which proves to be an effectivesolution to grapheme-to-phoneme conversion for Mandarin Chi-nese. The written Chinese texts are composed with strings ofcharacters without blanks to delimit words. The first step in textanalysis is to segment a sequence of characters into words. Thelexical-based word segmentation approach is to match the in-put character strings with entries in a large lexicon. The mosteffective matching method [1] says that the most plausible seg-mentation is the three-word chunks with maximal length. This al-gorithm is adopted in our system, some modifications are madeto deal with numerals and personal names. A few morphologi-cal rules are then applied to allow for morphologically complexwords that are not in the dictionary. The same lexicon will alsoprovide the words with right pronunciations after the words arecorrectly segmented. This method is reported as one of the mosteffective ones in word segmentation. In order to achieve a betterperformance, statistical methods can also be combined. Liter-ature [1] Chen, K. and Liu, S., Word Identification for MandarinChinese Sentences., In Proceeding of COLING, pages 23-28,August 1992


Th. 8:30 Gutenberg Wave field synthesis II

Spatial perception in WFS rendered sound fields: Distanceof real and virtual nearby sourcesHelmut WittekInstitut für RundfunktechnikIn theory Wave Field Synthesis is capable of reproducing a soundfield by means of loudspeaker arrays. It is the goal to make acopy of the original sound field i.e. to render a virtual sound fieldwith equal temporal and spatial characteristics. However, it hasbeen shown that the characteristics are similar but not congru-ent, due to principal as well as practical reasons. For example,the head shadowing effect in the WFS rendered sound field dif-fers, resulting in impairments of the monaural and interaural cues.This leads to the question of where compliances and differencesare with regard to auditory perception. Considerations are madeto illuminate the case of distance perception of virtual sources,and, in particular, the role of the curvature of the wave front fordistance perception. A companion paper describes correspond-ing experiments undertaken.


Experimental investigations into the distance perception ofnearby sound sources: Real vs. WFS virtual nearby sourcesStefan Kerber, Helmut Wittek, Hugo Fastl, Günther TheileAG Technische Akustik, MMK, TU MünchenWave field synthesis (WFS) is a technique which in principle isable to reproduce the temporal and spatial properties of a wave-field. Therefore, it should be possible to create exact interau-ral differences at a listener’s head. They represent cues to nearfield distance perception, and should therefore lead to naturaldistance perception. This paper examines this assumption as fol-lows: listening tests are performed in a non-reflecting room withvirtual sound sources created by WFS, as well as with real loud-speakers at various distances (25cm to 190cm) from a person.The results confirm the suggestion described in the precedingcompanion paper that the direct sound rendered with a typicalWFS setup does not create sufficient binaural cues for distanceperception.



Spatial perception of virtual 3D sound scene: how to assessthe quality of 3D audio rendering by WFS?Rozenn Nicol, Laetitia GrosFrance Télécom R&DIn the context of the CARROUSO Project, listening tests are car-ried on, in order to assess the quality of the 3D-audio render-ing provided by WFS. The experiment is focussed on WFS ren-dering, which will be compared with other sound spatializationrendering systems, such as Ambisonics, intensity panning, and5.1. All these systems are based on 3D-audio rendering providedby loudspeaker array of more or less complexity and the variousexperiments use a common 3D audio demonstrator, which con-sists in a circular array of 48 loudspeakers. In order to assessthe quality of the 3D-audio rendering, two different, but comple-mentary aspects are considered: first, the localization accuracyprovided by the system, second, the overall quality, through dif-ferent criteria, such as intelligibility, realism or immersion. Thelocalization test focuses on the comparison between WFS andAmbisonic. On the other hand, for the quality test, WFS is com-pared to several sound spatialization systems, through three ex-periments: first, a speech intelligibility test, second, a test basedon the collection of multi criteria judgment, in terms of natural-ness, space impression, envelopment, accuracy and agreement.The third experiment focuses on immersion and consists in eval-uating how a subject feels involved into a virtual complex soundscene. By this way, it is also intended to derive innovative andcomprehensive test methodologies in order to assess the per-ceptual aspects of 3D audio system rendering. The paper willdetail and discuss the results of the various experiments.


Perceptual Spatial Exploration of WFS SoundscapesOlivier Warusfel, Etienne Corteel, Terence CaulkinsIRCAMWave field synthesis (WFS) provides an accurate reproductionof a sound field over an extended listening area. Depending onthe position of the virtual source, the wave front exhibits a givencurvature and the listener can experience the continuous updateof auditory localisation cues while wandering around the sound-field. Another possibility of WFS is to take into account the radi-ation properties of the simulated sound source in order to shapethe sound field and its interactions with the reproduction room.These properties allow new listening conditions where the lis-tener may navigate in the sound scene with consistent acoustical


cues variations. This calls for new methods for spatial percep-tion investigation where auditory perception must be integratedinto a multisensorial frame. Especially, the congruence of audi-tory cues variations with idiothetic cues elicits the perception ofthe auditory spatial perspective. The study is illustrated with testsdedicated to the monitoring and perceptual assessment of soundscenes created in a WFS installation. In a first experiment, westudy the necessity for maintaining independently the monitoringof the distance of sound objects through the conventional directto reverberant ratio and through the WFS specific wave curvaturecontrol. In a second part, we study the influence of the interac-tion between the sound field generated by the WFS system andthe reproduction room. This interaction is analysed with regard tothe consistency between the resulting room effect and the actualacoustical properties of the reproduction room.


Creating plausible auditory virtual environments for WaveField SynthesisRenato PellegrinisonicEmotion AGWave field synthesis is a strong technology that allows to recre-ate the wave fronts of any number of virtual sound sources ina given environment. In this paper we discuss the achieveablelocalization accuracy, and the usage of discrete reflections to im-prove distance & room-size perception for a given auditory scene.A rendering scheme is introduced with distributed localized ren-dering in a low-latency network.


Perceptive evaluation of road traffic noise inside buildingsusing a combined image and wave field synthesis systemJulien Maillard, Jacques Martin, Jacques LambertCSTBThe evaluation of transport infrastructures in terms of environ-mental pollution remains a difficult subject due to the complexityof the disturbance under study. To be effective, the evaluationshould be done in an environment where the main parameters ofthe disturbance can be controlled precisely. On-site experimentsare therefore not suitable. This motivates the use of Virtual Real-ity which gives complete control over the parameters of the sceneunder study. This paper presents a practical application of vir-tual reality techniques to provide a multi-criteria evaluation tool ofroad traffic noise as it is experienced inside buildings. The ap-proach described here creates an auditory and visual display ofroad infrastructures as perceived from inside a room. The main


objective is to provide a near-to-real environment. The subjectsare free to move within a real room featuring a window, the otherside of which is equipped with the virtual display system. The ap-proach combines high resolution video restitution and an audiosystem based on Wave-Field Synthesis. A description of the sys-tem is given, focusing on the sound field synthesis and restitutionof the road traffic noise.

Th. 13:50 Gutenberg Assessment of noise . . .

The European Directive relating to assessment and manage-ment of environmental noise and the harmonisation of noiseassessment methodsVolker IrmerUmweltbundesamt BerlinThe European Directive 2002/49/EC relating to the assessmentand management of environmental noise obliges the MemberStates to draw up strategic noise maps for major roads, railways,airports and agglomerations, using harmonised noise indicatorsLden (day-evening-night equivalent level) and Lnight (night equiv-alent level). One of the goals of the Direcitve is to get compara-ble data on the noise exposure in the different Member States.Therefore the methods to assess the noise exposure should beharmonised. Such harmonised methods do not exist now, the Di-rective leaves it to the Member States either to use their existingnational methods, that have to be aligned with the provisions ofthe Directive, or to use interim methods laid down in the Directive;these methods are not in line with the provisions of the Directiveand changes have to be made to fulfil these provisios. Thereforethe European Commission has adopted a Recommendation con-cerning the guidelines on revised interim computation methods.The objective, however, is to get and publish harmonised assess-ment methods, which should then be used all over Europe. Tothis end a European project ”HARMONOISE” is currently carriedout. Detailled information is given on this process.


Die Interimsverfahren zur Berechnung der Lärmbelastung inder UmgebungslärmrichtlinieEdgar WetzelWölfel Meßsysteme · Software GmbH & CoIm Rahmen der Umsetzung der Richtlinie 2002/49/EG hatdie General-Direktion Umwelt der Europäischen KommissionLeitlinien zu den angepassten vorläufigen Rechenmethodenam 22.08.2003 als ,EMPFEHLUNG DER KOMMISSION vom6. August 2003 über Leitlinien für die geänderten vorläufigenBerechnungsmethoden für Industrie-, Flug-, Straßenverkehrs-


und Eisenbahnlärm und diesbezügliche Emissionsdaten” imAmtsblatt der Europäischen Union veröffentlicht. Sie kommtdamit einer Verpflichtung aus Artikel 2.2 des Anhangs II derRichtlinie 2002/49/EG nach. Die Leitlinien der Kommissionbasieren auf den Ergebnissen der Studie ,Adaptation and re-vision of interim computation methods for strategic noise map-ping”. Die vorläufigen Rechenmethoden werden zur rechner-ischen Bestimmung der Lärmindikatoren Lden und Lnight instrategischen Lärmkarten jenen Mitgliedstaaten empfohlen, dienicht über eigene nationale Rechenmethoden verfügen. Die inder Richtlinie genannten Rechenmethoden sind ,vorläufig”, weilsie nur bis zur Einführung einer europäischen, harmonisiertenRechenmethode zum Einsatz kommen sollen. Bis dahin sindjene Mitgliedstaaten, die über eigene nationale Rechenmeth-oden verfügen ermächtigt diese anzuwenden sofern eine An-passung an die Forderungen der Richtlinie 2002/49/EG erfolgt,und der Nachweis der Gleichwertigkeit der Ergebnisse erbrachtwird. Unter dem Aspekt der Verwendung bis zur Einführungder harmonisierten Rechenmethode sind auch die nationalenRechenmethoden als ,vorläufige” Rechenmethoden für die Er-stellung strategischer Lärmkarten zu sehen, ungeachtet ihrerunangetasteten Gültigkeit in nationalen Verfahren. Es wird derFrage nachgegangen, welche Anforderungen an nationale Meth-oden sich ergeben aus den Empfehlungen der Kommission undmöglicherweise aus anderen im Rahmen der praktischen Um-setzung der Richtlinie 2002/49/EG durchgeführten europäischenoder nationalen Studien.


Geometric Post-Processing of GIS Data for Noise MappingHardy Stapelfeldt, Douglas ManvellBrüel & Kjaer Sound and Vibration Measurement A/SGIS data can help generate acoustic models. But this datahas typically been collected without any consideration of thedemands placed by acoustic calculations. Therefore, in manycases, efficient post-processing of geometry and attribute infor-mation turn out to be essential. Various aspects of this processwill be addressed using actual case studies: * Bringing data intothe proper shape (generating building polygons from single ver-tices, etc.) * Terrain models: Contour lines vs. ridge models,reconstructing a given topography to defined planned situations(for example, fitting a new highway in a landscape,) * Methodsof converting 2-d models into 3-d models (interpretation of heightattribute information, Laser scan data, use of textual height in-formation, etc.) * Checking geometric integrity (duplicate ob-jects, source polygons with forward-backward digitising resulting


in double emission, etc.) * Merging geometry of differing quality,and the inheriting of attributes * Simplification of geometry Whenaiming at the exclusive use of commercial GIS tools for data pre-processing limitations of light versions have to be considered.


An innovative G.I.S. tool for environmental noise manage-mentBernard Miège, Jacques Sampic, Eric PrematCETEThe Technical Studies Centre of Equipment of Lyon (CETE deLyon) has been requested by the Departmental Direction ofEquipment of Isère to build up a Geographical Information Sys-tem collecting all the information related to noise on the 36 kmlong network of Grenoble’s highways. The goal is to establish areference state and to allow for setting and following up a pro-gram and a set of noise action plans according to the EuropeanNoise Directive 2002/49/EC. The achieved database is made upof three topics. Some basic data are given concerning urbaniza-tion around the road network, noise sensitivity in these areas,traffic distribution and history, existing noise shielding devicesclassified by categories (noise barriers, building insulation, roadpavementsoe) with detailed information (size, pictures, oe). Asecond topic shows the results of noise measurements and theextension of these results using a noise propagation model basedon the New French Method for Noise Prediction. This gives rise toa classification of the road network into around 30 homogeneousareas in terms of noise exposure and potential noise abatementmeasures. The last topic describes and assesses some actionplans designed in order to reach a goal of acoustical comfort inthe highways’ vicinity. Since the achievement of this G.I.S. tool,the Departmental Direction of Equipment of Isère has set up animportant program of actions for several years based on the re-sults of this work and consisting in settling efficient acousticalroad pavements on the whole network, building noise barriersand enhancing façade insulation.


Large scale noise mapping in GISFlorian Pfäfflin, Volker DiegmannIVU Umwelt GmbHAcoustic models used in simulation of environmental noise im-pact have become ever larger during recent years. This putsnew demands on software strategies and handling of input data.Often, using existing data from Geographic Information Systems


(GIS) is the only economic approach to create large-scale acous-tic models. IVU Umwelt GmbH and Stapelfeldt Ingenieurge-sellschaft present the integration of a complex suite of programsfor environmental analysis (LimA) into ESRI’s ArcGIS. LimA cal-culation modules are called via the GIS user interface to analyzeacoustic and solar radiation conditions. Direct interaction withthe LimA calculation core is possible to support user requests forinstant calculations. The integration of LimA in a GIS providesadvantages in several aspects of any noise mapping projects, inparticular large-scale. GIS and LimA facilities of defining new ob-ject types and attributes help to simplify customization demands,e. g. define road, rail or industry source objects with specificemission parameters. Calculation results of noise levels andnoise exposure indicators are directly available within the GISfor analyses and presentation. By merging the results with otherinformation in the GIS, further conclusions, e. g. impact anal-yses or determining which kind of road causes dominant noiselevels, can easily be made. The combination of LimA and GIShas been successfully employed in a project for a federal state ofGermany. Noise levels induced by road traffic were calculated ina 20m-raster for an area of 18,000km2. In the calculation, the en-tire road network, totaling 26,000km, terrain and residential areaswere considered.


Experiences with large Scale and City Noise MappingWolfgang ProbstAccon GmbGMany problems arise when noise maps for large areas or for citieswith 100 000s of buildings shall be calculated. A tremendousamount of time and money can be wasted if the description depthof the model is not aligned between different parts of the modelor between noise types. Data acquisition should always take intoaccount the intended use of the model and the sensitivity of theresult in relation to this description depth. But even in the case ofnoise mapping according to the requirements stated in the EU-directive it is worth to think about the usability of the digital modelof a city for other tasks. The value of a city model depends onthe manual work necessary to keep it up to date and to adaptit to changed environmental conditions. If the time schedule fortrains changes each year, it is extremely time saving when theseschedules can be used as spread sheets and be linked to thewhole railway system with all track sections automatically. Withroads the time variation of parameters is not so critical. But eventhere it might be advantageous to store traffic and road data out-side in databases. Interactive Noise Maps that are presented via


Internet are an invaluable information tool. Experience with suchpresentations (e.g. http://www.accon.de) show that many earlierobjections of city administrations about making people too wor-ried about noise problems have no realistic background if someprecautions are taken. Some of these requirements, precautionsand general conditions for the success of a noise mapping projectare presented.


About noise metrics and acoustic impactsMichel MaurinINRETSToday everyone may emphasize the important number of acous-tic indices or noise metrics (Liénard, Smith, Vallet, van den Berg,Maurin 2002). In this paper we try to understand the situation.It is useful to enlarge the acoustic viewpoint and to consider theframework of environmental nuisances, following an examinationof input data families, and of necessary main steps for environ-mental impact indicators building, (Maurin 2003). It is classicalto say (or remind) that noise metrics are referenced to man (assome units do like meter but also lux, foot, thumb, span, ”coudée”oe), here with the p0 constant and the first spectral weightings.But after that there had been a confusion between reference toman and the ”man’s response”, PNdB for instance, and noys andPSIL, oe. Probably a latent confusion, but which truly yielded andyields as many metrological references as particular responses; and then providing the ”babelization” into acoustic units. Thepaper enlightens the confusion between physical, conventionalreferences, and the specific situations, impacts and responses.It recalls the ”major effort” requested in FICON report to connectphysical exposure and impact.

Th. 8:30 Kleber Sonic boom

Numerical Simulation of Sonic BoomFrançois CoulouvratCentre National de la Recherche ScientifiqueA review of sonic boom modeling and numerical simulation is pre-sented, illustrated by outputs of the new software BANGV. Atten-tion is drawn on recent advances in sonic boom modeling. Cou-pling between CFD and atmospherical propagation shows howto supersede the use of Whitham’s function. The influence ofmeteorological variability outlines the lateral behaviour of sonicboom in an upward or downward refracting atmosphere. The risetime as influenced by molecular relaxation is modeled by a shockstructure analysis, which emphasizes a critical value of the shockamplitude related to nitrogen relaxation. Penetration of sonic


boom into the shadow zone is shown to be influenced by effec-tive sound speed gradient, and, in the vicinity of the cut-off, by theground impedance. Focusing associated to large scale manoeu-vers (acceleration, turns) is modeled by the transsonic nonlinearTricomi equation. The question of sonic boom minimization willfinally be briefly discussed. [Work supported by Airbus FranceSAS, Ministère de la Recherche and Commission Européenne -contract SOBER G4RD-CT-2000-00398].


A 10-year statistics of sonic boom carpets based on meteo-rological ERA data and numerical calculationsReinhard Blumrich, Dietrich HeimannInstitut für Physik der Atmosphäre, Deutsches Zentrum für Luft-und RaumfahrtIn the framework of the Sonic Boom European Research Pro-gramme (SOBER) financed by the EU, the propagation of a (pri-mary) sonic-boom emerging from a high-flying aircraft has beeninvestigated. A statistical analysis of the meteorological variabilityand its influence on the sonic boom characteristics, i.e. the soundimmission on the ground, has been carried out. The investiga-tions are based on a full ten-year set of ERA-15 data (years 1984to 1993) of an area in the St.George’s Channel. The sonic boompropagation has been calculated using an advanced ray-tracingalgorithm. The large amount of data has been reduced to shapeparameter which have been analysed using e.g. frequency distri-butions, cross correlations, and cluster analysis. The frequencydistributions of the meteorological data show no significant vari-ation with respect to the daytime and only a few significant varia-tions with respect to the season. The correlation of the acousticand the meteorological parameters show the specific influence ofseveral meteorological parameter on the sonic boom. A classifi-cation of the meteorological data has been carried out in order tobe able to represent the whole sonic boom statistics by means ofa few data sets.


Focusing of sonic boom at caustics induced by flight ma-neuversRégis Marchiano, François Coulouvrat, Jean-Louis ThomasCentre National de la Recherche ScientifiqueA future civil supersonic aircraft faces the formidable challenge toovercome the key environmental issue of reducing sonic boom.The most intense one results from its focusing on caustics (fold orcusp) produced by aircraft maneuvers like transonic acceleration


or turns. The classical modeling consists in introducing diffrac-tion and local nonlinearities around the caustics. The pressurefield is then governed by the nonlinear Tricomi equation for thefold caustic, and by the Khokhlov-Zabolotskaya equation for thecusp caustic. These two equations have been solved numericallyrecently. In order to confirm the theory and validate the numericalcodes, experiments are necessary. An experimental set-up hasbeen built to scale the focusing of sonic boom at 1:100 000 withultrasonic shock waves in a water tank instead of sonic boom inair. The field pattern specific of caustics is synthesized by a largepiezo-electric array using the inverse filter technique. In the vicin-ity of the caustic, the acoustic field is measured and comparedfavourably with the numerical simulations. ’This investigation hasbeen carried out under ’SOBER’ a contract awarded by the Euro-pean Commission, contract number G4RD-CT-2000-00398 andwith financial support of french ministery of research.’


Statistical analysis of N-waves characteristics after propaga-tion in a turbulent mediaSébastien Ollivier, Philippe Blanc-BenonCentre Acoustique - Ecole Centrale de LyonTurbulence plays a role in the propagation and the distortion ofsonic booms but its influence is still not modelled accurately. Onereason for this situation is the lack of controlled experimental datawhich can be used for comparison with theoretical or numeri-cal results. In order to study the influence of turbulence on thepropagation of acoustic N-waves, we conducted laboratory-scaleexperiments. An electrical spark source has been designed togenerate N-waves, and two setups are used to study separatelythe influence of temperature or velocity random fluctuations. Forboth setups the spectrum and characteristic lengths of the turbu-lence have been measured. In this paper, we present the sta-tistical analysis of the mean values and higher moments of theusual parameters used to describe sonic boom signatures (peakpressure, rise time, duration, arrival time) for the waveforms mea-sured after propagation in the thermal or the kinetic turbulence.Mean results are in accordance with previous numerical or exper-imental works. Some examples of random focusing have beenobserved. Since the characteristics of the turbulent media havebeen measured, the data can be also compared to existing theo-retical models. Data show that the increase of the rise time andthe decrease of the peak pressure could be linked to the probabil-ity of occurrence of caustics. This work is partly supported by theEuropean Community (SOBER project, Contract No. G4RD-CT-2000-00398) and by Ministère de la Recherche et des NouvellesTechnologies (decision No. 00 T0116).



Effects of Surface Roughness and Turbulence on Propaga-tion of Shock Waves above a Curved SurfaceQin Qin, Keith Attenborough, Sébastien Ollivier, Philippe Blanc-BenonThe Acoustic Research CentreLaboratory experiments using an electric spark source of acous-tic shock waves have been used to study the influence of refrac-tion and diffraction on propagation of sonic booms. Curved sur-faces were constructed in the anechoic laboratory at ECL to sim-ulate atmospheric refraction effects and a heated grid was usedto generate turbulence. The curved surface was either smoothor rough. The propagation of the shock wave was measuredunder different scattering and refracting conditions using a 1/8”B&K microphone array. The rise time, the peak pressure, and thespectrum of the received acoustic shock have been investigated.The resulting data indicate that surface roughness decreases thepeak sound pressure levels measured in the deep shadow zoneby up to 2.6 dB while the turbulence increases the peak soundpressure levels by 5 dB for the same receiver. In the illuminatedzone, surface roughness increases the peak sound pressurelevel by 1dB and steepens the shock wave whereas turbulencedecreases the peak sound pressure level by 2 dB. These resultsshow that there are significant effects due to ground roughnessand atmospheric turbulence on the propagation of broadbandshock waves in the atmosphere.


Effective Impedance of Rough Sea SurfacesPatrice Boulanger, Keith AttenboroughThe University of HullSonic boom characteristics are likely to be modified during near-grazing propagation above a rough sea surface. Two methodsof calculating the effective impedance spectra of acoustically-hard, randomly-rough, two-dimensional surfaces have been ex-plored. The first method uses the complex excess attenuationspectrum predicted by a Boundary Element Method (BEM) in-put to the classical expression for the sound field due to a pointsource above a smooth impedance plane which is solved sub-sequently for effective impedance roots identified by a windingnumber integral method. The second method is based on ananalytical theory in which the contributions from random distribu-tions of surface scatterers are summed to obtain the total scat-tered field. Measured data for the complex excess attenuationabove 2-D randomly-rough surfaces formed by semi-cylinders


and wedges have been used to deduce effective impedancespectra that are compared to predictions. The analytical the-ory gives relatively poor predictions. On the other hand BEM-deduced effective impedance spectra agree tolerably well withmeasured data. Simple polynomials have been found to fit BEM-deduced spectra for surfaces formed by intersecting parabolascorresponding to sea states from 2 to 7 (roughness heights up to7.5m) for five incidence angles. The overall trends in the polyno-mial coefficients are consistent with the expected decrease in ef-fective impedance with increasing grazing incidence angles androughness scale. It is predicted that the effects of the sea surfaceroughness on sonic boom profiles and rise time are comparableto those due to turbulence and molecular relaxation effects.


Propagation of nonlinear acoustic signals through inhomo-geneous moving mediaPhilippe Blanc-Benon, Vera Khokhlova, Mikhail Averianov, Lau-rent Dallois, Robin ClevelandDepartment of Acoustics, Physics Faculty, Moscow State Univer-sityNonlinear propagation of intense acoustic waves through inho-mogeneous medium is an important problem for many modernapplications including sonic booms in a turbulent atmosphere,explosive waves in a fluctuating ocean, and intense ultrasoundand shock waves in biological tissue. Two different types of in-homogeneities are of importance: scalar inhomogeneities (spa-tial distribution of sound speed and density), for example, dueto temperature variations in the medium or variations in tissuetype; and vector inhomogeneities (spatial distribution of particlevelocity), for example, due to the presence of vortices or flowin the medium. In all of these problems the combined effectsof inhomogeneities, diffraction, and nonlinear propagation deter-mine the peak and average characteristics of the acoustic field. Acomplete theoretical model that includes all the above mentionedphenomena is very complicated for analysis, thus most resultsto date have been obtained for simplified models. In this work,a new nonlinear parabolic wave equation with inclusion of bothscalar and vortex inhomogeneities is presented. Numerical so-lutions of the equation for a fully three dimensional formulation,arbitrary initial periodic or single shock waveforms are described.Typical problems of linear and nonlinear propagation of acousticsignals in media with thermal or vortex inhomogeneities are in-vestigated in order to better understand how the combined effectsof inhomogeneities, diffraction, and nonlinear propagation deter-mine the overall peak and average parameters of the acoustic


field and to distinguish the impact of scalar- and vector-type in-homogeneities on the wave propagation.


Secondary Sonic Boom Modelling for Realistic AtmosphericConditionsLaurent Dallois, Philippe Blanc-Benon, Julian Scott, Uwe Berger,David Allwright, Katarina KaouriCentre Acoustique - Ecole Centrale de LyonThe propagation of the secondary sonic boom is studied using at-mospheric models up to the thermosphere. By solving temporalray equations, the secondary carpet position is investigated. Anamplitude equation including nonlinearity, absorption and relax-ation by various chemical species is coupled to the ray solver inorder to get informations on the amplitude and on the frequencyof the sonic boom at the ground level. Using this propagationmodel and a realistic atmospheric model, the seasonal depen-dencies of the secondary sonic boom are investigated. We ob-served multipath arrivals, directly linked to wind field or 3D inho-mogeneities. Our simulation emphasized also the role playedby the wind structure of the stratopause. Our results are in-tended to be compared to recorded signals of secondary sonicbooms showing low amplitudes and low frequencies. Their rum-bling noise can be interpreted as a summation of sonic arrivalsover different acoustic paths. This work is supported by the Euro-pean Community project SOBER (contract No. G4RD-CT-2000-00398).


Numerical modelling of infrasound propagation at very longdistancePierre-Franck Piserchia, Roger RocheCEACompliance with the Comprehensive Nuclear-Test-Ban Treaty(CTBT) in the atmosphere will be monitored by a worldwide net-work of infrasound stations. The infrasound network will consistof 60 stations equipped with microbarographs in order to mea-sure small changes in the air pressure in the frequency range0.02 to 4 Hz. They are characterized by a good sensitivity (18dB below the minimum acoustic noise), and by a large dynamic(80 dB). By the application of array techniques, it is possible todetermine the direction of pressure pulses caused by small ex-plosions in the atmosphere, as well as shock waves caused bysupersonic aircraft exceeding the sound velocity or meteoritesentering the earth’s atmosphere. To take into account the non-linear phenomena at the source and during the propagation, we


are developing a numerical approach to solve the Euler nonlin-ear equation. In a first step, in the linear domain, this method iscompared with two other numerical modeling approaches basedon the ray tracing technique and the parabolic approach. In ourtest case, the source is on the ground and generates a 1 Pa pres-sure pulse centered at the frequency of 0.1 Hz. We considereran infrasound propagation over a distance of 500 km and an at-mosphere height of 200 Km. In a further step, the source levelwill be increased to study non-linear phenomena.


Low boom airplane design process at Dassault AviationZdenek Johan, Marie-Jose Manfredi, Nicolas Héron, MichelRavacholDassault AviationDassault Aviation as civil aircraft manufacturer studies the fea-sibility of a supersonic business jet and tries to federate in anIntegrated Project (HISAC call2) the European competencies toanswer to the problems of noise, emissions and sonic boom. Oneof the methodologies used to predict this last constraint consistsof using CFD results as inputs for a propagation code based ona ray-tracing algorithm. This method was used in a 5th PCRDproject (SOBER) and is part of a design toolbox dedicated tothe evaluation and/or to the optimization of supersonic aircraft.For the low boom design process, sonic boom wave forms aregiven as input criteria of an optimisation loop. We will presentduring this meeting some results obtained using this approach:sonic boom levels are predicted as a function of aircraft shapes,flight conditions or manoeuvers. The inverse problem will also belooked at. This presentation will also highlight some numericaldifficulties as the pertinence of sonic boom evaluations dependsstrongly on what is extracted from the flow computation. CFDresults have to be assessed according to the numerical schemeor mesh refinement. Trade-offs have to be made when it comesto extracting a pressure distribution from the CFD results: Onewould want to extract the pressure as close to the airplane aspossible since this is the zone where the CFD results have un-dergone the lesser numerical diffusion. Unfortunately, the equa-tions solved for the propagation are not correct in the vicinity ofthe aircraft.



Influence of Liquid Injection at the Nose of a Supersonic Air-craft on the Sonic BoomItham Salah El Din, Anton Lebedev, Thierry Alziary De RoquefortLaboratoire d’Etudes AérodynamiquesThe objective of this study is to investigate the influence of liquidinjection at the nose of a supersonic aircraft on the near field andground pressure signature. An experimental study is performedin a small supersonic tunnel (150x150mm2) at Mach 2 using ageneric model aircraft with a double sweep delta wing. The pres-sure measurements provide the near field signature around theaircraft on a cylinder at a distance 1.7L where L is the length ofthe model. A numerical code is then used to find the extrapolatedsignal at ground level. The method involves two steps: first, thefar field signature corresponding to the near field data set is com-puted using a matching method. Then the theory for non linearacoustic propagation through a non uniform medium is used tofind the ground signature. A significant influence of liquid injec-tion is observed, hence opening a possibility of reduction of thesonic boom. Detailed analysis of the aspect of the signal withand without injection can be found in the final paper.


Sonic boom: ISL studies from the 60’s to the early 70’sArmand Dancer, Pierre NazI.S.L. : Institut franco-allemand de Recherche de Saint LouisSome of the ISL studies made in the past years on sonic boomare presented here. These studies have been initiated during thedevelopment of the supersonic civil aircrafts (in the 60’s) to an-swer the questions: is there a risk for structures or for humanbeings when exposed to sonic boom overpressure? The prop-agation of the sonic boom as a function of the meteorologicalconditions was studied and different simulators for physical ex-periments and physiological observations were built at ISL. Nophysical harm was observed on human beings. However, de-pending on the parameters (peak pressure, rise time, duration...)of the sonic boom, startle reaction may induce psycho-acousticalannoyance.



Determination of physical criteria in the study of the sonicboom loudnessGuy Rabau, Sabine Meunier, Philippe Blanc-Benon, Yvan Mau-relLMA CNRSThe sonic boom generated by an aircraft at supersonic speedis very annoying. Loudness is known to be the most importantparameter for annoyance. Then, the aim of this study is to deter-mine how loudness of sonic boom varies with the physical param-eters of the sound and then how annoyance varies. A sonic boomis a signal with high impulsive feature. Its principal characteristicsare a very large amplitude, superior to 100 Pa, and a very shortduration of the order of few millisecondes with 2 abrupt variationsof amplitude (wave in ” N ”). Our preceeding studies on impulsivesounds have shown that the loudness depends essentially on 2physical parameters that are the energy and the extinction timeof the signal. A simple mathematical law links those two physicalparameters to the global loudness. By analogy with those stud-ies on impulsive sounds we extract specific physical parametersfrom the signals of sonic boom. Perceptive test with the help ofa dedicated cabin specifically built for an accurate restitution ofsonic booms have been done. This allow us to classify differentphysical parameters in order to know which of them are importantfor the perception of the level of sonic booms.


Inverse Filter Optimisation Applied to Sonic Booms Repro-ductionYvan Maurel, Jean-Christophe Béra, Michel SunyachCentre Acoustique - Ecole Centrale de LyonThe aim of this study is to reproduce accurately the waveformsof sonic booms in order to conduct psychoacoustic test on thesubjective evaluation of the impact of this kind of sound upon ourhearing perception. Only the reproduction process will be pre-sented. This application would require infinite bandwidth trans-ducers as the signals involved are extremely impulsive and havea large bandwidth (especially in the low frequencies range). Toovercome this technical limitation, the transducers need to becarefully identified by experimental measurements in order to de-termine their inverse filters. Then the signals can be well pre-processed before applying them on the system input. The goalis to actually measure its acoustic twin on the output with a mi-crophone. An electrodynamic closed-headphone coupled to anacoustic artificial head has been studied. Its transfer function has


been measured by applying different test-signals on the input tominimize measurement errors upon the whole frequency-band (0to 20 kHz). The inverse filter has been computed by two differentnumerical approaches: the direct-inverse method which consistsin directly inverting the transfer function, and the Singular ValueDecomposition method which gives a more precise inverse filterby inverting only the actually measured transfer function (non-inversion of measurement noises). These two analytical meth-ods have been experimentally compared. The high-fidelity con-dition can then be implemented by convoluting the signals by thetemporal-inverse response of the system before sending to thesystem input. The stability of reversibility process has been re-searched.

Th. 8:30 Oberlin Psychoac. methods in musical acoustics

Study of the brightness of trumpets’ sound by analysingimpedance curvesJean-François Petiot, Emilie Poirson, Joel GilbertLAUMIn order to isolate and finely control the influencing variables ofthe timbre quality of brass instruments, we developed a trumpetmouthpiece with a depth that can be easily and continuously ad-justed from ’deep’ to ’shallow’. Using this device and the sametrumpet, we generated a set of instruments with notably differentacoustical behaviour, varying only the internal geometry of themouthpiece. This set of instruments has been evaluated by twoways: - a subjective study of the timbre of the instruments hasbeen carried out via hearing tests with a set of subjects. Thesounds have been generated by a trumpet player and by an arti-ficial mouth. The rating of the brightness of the sounds has beenasked to the subjects. - the input impedance of each instrumenthas been measured. In this paper, we present in which extendinformation extracted from the impedance curves can be used topredict the brightness. For this, the resonance frequencies of theimpedance curve are analysed by principal component analysis.The brightness scores are interpreted by the principal compo-nents via multiple regression technique. As a result, a very goodcorrelation between the rating of the brightness and the positionsin the factorial space is observed.



Psychoacoustical Analysis in Practical Use for Evaluation ofMusical InstrumentsMichael BaltruschInstitut für MusikinstrumentenbauObjektiv evaluation of musical instruments is mainly based onproperties of the transferfunction. From this function parametersare extracted which indicate acoustical properties. So a compar-ison of instruments becomes very simple. Only a subjectiv as-sessment of instruments, concerning acoustical properties, leadsto the appropiate significance of objektiv acoustical parameters.Therefore the parameters are scaled by the ear-relatet proper-ties and perception. Predicted soundproperies derived from thetransferfunction are not allways reliable. Instruments for instanceTongue-instruments, which do not allow to measure the transfer-function, are evaluated using the instrument sound. This contri-bution will present some impressions about the useof psychoa-coustic methods to evalutate musical instruments based on someexamples.


Vibration and Sound of the Indian TablaHelmut FleischerUniversity of the Federal Armed Forces MunichThe smaller instrument of the drum pair in traditional Indian mu-sic is called tabla. It is frequently referred to as the little sisterof the European timpani because it makes also use of a closedkettle. In contrast to the timpani, however, the head of the tablais not homogeneous but consists of different layers, above all acentral ’black patch’. By means of Laser vibrometry the vibra-tion behaviour of a tabla head was investigated. Additionally, theacoustic signals of two tonal strokes, tun and na, were analysedas well by FFT as by an aurally-related analysis software. In rela-tion to a musical instrument, the latter one proved to be superiorto the FFT as it accounts for (1) the critical band resolution of hu-man audition, (2) the extraction of partial tones and (3) the effectof spectral masking. In order to focus on the relevant vibrations ofa musical instrument, an apt psychoacoustically-based analysisrepresents an extremely powerful tool. Especially the simulationof masking is the key to reduce the physical information to itsaurally-relevant core.



Evaluation of Musical Sounds by Means of PsychoacousticalMethodsGunter ZiegenhalsInstitut für MusikinstrumentenbauThe properties pitch and response of musical instruments are de-scribed well by means of known methods of measurement andevaluation. In the case of sound evaluation we don?t find suchresults. Often indirect sizes like frequency response or modeshapes are measured and the sound properties are deducedfrom this sizes. But there are aurally-related signal analysis meth-ods like loudness or sharpness since more then fifteen years. Wecould not find many papers about the application of these meth-ods to musical sounds. One meaning is that the known aurallyrelated methods only operate in cases of technical noises. Thepaper describe some examples of application and compare to theresults of traditionally acoustical measurements.


Auditory Spectrograms and Auditory Contours in MusicalAcousticsPeter DanielCORTEX INSTRUMENTS GmbHConventional Fast Fourier Transform is a useful tool for analy-sis of the physics of musical instruments. For the visualizationof the perceived sounds they fall short as they do not model thetime and frequency resolution and masking properties of the hu-man ear. Requirement for the visualization of musical signalsis a signal analysis modeling the information processing of theear. Auditory spectrograms allow to calculate spectrograms witha time- and frequency resolution according to the human ear.Redundant information can be extracted by time- and frequencycontourization of the auditory spectrogram in analogy to contoursof the visual system. Contours and/or auditory spectrograms canbe resynthesised confirming that only aurally relevant informationwere extracted. The visualization by contours allows intuitively tograsp the important components of a sound. Contributions ofparts of a musical signal to the overall sound can be easily au-ralized by editing and resynthesising them. Resynthesis of timecontours alone allows e.g. to auralize impulsive components sep-arately from the tonal components. Further processing of thecontours determines tonal parts in form of tracks and allows toseparate different streams. The theory starting with the work ofTerhardt will be reviewed and a wide range of applications areshown.



Relationship between Auditory Information Processing andPerceptual Evaluations of Musical InstrumentsMiriam ValenzuelaInPersonIC CorporationA model describing the processes involved in the perceptual eval-uation of musical instruments is presented. The model is basedon a hierarchical model of sensory information processing pro-posed by Terhardt (1992). Accordingly, the information-carryingperceptual attributes that are important for the evaluation of mu-sical instruments are extracted from the sound signal in a seriesof knowledge-based decision processes. Investigations with avariety of musical instruments have emphasized the importanceof the model in finding responses to typical questions of musicalacoustics such as (a) which signal parameters are characteristicfor the sound of a specific instrument (identification) or a familyof musical instruments (recognition), (b) which signal parametersare characteristic for the sound quality of an instrument, and (c)which physical changes in an instrument lead to which audiblechanges. The perceptual attributes responsible for dissimilarityand sound quality judgments of single tones, for example, areprimarily the basic auditory sensations (e.g. sharpness, tonal-ness, openness, fluctuation strength, etc.). The identification andrecognition of single musical tones seem to involve, among oth-ers, the sensations of spectral pitch, virtual pitch and impulsive-ness. Most importantly, the model and the experimental resultsconfirm that there is a close relationship between the process-ing of information in the ear and the evaluation of musical instru-ments. This advocates for an increased application of psychoa-coustic know-how in musical acoustics.

Th. 13:50 Oberlin Sleep, noise and health

Consequences of Chronic Insomnia: Effects on Perfor-mance, Psychiatric and Medical Morbity - an overviewDieter RiemannUniversitaetsklinik fuer Psychiatrie und Psychosomatik Abteilungfuer Psychiatrie und Psychotherapie mit Poliklinik ,Chronic insomnia afflicts approximately 5 to 10% of the adult pop-ulation in Western industrialized countries. It may be triggeredenvironmentally, for example by noise, or it may be secondaryfor example due to psychiatric/organic illnesses or the intake ofprescribed/illicit drugs. It can also occur as primary insomnia,then due to a psychophysiological hyperarousal process. Es-pecially for primary insomnia, the sequelae of the disorder for


performance, psychiatric and medical morbidity have been in-vestigated. Concerning aspects of performance, studies describ-ing the effects of primary insomnia are scarce. It does not seemto lead to increased daytime sleepiness, but rather to the oppo-site. Neuropsychological consequences seem to be only of aminor nature. No data exist that prove definitely that primary in-somnia is accompanied by general psychosocial impairements,though some studies hint to that issue. Studies dealing with theinterplay between primary insomnia and psychiatric diseases, es-pecially depression, have been published increasingly in recentyears and indicate that patients with primary insomnia during thecourse of their disorder are at a hightened risk of developing amajor depression. The picture is less clear with respect to med-ical morbidity: primary insomnia seems to lead to a hightenedutilization of health services and an increased frequency of di-agnostic and therapeutic interventions, especially the intake ofhypnotic drugs. There is, however, no proof yet that primary in-somnia is coupled with an increased frequency of cardiovasculardiseases or a weakening of immune functions.


Exploring the relationship between noise-disturbed sleepand long-term health effectsAlain MuzetCNRSSleep disturbance due to noise is one of the most frequent com-plaints of populations living in noisy areas. Sleep quality can beevaluated by both instrumental and subjective measures. Thephysiological structure of sleep can be quantified by several pa-rameters such as sleep onset latency, sleep duration, time spentin each stage of sleep. Subjective measures are subject’s ownevaluation of sleep quality as well as next day possible after-effects. Annoyance due to ambient noise may be often seen asthe visible part of a greater problem. A certain amount of habitua-tion to noise does exist. If the noise load is not in excess, subjec-tive habituation can occur in a few days or weeks. However, thishabituation is not complete and the measured modifications ofthe autonomic functions, such as cardiovascular responses, stillremained unchanged over long periods of exposure. It is believedthat such long term effect could lead to permanent cardiovascu-lar system impairment. However, to date, there is no evidenceof conclusive effect of chronic exposure to noise during sleep oncardiovascular diseases. The main difficulty is to separate cumu-lative effects of noise-exposure at night from the global exposureto other environmental factors (including noise) over the 24-hourperiod. To our knowledge, no epidemiological study has tried to


specifically answer this question of the effects of noise exposureduring the night compared to the more global daily exposure.


Night noise and health - First Results of the WHO LARESstudyXavier BonnefoyWHO European center for Environment and health, Bonn officeThe World Health Organization’s Regional Office for Europe,Bonn Office has coordinated a large study (LARES) to evalu-ate the health impact of housing conditions in eight Europeancities. Living and housing conditions are the basis for many as-pects that affect residential health: indoor air quality, accidents,noise etc. are only a few of the possible health threats to befound in dwellings. Mental and social health are both affected bythe living conditions but no straightforward mechanisms have yetbeen established. Although such impacts are broadly accepted,the concrete relationship between housing quality and well beinghas so far not been fully understood. First results of the surveypoint out, that noise or ”noise comfort” plays a decisive role inthe general relationship between housing conditions and health.In particular night noise exposure (and therefore noise inducedsleep disturbances) has to be assessed as a serious risk factorfor domestic accidents and as a threat for health, especially forstress related diseases. The design of the LARES study and thefirst findings related to nocturnal noise will be presented.


Effects on health of nocturnal traffic noise - sound level atsubjects’home versus self-reported sleep disturbances -Christian MaschkeFBB - MaschkeRecent epidemiological studies support the assumption thatnightly road traffic noise exposure plays a more fundamental rolein the emergence of health disorders than noise during the day-time - particularly in relation to the cardiovascular and respiratorysystems. It can be assumed that disturbed sleep patterns are animpairment to health in the long run. In these terms, the useful-ness of self-reported sleep disturbances is at the center of thediscussion. An aspect to the discussion is the direct comparisonbetween nocturnal noise exposure (equivalent continuous soundpressure level) in front of the windows of the subjects’ home andthe self-reported sleep disturbances with respect to possible neg-ative effects on health. The presented findings are based on theSpandau Health Survey, which, independent of noise exposure


during the night, also considers self-reported sleep disturbancesas an risk factor for stress related diseases.


Sleep Quality and Nightly Aircraft Noise: Methods and Pre-liminary Results of a Long-term Experimental Field StudyMark Brink, Katja Wirth, Christoph SchierzSwiss Federal Institute of Technology ZurichThe study focuses on the sleep quality impact of aircraft noiseat sleep onset in the evening and before wakeup in the morn-ing. Experiments take place in the subjects homes and run for30 nights each. This experimental period is longer than in mostother comparable studies and allows for the assessment of longterm and habituation effects. 64 subjects are contributing to atotal of 1920 nights. The study is based on a three-factor designwith repeated measures: Timely distribution of noise (evening vs.morning), maximum sound level (Lmax(slow) of 50 vs. 60 dB(A))and number of noise events per night (8 vs. 16). Either at the be-ginning or towards the end of the night, within a 90-minute period,prerecorded aircraft noise events are played back from a loud-speaker in the bedroom. Street traffic noise (matching the soundenergy of 8 x 60 dB(A) aircraft noise events) has been addedto the design and is played back at two evenings and mornings.The nightly sequence of factor combinations is balanced over allsubjects and each subject is administered the same total amountof noise. Physiological as well as self-reported psychological re-action patterns are measured as dependent variables. A non-intrusive recording system for sleep physiology (actimetry, car-diac and respiratory parameters) has been developed. The mea-suring principle is based on the vibrations caused by the cardiacand respiratory system that propagate through the body and arecoupled to the mattress and the bed. These are detected bypressure sensitive sensors installed below the bed-posts.


Aircraft Noise Annoyance at Different Times of DayKatja Wirth, Mark Brink, Christoph SchierzSwiss Federal Institute of Technology ZurichSeveral studies have shown that aircraft noise reactions are re-lated to the time of day: At same noise levels, night-time annoy-ance is above day-time annoyance (e.g. Kastka, 2000; Höger etal., 2002). Furthermore, there exists an annoyance-profile duringthe day, with different annoyance-peaks, being partly indepen-dent from the noise level (e.g. Felscher-Suhr et al., 1996). TheSwiss Noise Study 2000, carried out around the airport Zurichin 2001, confirmed these findings (Wirth et al., 2002, 2003). On


this background, our question is: Which factors influence the vari-ation of the annoyance judgment during the day? On the basis ofthe data of the Swiss Noise Study 2000, answers to this questionare sought. In this survey subjects were asked about the rea-sonability of aircraft noise at different periods of time. It can beshown that the Leq of the corresponding day period plays not animportant role for the reasonability judgment. Especially in theearly morning, subjects seem not to refer to the noise level at thisperiod when rating the reasonability of aircraft noise. The influ-ence of moderator variables is much more important. Possibleinterpretations will be discussed.

Th. 8:30 Arp 1 Vibration from railway lines

The influence of the track on railway induced ground vibra-tionLutz AuerschBundesanstalt für Materialforschung und -prüfungTheoetical and experimental results about the influence of thetrack on railway induced ground vibration are presented. A com-bined boundary - finite element method had been delopped tocalculate the vibrations of different flexible or rigid structures onthe soil. Railway tracks have been thoroughly investigated bythis method. It will be shown what are the differences of the dy-namic track compliances due to additional concrete plates (slabtrack for example) and additional elastic elements such as railpads or ballast mats. Some simpler theoretical models are dis-cussed, too: The structure-soil interaction of an infinite plate (asfirstly discussed accoustically by M. Heckl) and the rail beddedon a chain of masses and viscoelastic springs which is used in-stead of a 3-dimensional track-soil model to calculate the inser-tion loss, the load reduction and load distribution of aelastic ele-ments. Finally, the analysis of the dynamic train-track interactionyields the dynamic axle loads which are the cause of the groundvibrations near the railway line. Railway induced ground vibra-tions have been measured at many places during the last twodecades. Some experimental results are shown to prove the the-oretical consequences and to demonstrate the influence of thetrack on the ground vibration.


Determination of the Static Stiffnes of Resilient Rail Fastenerin Built-in ConditionsFriedrich Krüger, Heinz BeckerSTUVA e.V.The insertion loss of a resilient rail fastener depends on its staticand dynamic stiffnes. In practice the stiffness of one or several


items can be obtained by measurements in a lab using a hy-draulic zylinder. The stiffness in built-in conditions can be differ-ent from the measured stiffness in the lab according to the pre-stressing of the rail and the rail fastener itself. There will be pre-sented some results of measured static (and dynamic) stiffness.The results measured in the lab will be compared with the resultsmeasured in build-in conditions on the line (tunnel and at grade).In addition the chosen facility is described for the measuring ofthe static stiffness.


Vibrations of traffic, from the source to the recipient, theproblem of resonancesGérard RutishauserRustishauser Ingenieurbüro für Bau, Verkehr und Umwelt GmbHVibrations of traffic cause an increasing and more and more re-markable influence over the environment. Most people affectedby clearly perceptible vibrations feel disturbed. Many effects ofresonances are important for the emergence and transmission ofvibrations. The dynamic forces of the wheel-rail-system regard-ing the railway depend on the dynamic interaction of track andground. Particular measures can influence this interaction pos-itively. Such measures are for example ballast mats or elasticunder sleeper mats.The smoothness of the surface and the elasticity of the groundare decisive parameters of the excitations of vibrations regardingthe traffic. A smooth surface is the best measure to limit the im-mission for the immediate surrounding.The transmission of vibrations in a building is also characterisedby resonances. Most important are the resonance frequencies ofa floor. Measuring data out of substantial data bases show someclear conformities to a proposed calculation model. Neverthe-less, the data are widely spread. However, they help to reducethe considerable uncertainty of predictions in the future.


Mitigation of Vibrations Considering Different Types of Train-setsRudolf Liegl, Ulrich MöhlerMoehler + PartnerThe attenuation of structure-borne noise caused by trains mov-ing in tunnels nearby residential areas is essential in order toavoid disturbances in the neighbourhood. The effectiveness ofprotective measures is commonly described in terms of insertionloss and resonance frequency, both - among others - depend-ing on the stiffness of the bearing and the unsprung mass of the


wheelset. The results of current vibration measurements on theone hand indicate reduced vibrational excitation caused by mod-ern lightweight trainsets. On the other hand metrological deter-minations in an existing railway-tunnel show a reduced effective-ness of the protective measures. The results of the measure-ments are presented and compared to calculated values. Withreference to ongoing construction works consequences particu-larly with regard to the dimensioning of protective measures arediscussed.


Aboveground Low Vibration Emission Ballasted Track withConcrete TroughFrank Müller-Boruttau, Volker Rosenthal, Norbert Breitsamterimb-dynamikMeasures for the mitigation of vibration emission from above-ground railway traffic are urgently needed. A newly developedtype of aboveground ballasted track fulfills this need. A solid con-crete trough supports and contains a standard ballasted trackon a ballast mat. The trough confines the ballast. Thus an ex-tremely stable ballast bed is achieved, resulting in a very smooth,high quality track with low emission and next to zero maintenancecosts. The insertion losses due to a) trough bending stiffness, b)ballast mat and mass impedance, c) track quality improvementare explained. A 4 km double track section was installed on thenew Karlsruhe-Basel line next to Baden-Baden. A very demand-ing insertion loss limit had to be met: in the frequency range 10 -50 cyc/s only positive insertion loss values were to be accepted.An overall insertion loss of at least 4,5 dB had to be achieved onwidely varying subsoil conditions. Measurements obtained withregular trains did show that the requirements were surpassed:An insertion loss average of 7,5 dB was achieved. Based onthe measurement results and iSi calculations (imb-dynamik train-track simulation model) predictions were made of achievable in-sertion losses for variations of a) trough properties, b) subgradeconditions, c) ballast mat properties. The resulting mitigations ofvibration and secondary noise level together with very competi-tive costs make this new permanent way a tool adaptable even todifficult environmental conditions.



Development of a New Low Vibration Track System for theVienna UndergroundPaul Berger, Dieter Pichler, Wolfgang UnterbergerFCP - Fritsch, Chiari & Partner ZT GmbHThe Vienna Metro Corporation ”Wiener Linien” uses a vibrationand ground-borne noise attenuating ballast-less track system forits tunnel lines. This system, known as ”Wiener Oberbau” - ”Vien-nese superstructure” - was developed in the 1970s. Its ability toreduce vibrations and ground-borne noise has served the Vien-nese metro well during this period, with only minimal complaintsby residents. However, some disadvantages caused the WienerLinien to consider the development of a new track system: prob-lems were encountered with the durability of the mineralised-woolmats used as an elastic layer between rail slab and foundationbeam, the light-weight sleepers were found to be prone to ma-terial fatigue and the open drainage ditch had to be covered toprevent a safety hazard to firemen and escaping passengers incase of emergency. Therefore the Wiener Linien established aworking group of experts to develop a new ballast-less track sys-tem. This system was to be based on the fundamental principlesand noise and vibration mitigating features of the ”Wiener Ober-bau” but had to avoid its shortcomings. Following a pre-selectionprocedure, the work focused on two ballast-less track types. Forthese two systems, a 300 m long test track was constructed.To determine the system best suited for the Vienna metro thetesting and evaluation programme consisted of an evaluation ofthe construction process, tests with extensive measurements ofdeformations, contact pressures, vibrations and noise (minimumstandard was the noise and vibration attenuating capacity of the”Wiener Oberbau”) and a comparison of the life-cycle costs.


Mass-spring-system installed in a tunnel on the high-speedline Köln-Rhein/MainUdo LenzIng.-Büro Uderstädt + PartnerRailway and tram tracks induce vibrations, which cause structure-borne immissions of noises and vibrations. On the new high-speed track between Cologne and Frankfurt are several tunnels.A tunnel close to St. Augustin was build directly under existinghouses. A mass-spring-system manufactured by the Ed. ZüblinAG was installed in this section for the protection of the adjacentresidents. The tunnelled route is driven on with a speed of 220


km/h. The reinforced concrete slabs of the system have an aver-age thickness of 45 cm. Measurements in the tunnel and in af-fected buildings show the mass-spring-system works effec-tivelyand achieves a successful vibration mitigation. The passage oftrains causes no noticeable vibrations in the affected buildings.(Lecture in German)


Structure-borne noise from railways - a case studyMichel VillotCSTBThe case of the Massena train station in Paris is presented. Inthis station, the train tracks are at ground level and a passengertransit room (going to an underground subway nearby) is locatedright under the tracks, under a thick concrete floor. The inser-tion of a ballast mat between ballast and concrete floor has beenstudied in order to decrease the vibration levels of the floor andthe noise radiated into the transit room. A simplified (infinite) mul-tilayer model ballast - ballast mat - concrete floor has been usedto choose the proper mat. Moreover, it has been possible to makemeasurements before and after inserting the ballast mat and tocompare the experimental insertion loss with the theoretical onegiven by the ballast mat producer.


Vibration Control in a tunnel under an office rehabilitationprojectMarc Asselineau, Stéphane MercierPeutz & AssociésDuring the preparatory work for the Universal 1900 exposition,the line between the Paris railway stations of Austerlitz and Or-say was rerouted into a tunnel under the administrative buildingof the station. A century latter, this building is being turned intoa high class office rental project, and the structure borne noisefrom trains turned from synonym of wealth to nuisance. Due tothe fact that part of the building is preserved it was not deemedpossible to implement vibration control measures on the build-ing. Therefore vibration control had to be implemented underthe track. Due to the restricted loading gauge in this old tun-nel, custom tailored vibration control measures had to be imple-mented. Basically, these called for a resilient mat under and oneach side of the ballast, with careful consideration being given tothe overall thickness as it could eventually foul the loading gauge.This paper describes the preliminary diagnosis prior to designingthe vibration control measures, then the specification and the im-plementation of those measures, and finally the commissioningmeasurements.



Track isolation in a light rail tunnel in downtown BerlinStephan Achilles, Rüdiger WettschureckGuD Geotechnik und Dynamik Consult GmbHPresently, a number of high-profile buildings are being built onBerlin’s Potsdamer Platz, which was previously bisected by theBerlin Wall. Five of the structures under construction are locatedin the immediate vicinity of an existing light rail tunnel. Basedon vibration measurements carried out before construction wascommenced, unacceptable levels of secondary airborne noiseemission were prognosticated. After careful consideration of thepossible construction countermeasures, the costs and the relatedconstruction times, the decision was made to isolate the tracksusing ballast mats (BM). Calculation of the level of structure-borne noise isolation to be achieved with the BM, i.e. their in-sertion loss, indicated that the required level of isolation couldonly be achieved with the use of particularly high-quality elas-tomer materials. In cooperation with the clients, project man-agement and experts, it was possible to negotiate a contract be-tween the five investors for the joint financing and award of con-tract for this track isolation project, and to execute the project inthe third quarter of 2002. This isolation project is outstanding interms of its size (a total of 1,080 m of track with 9 switches and 2crossings). Subsequent to installation of the track isolation mea-sures, follow-on measurements were conducted in the adjacentbuildings, to determine the effectiveness of the isolation system.Based on the results of the vibration measurements in the semi-finished structures it is possible to estimate the expected level ofstructure-borne noise emissions. The results are presented inthis paper.

Th. 8:30 Arp 2 Application of psychoacoustics II

Optimal Coding of Stereo (OCS)Jeroen Breebaart, Steven Van De Par, Armin KohlrauschPhilips Research EindhovenAudio coders aim at transmission and storage bandwidth reduc-tion with a minimum of perceptual quality loss. The informationreduction relies on two principles: removal of redundant infor-mation and exploitation of (perceptually) irrelevant information.For stereo audio material, a limited repertoire of methods to ex-ploit across-channel redundancy and perceptual irrelevancy iscurrently used. Well-known techniques are so-called mid-sidecoding and ’intensity stereo’, which exploit across-channel corre-lation and the human insensitivity to phase differences at high


frequencies, respectively. The result is a two-channel repre-sentation, where the monaural as well as the spatial propertiesare encoded in both channels. In contrast, the OCS algorithmcompletely separates monaural and spatial information by rep-resenting a stereo signal by a monaural channel plus a limitedamount of side information covering the spatial properties. Thisis achieved by analyzing and parameterizing of the perceptuallyrelevant spatial properties of the incoming stereo audio content,combined with the generation of a mono downmix of the two in-put channels. This mono signal can be encoded using any ex-isting coding technique. In addition, the spatial parameters arecoded and combined with the encoded mono signal to form atotal output bitstream. At the decoder side, the mono signal isdecoded and the spatial properties are reinstated according tothe transmitted spatial parameters to form a stereo output signal.Listening tests have revealed that a spatial parameter bitstreamof less than 10 kbits/s is sufficient for high-quality audio, whichleads to a significant bit-rate reduction compared to present-daystereo coding algorithms.


Automatic noise substitution in natural audio signalsJanto Skowronek, Steven Van De ParPhilips Research EindhovenOne key concept in audio coding is to remove signal redundan-cies during the encoding by transforming the signal into a morebit-rate efficient representation. A difficult signal type for someaudio coders are noisy or noise-like audio signals, for instanceunvoiced parts of speech, due to their high entropy. A wave-form description of these noisy signals typically requires a highbit-rate. One possibility to handle this problem is to consider thatthe human auditory system is not able to distinguish between tworealisations of noise, provided that the temporal and spectral en-velopes of both noises are the same. Thus, if the noisy parts ofan audio signal can be automatically classified, only their tempo-ral and spectral envelope have to be encoded and not the sig-nal part itself which is usually more expensive in terms of bitrate.Following this idea, an existing auditory model was adapted in or-der to get a psychoacoustically motivated signal representation.Based on this signal representation, a decision variable was de-rived that was used to identify noisy parts in the time-frequencydomain and replace them with synthesized noise. In this way, au-dio signals were created which allowed an evaluation of the noisesubstitution algorithm in a listening test with several subjects. Re-sults showed that for stationary signals, an audio quality could be


obtained that was comparable to that obtained with an MPEG 1Layer III codec for 96 kbit/sec mono.


Loudspeaker Frequency Response Targets at High Frequen-ciesGerhard KrumpFH DeggendorfFor tuning a loudspeaker box system targets of frequency re-sponse curves are very important. Should the speaker systemhave a neutral tuning with linear frequency response over com-plete frequency range or an increase of high frequency levelto equalize the lower sensitivity of ear? Is then a lower loud-speaker level round 3.5 kHz necessary to reduce the higher hear-ing sensi-tivity caused by ear tube resonance? In order to receivea quantitative answer different tracks with a prepared music se-quence were created on a CD by increasing and decreasing fre-quency response levels at 3.5, 8, 12, and 16 kHz with a Q-factorof 0.7 in steps of 1.5 dB. Ten test persons have estimated thesound of the tracks produced by a loudspeaker box with flat fre-quency response regarding brilliance, sharpness and high fre-quency reproduction with dif-ferent test procedures. Further theyhave choosen the track with the preferred sound. The results ofthe different test methods will be compared and proper frequencyresponse targets will be discussed in consideration of the mea-sured threshold in quiet of the test persons.


Perceptive and objective evaluation of loudspeakersMathieu Lavandier, Philippe Herzog, Sabine MeunierLMA CNRSNormalized measurements used nowadays to compare loud-speakers are only based on a few physical characteristics (fre-quency response, directivity, sensibility,...). The perception of re-produced sound is not considered, although listening is the finalgoal of audio sources. Without tools to assess the perceivedresult of their work, audio professionals are restricted in the im-provements that they could give to their products. Aiming to awider evaluation of reproduced sound, we decided to evaluate apanel of loudspeakers in two parallel ways : objective measure-ments and perceptive ones. The ’objective’ study involves ad-vanced physical measurements and signal processing, such ascorrelation, transfer, and time-frequency analysis which shouldallow a more accurate characterization of the sound radiated byloudspeakers. The ’perceptive” study is based on psychoacousti-cal measurements. Perceptive attributes are determined that are


responsible for our evaluation of an audio source. The goal of ourresearch is to find correlations between the dimensions revealedby these two types of measurements. First, we will present theexperimental protocol chosen. It is compatible with both physi-cal and psychoacoustical measurements as we want to correlatetheir results. It allows to compare different loudspeakers, at thesame position in an usual room, during a unique set of the psy-choacoustical experiment. Secondly, the first results of the twotypes of measurements will be shown. They focus on the studyof the restitution of timbre so the spatial dimension of sound re-production will not be considered here. At the end, both mea-surement will be compared.


Evaluation of the Influence of Various Dispersions on Acous-tical Perception using Experiment DesignVincent Koehl, Etienne ParizetLab. Vibrations Acoustique, INSA Lyon - Bât. 303The aim of this study is to know whether the experiment designmethod can be helpful to evaluate the impact of various disper-sions on acoustical perception or not. The noise stemmed froman electric machine has been recorded with parametric varia-tions. Six parameters, considered as relevant ones and takingthree levels each, have been selected. The nature of those pa-rameters is a mechanical one (axes alignment and dynamic bal-ance, distance between gearsoe). An experiment design hasbeen realized according to Taguchi’s table, in order to estimatethe effects of those parameters with a reasonable number ofsound records. Some questions have then been asked to listen-ers regarding their impressions on the similarity between soundsduring perceptive tests. The effects of parameters have been de-duced from those answers. Using these effects, it should be pos-sible to predict listeners’ answers on any parameters configura-tion. Unfortunately, interactions between parameters have beenhighlighted, so that reliable predictions are not possible at thisstep of the study. Other tests have then been carried out in orderto estimate the effects of interactions. The prediction of listeners’answers becomes a reliable one when taking those additionnaleffects into account. The experiment design method is then anefficient tool to make accurate predictions with a low number ofpreliminary measurements.



Perception of Sounds Radiated From a Vibrating Plate :Comparison of Structural Parameters InfluencesJulien Faure, Catherine Marquis-FavreENTPE-DGCB-LASHIn previous studies, the effects of a plate structural parameterson sound perception have been assessed. These assessmentshave been achieved by studying each one of the structural pa-rameters separately. For each parameter, a sound perceptiontest with at least six stimuli submitted by pairs has been carriedout. This test has led to the representation of the stimuli in theirperceptual space and then to the identification of sound charac-teristics which have played a role on perception. It has also per-mitted one to calculate preference scores for each studied struc-tural parameters value. The main advantage of this approach isthe good accuracy of the perceptual evaluation which has led torelevant conclusions to improve acoustic comfort. Its disadvan-tage is the difficulty of doing comparisons of the relative resultsobtained by the numerous sound perception tests and so the dif-ficulty of concluding about the relative importance of structuralparameters on sound perception. The present paper shows howthis kind of comparison can be possible. A synthesis of the ef-fects of glass and steel plates structural parameters on soundperception will be given. These parameters will be classified inorder of their importance on sound perception. This classificationis helpful in the choice of relevant parameters in the frameworkof sound design or sound quality improvement.


Can we hear the complexity of vibrating plates ?Florence Demirdjian, Dominique Habault, Sabine Meunier,Georges CanévetLMA CNRSThe present work is related to the field of psychomechanics, theaim of which is to establish correlations between acoustical andperceptual attributes of sounds radiated by a vibrating structureand the mechanical parameters of that structure. As a casestudy, we examine the vibrations of a plate excited by a tran-sient point force. This raises an optimization problem for soundsynthesis, since we need to find a compromise between the levelof accuracy (and time cost) required for a valid modeling of theplate, and the perceptual realism of the synthesized sounds re-sulting from the corresponding calculations. Two main aspectsare considered. Firstly, we wished to know whether a plate with avariable thickness can be modeled by a constant-thickness plate


that would be equivalent, from a perceptual point of view, in termsof the radiated sounds. If so, such equivalence would greatly re-duce the complexity of the model. We performed calculationson both types of plates, and ran psychoacoustic tests on therespective sounds to evaluate their similarity. Perceptual crite-ria could be identified, that allowed us to define an ”equivalentthickness”. Secondly, we recorded acoustic impact responses ofactual plates, with constant thickness, and then compared therecorded sounds to the synthetic sounds produced by our model,again using psychoacoustic tests of similarity. These tests helpto determine which parameters are relevant for auditory similarity,and thus provide hints for improving or optimizing our theoreticalmodels.


On the Possible Role of Acoustics for Multimodal Analysisand Recognition of Human Behavior in Smart EnvironmentsGerhard RigollInstitute for Human-Machine-CommunicationThe analysis and recognition of human behavior and action insmart environments is a new challenging discipline in the areaof multimodal interfaces. Smart environments are environmentsthat are capable of interacting with the user or supporting the ac-tions of the user. Examples for such anvironments are e.g. SmartHomes, Smart Offices, or Smart Meeting Rooms. In all those en-vironments, a new trend in human-machine-communication is toenable the user to interact with the devices and the equipmentof the room. For that purpose, the smart environment has to beaware of the presence of the user(s) and to be able to detect theircurrent actions. For instance, if a user in a smart home intends togo to his TV set or points towards it, the smart room should rec-ognize such a behavior and switch on the TV. Also verbal actionsof the user are crucial for detecting his intentions, and therefore,speech recognition in rooms is an important discipline for such aresearch purpose, which automatically involves the use of roomacoustics for recognition. Room acoustics will also play a majorrole in audio-visual tracking of the users, since their position hasto be always known. In this talk, some examples for the possi-ble use of acoustics will be presented in the framework of a re-cently started large EU-funded integrated project on smart meet-ing rooms and the construction of a multimodal meeting browserfor the transcription and exploration of such meetings.



Acoustic simulation in realistic 3D virtual scenesThierry Cathala, Pierre Naz, Patrick GozardOKTAL SEThe simulation workshop CHORALE is used by government ser-vices and industrial companies for multisensor simulations in re-alistic 3D virtual scenes (in the visible, infrared and EM spectrumand now acoustic signal too). For acoustic simulations, the needis, for example, the detection of moving vehicles in 3D scenes.This article describes the acoustic model in CHORALE. The 3Dscene is described by a set of polygons. Each polygon is char-acterized by its acoustic resistivity or its complex impedance.Sound sources are associated with moving vehicles and arecharacterized by their spectra and directivities. A microphonesensor is defined by its position, its frequency band and its sen-sitivity. The purpose of the acoustic simulation is to calculate theincoming acoustic pressure on microphone sensors. CHORALEis based on a generic kernel consisting of functionalities. Thiskernel possesses original capabilities: computation time is nearlyindependent on the scene complexity especially the number ofpolygons, databases are enhanced by precise physical data, spe-cial mechanisms of antialiasing have been developed that enableto consider very accurate details. The ray tracer takes into ac-count the wave geometrical divergence, the atmospherical ab-sorption, the attenuation of sound due to trees and forests, thewind and Doppler effects, the sound diffraction by edges (hill,wall, oe) and the sound wave refraction due to air temperaturegradients. Finally, the article describes a validation test based onthe results of international acoustic detection experiment TG25.


Influence of frequency and magnitude on the perception ofvertical whole-body vibrationMichael Bellmann, Volker Mellert, Hermann Remmers, ReinhardWeberitap GmbH - Institut für technische und angewandte PhysikThe interest in human response to vibration becomes more andmore public because the number of mechanized sources of vi-brations in daily life have enlarged and the number of exposedpersons has increased. Existing standards, for example, ISO2631-1/2 (1997, 1989), refer to sinusoidal (deterministic) exci-tation base on vibration perception in buildings. These standardsaddress, i.e., perception thresholds of whole-body vibrations in alldirections or equivalent-comfort contours. Existing data in liter-ature on the perception of sinusoidal whole-body vibration show


considerable differences to the present standards. However, datafrom different laboratories deviate from each other too, proba-bly due to differences of the used psychophysical measurementmethod. Additionally, incomplete details exist in the literaturefor basic experiments like difference thresholds (JND). Neverthe-less, the benefit of more and better information and knowledgeabout the perception of vibrations allows to improve human re-sponse to vibration models (HRVM) so that ’well-being’ would in-crease and the annoyance experienced from vibrations would bereduced. Furthermore, revised designs and standards could bedeveloped on the basis of improved HRVM and psychophysicaldata. In the present study, some results from vertical whole-bodyvibration perception experiments like perception thresholds, JNDin level and frequency, as well as equal-vibration level contoursare presented. These data are determined with new and reli-able psychophysical measurement methods which minimize theinfluence of measurement parameters on the results. The exper-iments are conducted in the frequency range from 5 to 100 Hz.


Thoughts about Optimization with Subjective Design Goals(with Examples from Acoustics)Peter Költzsch, Volker BormannTechnische Universität DresdenFor a machine, the optimal developmental goal can be estab-lished by the highest efficiency or the least fuel consumption.These criteria can be judged objectively. If there are more crite-ria crucially, then the Pareto Optimization might be an initial stepfor such a solution, or the human has to make a decision basedon his purpose. Compared with acoustics, there are numerousproblems, where the achievement of ’objective optimization’ rests(almost) exclusively on subjective evaluation. A classical problemis the good concert hall acoustics; however, optimal adjustmentof hearing aids, subjective evaluation of walking noise, and thequality of loudspeakers or musical instruments, are further exam-ples. There are methodological questions for such optimizationproblems: What exactly is that subjective criteria for the estab-lishment of the optimal result? Is the subjective evaluation, withregard to design goals, only the expression for a still unfinishedscientifically cognitive process? Which influence does the testperson’s skills (experts, nonprofessionals) have on the optimalresult? Why do the experts’ judgments scatter more frequently,and why do nonprofessionals’ judgments match better? Why dononprofessionals find the same optimal or even better results asexperts do for some optimization problems, with limited knowl-edge or rather bounded rationality? How must nonprofessionals


be asked? Optimizations with subjective design goals are multi-criterially, fuzzily, and they are an example for the problem ofbounded rationality. About those thoughts (questions mentionedabove), a project has been prepared together with psychologists.


Modeling Loudness EnhancementDaniel OberfeldPsychologisches Institut der Johannes Gutenberg-UniversitätMainzOberfeld (2003) proposed that loudness matches to short tonesin the presence of a forward masker can be understood by as-suming that 1. listeners use a weighted average between maskerand target loudness in producing the loudness match and that2. the weight given to masker loudness depends on the per-ceptual similarity between masker and target. Data from exper-iments varying masker-target level difference independently oftarget level supported this view. Loudness enhancement was anon-monotonic function of the level difference. In this paper, aquantitative model based on the above assumptions presented.In the first step, loudness representations for masker and targetare computed according to Zwislocki’s (1965) loudness function.In the computation of the weighted average, masker loudnessreceives less weight if masker and target are perceptually differ-ent. Masker weight is maximum if masker level equals target leveland all other stimulus parameters (e.g., duration) are identical formasker and target. The model uses three free parameters only(maximum masker weight, a parameter representing the effectof masker-target level difference, and a bias parameter). It pro-duced a reasonable fit to data from Zeng (1994) and Oberfeld(2003). Despite its simple structure, the model can account fora) the non-monotonic relation between loudness enhancementand masker-target level difference (the mid-difference hump) b)the so-called midlevel hump (enhancement caused by an intensemasker is greatest at intermediate target levels), and c) the ob-servation that for a given masker-target level difference loudnessenhancement is less pronounced at low than at intermediate andhigh target levels. Implications for intensity resolution are dis-cussed.



Probabilistic Choice Models for Psychological ScalingFlorian Wickelmaier, Christian SchmidAalborg UniversityWhen scaling perceived magnitudes, it is common practice toemploy direct rating scales, asking subjects either for a numer-ical or a verbal label which is later transformed into a number forfurther processing. The validity of scales obtained in this manneris, however, doubtful. Probabilistic choice models provide a pow-erful alternative to direct scaling procedures. Here, the task forthe subject is to choose one stimulus at a time from a pair. Subse-quently, a psychological model of the subject’s decision strategyis formulated, which leads to a ratio scale of the stimuli. Once amodel is specified, standard statistical theory can be used to ob-tain maximum likelihood estimates of the parameter values, esti-mate their covariance matrix, apply various hypothesis tests, andto compare different models with respect to their validity. Untilrecently, the lack of special-purpose software prohibited wide ap-plication of the more sophisticated choice models, such as elimi-nation by aspects (EBA) or preference trees. Now that such toolsare available [Wickelmaier & Schmid, Behav. Res. Meth. In-str. Comp. (in press)], probabilistic choice models could becomemore important in applied research. The modeling approach isdemonstrated using an example from sound-quality evaluation,where the unpleasantness of twelve environmental sounds wasrepresented by a preference tree.

Th. 8:30 Arp 3 Combined noise evaluation

Combined noise effects and noise protection planning - theneed of regulationUlrich MoehlerMoehler + PartnerThe noise protection planning in context with construction of newor existing traffic routes in Germany is considered isolated foreach traffic noise source, the considerartion of combined noisesources ist not regulated. On behalf of some examples, the ef-fects of the isolated consideration of noise sources will be demon-strated and some possiblilties to avoid these will be discussed



Concepts for estimating the total annoyance in residentialsettings containing two noise sourcesRainer GuskiFaculty for Psychology, Ruhr-UniversityAdministrators in industrialized countries are often faced with thetask of estimating the effect of two or more noise sources on the,total annoyance” of residents. Since laboratory experiments donot seem adequate, well controlled field studies are rare, andboth lab and field studies show conflicting results, the admin-istrative task has to be done from the desk, using certain as-sumptions and a theoretical concept. In the past, several modelshave been proposed, e.g., energy summation, annoyance sum-mation, energy difference, and dominant source. The main con-cepts discussed today make at least three assumptions: (1) Therelation between integrated noise levels of a single source andintegrated annoyance judgments of this source is different for dif-ferent noise sources. (2) The annoyance judgment related to aspecific source is indenpendent from the annoyance judgment re-lated to a second source. (3) The noise level of a specific sourcecan be converted to the noise level of a reference source, usingannoyance equivalents. These and other assumptions are dis-cussed in the present paper.


Are different noise sources judged independently from eachother?Katja Wirth, Mark Brink, Christoph SchierzSwiss Federal Institute of Technology ZurichWithin the Swiss Noise Study 2000, an aircraft noise annoyancesurvey has been carried out. In August 2001, 1826 persons in thesurroundings of the airport Zurich filled out a noise annoyancequestionnaire. Several aircraft noise measures were calculatedfor each subject. Even if the main topic of this study was aircraftnoise annoyance, the annoyance of other noise sources (aircraft,road traffic, railway, work) was surveyed, too. Analyses showthat the annoyance judgment of different noise sources are notindependent from each other, even if it was controlled for noisesensitivity. The results of the corresponding path analyses andregression models will be presented. On the basis of the existingliterature about combined noise sources, different interpretationsof these findings will be discussed.



Nocturnal noise from different sources and sleep distur-bances - best practice, background and gaps in knowledge-Christian MaschkeFBB - MaschkeIt is undisputed in noise effect research, that an effect orientatedsummary of sound levels for exposed persons is urgently neededin order to judge complex noise situation correctly with regardswell being or health (Acceptor approach). This also applies tonightly noise exposure and its adverse effects on sleep. Thedata available for source related sleep disturbances is howevermodest by comparison with ”noise annoyance”. In accordancewith the summary model of ’annoyance’, the interaction of nightlynoise sources can be considered by sleep disturbance orientatedeffect-levels. References to the approach arise from studies re-garding noise induced sleep disturbances when the results aresubdivided into different noise sources. The calculated results,however, have to be interpreted with caution since sum effectsare very complex and generally accepted dose response curvesare lacking.


Study of various situations of dominance of combined noisesources (road and railway)Eva Walker, Manon Raimbault, Cora Cremezi-CharletSNCF - Direction de la Recherche et de la TechnologiePrevious studies on the evaluation of combined noise sourcesshow that it is useful to distinguish various classes of domi-nance, according to a difference >5 dB between the levels ofeach source (road or rail). In order to improve the evaluation ofthese situations, several classes of dominance were comparedaccording to the characteristics of their temporal criteria for var-ious periods of the day (graph of LAeq time pattern and severalcalculated acoustic indices). The analyses confirm that the sit-uations of combined noise sources are characterized in variousways depending on their exposure to the noise, since classes ofdominance are not only shaped by the difference in sound level(LAeq) but also by features related to the sound signal itself, suchas the outline, the kind, the duration and the level of emergences.The dominance of railway and road noise are thus fairly deter-mined by this characteristics. On the other hand, the situationswith no dominance have different sub-classes according to theposition of the roadway and the railway facing the building. Theanalysis of these situations is then similar either to the dominance


of railway or road, depending on the various cases of position-ing studied. These results consequently demonstrate the limitsof usual physical descriptors to distinguish various situations ofcombined noise sources.


New indicators for time patterns of combined noise sources(road and railway)Manon Raimbault, Eva Walker, Catherine Lavandier, CoraCremezi-CharletINRETSPrevious studies on combined noise sources show an ambigu-ity in the evaluation of the temporal characteristics of road trafficnoise (continuous but also discontinuous for short periods) ver-sus railway noise (short, abrupt but also recurring for a long pe-riod). To pursue this issue further, listening tests were carriedout in a semi-anechoic room. Sound stimuli were shaped mixingnoises of trains (high speed train, regional and suburban trains,freight) with various road traffic types (with or without truck pres-ence). Both measurements and investigations show that tempo-ral features are more marked in distinguishing train noises. Theassessment of railway noise is characterized by the identificationof a noise source, related to specific time patterns, whereas roadtraffic noise is mainly described through expressions related tospace. The recognition or not of truck presence is then a sec-ond criterion for characterising various categories of traffic. Inthe same time, the study of acoustic descriptors reveals the in-adequacy of the usual codings of noise sources, based on theanalysis of the LAeq time pattern. In view of these results, newtemporal indicators are needed to describe each phenomenonrespectively. However, analysis of the judgements of the timepatterns shows variations between subjects, which are problem-atic for shaping annoyance indicators.


Correcting DNL so it works–betterPaul SchomerSchomer and AssociatesDay-night average sound level (DNL) is commonly used to quan-tify and assess environmental noise. A keystone to noise as-sessment is the dose-response relationship. Typically one pre-dicts something like the percent of a community that is ?highlyannoyed? versus DNL. However, the dose-response relationshipis not an absolute; there is great scatter to the data on which it is


based. In an attempt to reduce the scatter to the DNL data, sev-eral USA agencies (EPA, FAA, etc.) suggested the use of ?nor-malized? DNL?but it was never used. Normalized DNL is the ba-sic DNL value with a number of adjustments added to account forspecific biases, such as community response bias, source char-acteristic and type biases, and time-period biases. This paperreviews and analyzes the concepts inherent in normalized DNLand provides an updated set of normalization factors that can re-duce the scatter to dose-response relationships. Several of thesenormalizations are contained in the new ISO 1996-1:2003.


Poster SessionsPoster Tuesday Poster I

Untersuchungen zur Variation der Klangbildeigenschaftenvon Kopfhörern - Investigations in variations of headphonestone colorationFlorian, M. KönigUltrasone AGHeadphones are working as head-related sound sources at thehuman outer ear. The tone coloration has to be neutral and loud-speaker compatible as recommended at the CCIR 708 for flatdiffuse-field transfer functions (DFTF). Some variation factors in-fluence this transfer functions in a practice use: The individualouter ear or pinna transfer function (OETF) as a part of the head-related transfer function (HRTF) and the principle of the head-phones acoustic reinforcing device in front of the pinna. Exam-ples for this are open/closed or supra-/circum aural headphonesand the speaker placement nearby the auditory canel). Statis-tics on several thousand users of headphones offered signifi-cant more fluctuating tone coloration effects by statments of tomuch or less high frequency range as explained by a ’rough’ or’damped’ sound quality for one created circum-aural, open head-phone for in-front-localisation (HFI) apart from another HFI’s andnormal headphone developments. It was investigated over sevenpersons in an open supra-aural and a closed circum-aural HFI(centric and damped speaker or driver placement) and an opencircum-aural HFI (de-centric speaker placement) and a normalopen, circum-aural headphone (centric speaker placement). Theintention of this work was to research and show the basics of thisextraordinary sound effect in head-related reproduction of sound.So the tone coloration was no subjective testing persons result,but a greater intensive influence of the anatomic pinna construc-tion working together with the sound source placement as a vary-ing acoustic filter unit (compare with a higher standard deviationvalue around 6 kHz).

Poster Tuesday Poster I

A New Method For Elevation Panning Reducing The Size OfThe Resulting Auditory EventsReinhard Gretzki, Andreas Silzleformer: Institut für KommunikationsakustikPanning between two vertically arranged loudspeakers results inan auditory event that can cover almost the whole spanned angle.Additionally, these vertically arranged loudspeakers cause audi-ble comb filtering if listeners are not equally spaced from each


loudspeaker (some centimetres displacement is sufficient). Usu-ally, these effects are reduced by increasing the number of loud-speakers. The present method diminishes the spatial extent ofthe auditory event to a great degree without increasing the num-ber of loudspeakers. Also, the comb filter effects occurring withmisplaced/moving listeners are equally reduced.


Modeling of Silicon Microphone SystemsHeinz-Theo Mammen, Werner JohnFraunhofer IZMBeing an integral part of the product development the simulationof micro systems has become more and more important duringthe last years. It allows to speed up the development cycles formicro systems, because it helps to reduce the number of neces-sary prototypes being manufactured. In the intended contributionsimulation models will be presented, which describe the trans-mission behaviour of micro mechanical silicon condenser micro-phones in the far field. Microphones with omni-directional andbi-directional directivity will be considered as well as microphonearrays. It will be shown how the simulation models can be usedto support the development process already in an early stage.The main aims are to begin with to forecast the behaviour of themicrophones and secondly to realize quickly how constructionalmodifications effect the microphones transmission behaviour inorder to be able to optimise it more tightly focused. Additionallyit is dealt with the demands these two aims make on the mod-elling process itself, before the implementation of the models inMatlab is presented. The implementation was done in a matterthat makes it easy to parameterise and structurally modify themodels.


An operationally applicable tool for sound immission evalu-ation including the atmospheric excess attenuation of soundAstrid Ziemann, Kati Balogh, Andreas Pittelkau, Klaus Arnold,Armin RaabeInstitut für Meteorologie, Universität LeipzigAn important task of the environmental protection is the controland forecast of sound immission near inhabited areas. Here anoperationally applicable method to estimate the sound immissionoutgoing from one sound source and including the atmosphericeffects is presented. This method is used to evaluate the ac-tual ”sonic weather” in comparison to a ”sonic climatology” last-ing over several years. For these purposes a sound propagation


model based on the geometric acoustics is applied. This sound-ray model calculates the excess attenuation due to the refractionof sound rays according to a given thermal stratification and windvector profile in the atmosphere. The needed input data espe-cially for the sound propagation forecast can be provided by at-mospheric models with a highly temporal and spatial availability.Measured data, e.g. from radiosonde measurements, are espe-cially qualified for sonic-climatological investigations. To providesuch a sonic climatology it is necessary to study the different at-mospheric situations separately by the sound-ray model and toaverage the resulting meteorological sound attenuation maps af-terwards. To evaluate the actual sonic weather in comparison tothe averaged sound propagation situation an operationally appli-cable tool was developed. A data base of atmospheric excess at-tenuation maps in a range of 15 km around the sound source wascalculated with the sound propagation model outgoing from 1551characteristic atmospheric structures with different temperatureand wind profiles. The influence of the refracting atmosphere onthe sound immission can be evaluated with the visualization soft-ware MetaVIS.


Aircraft noise prediction based on aircard mix divided into 2groupsThomas Meyer, Matthias Bosse-At DAGA 2001 (published in DAGA report 2002), measurementresults of more than 100.000 aircraft noise events were pre-sented allowing to derive a stable value of noise emission for agroup of aircraft types with similar engine power. This value re-sulted from measuring data with distances between 400 m and1300 m of starting aircraft resp. between 130 m and 530 m oflanding aircraft. The evaluation based on the diminuation of maxi-mum noise levels with the distance as published in AzB (guidanceestablished in Germany for calculation of aircraft noise). The ac-curacy of the evaluated sound power was within the limits of ±1dB(A). The group of aircraft examined in this study covers be-tween 30 and 70 % of the total aircraft mix at all civil airports.An additional study was made recently in order to examine underwhich conditions it is possible to calculate a total noise immissionincluding as a second group the rest of the regarded total aircraftmix allowing a difference of less than ±1 dB(A) in comparisonwith the measured Leq noise immission values of the regardedtotal aircraft mix. It was found that this is possible by adding aconstant value for the sound power of group 2 in relation to group1 independent from different noise emissions and percentages of


the aircraft types included in the second group. The results aregiven based on every of 52 different days within the first half-year2003. The days were chosen with dominating traffic directions.In such days 4 different measuring points for landing resp. 5 dif-ferent measuring points for starting aircraft were included in thestudy.


Aproximation of Costs for improvement programs at in-nercity RoadsPriska Plüss, Peter MohlerAmt für Umwelt und Energie Basel-StadtTraffic noise levels excedes at 30% of all housings along the mainroads, the noise exposure limits. Using the digital noise expo-sure register and the known costs of earlier improvement pro-grammes, the oncoming costs for the improvement of all hous-ings can be estimated with high confidence.


Traffic noise: Standardized messurements versus Calcula-tionPriska Plüss, Peter MohlerAmt für Umwelt und Energie Basel-StadtIn Switzerland the noise exposure level is expressed in an av-erage anual value. Short term mesurements have to be stan-dardised using a comparison between the average traffic and thetraffic during the mesurement. A study shows that this standard-isation leads to exposure levels more insecure than calculatedvalues.


Reactive Noise Control By Means Of Cavities Excited By AirFlowBénédicte Hayne, Jean - Louis TebecENSAMAir traffic gives rise to high noise levels that cause intense annoy-ance to local populations. Although over time aircraft noise hasbeen considerably reduced, the growth in size and the increasein number of aeroplanes bodes ill for noise pollution. Presently,new guidelines and legislation outline more drastic rules : objec-tives defined in 2002 require a 3dB cut in noise pollution. That’swhy manufacturers have kept working for many years on land-ing and take-off noise as well as on aerodynamic and enginenoise. A major breakthrough came for noise reduction with the


conception of double flow engines at high ratio dilution. As re-gards fan noise, it is contained by the use of absorbent materi-als covering the engine housing. This material, chosen becauseof its high-mechanical-performance properties has a honeycombform. Perforation of the outside coating brings about significantimprovement in noise radiation although the feature is still imper-fectly understood. Our study focuses on experimental demon-strations pertaining to the physical characteristics found in thehoneycomb material considered as a Helmholtz type cavity net-work. We demonstrate the reactive nature of these cavities asthey undergo the pressure of sound waves and air flow, a secondmajor factor acting upon the cavities. A test bench makes it pos-sible to measure the acoustic reduction obtained by air flow andto show the feature of reactive noise control when both featuresconcur.


Silencers for exhaust gas stacks of a power stationDietmar Eckoldt, Norbert Rambausek, Jürgen HemsingFraunhofer Institut Bauphysik9 MW oil burning engines are not only producing energy but alsowaste gas and noise. The waste gas stacks are equipped withhigh attenuation silencers. In order to fulfil the acoustic require-ments in the low frequency range too, a combination of reactivesilencers and porous absorbers is installed. The gas temperatureis about 280◦C and the required attenuation is more than 40 dB inall octave bands including the 31 Hz band. The poster presentsthe principle of the solution and the acoustic results measuredboth at the construction site and under operation.


A Compact silencer for heating systemsKarlheinz Bay, Michael Krämer, Peter BrandstättFraunhofer Institut BauphysikThe noise in oil or gas boiler exhaust vents is mainly of a broad-band nature. The burner casing or the firing frequency of enginedriven power stations can add a characteristic resonance andtonal components at low frequencies. In order to meet the acous-tic requirements at the exit of the chimney, silencers are requiredfor these low frequencies. A compact silencer unit, combining aporous and an active sound absorber is presented. The design ofsuch silencers and the attenuation in the low and mid frequencyrange obtained from measurements are discussed.



Study of the acoustic treatment of a workshop of smallhousehold appliancesC. Millard, H. Campagna, Henri-Simon ArbeyDBVibEn prévision de la mise en place de la future législation sur lebruit en milieu de travail, l’étude acoustique d’un atelier a étéentreprise. L’atelier mesure 84 m de longueur et 28 m de largeur,il comprend 3 travées disposées longitudinalement, séparéespar deux allées de 2,2m de largeur.

La simulation la plus efficace a consisté à privilégier le traitementdes zones les plus critiques puis à envisager des actions deréduction du bruit à la source : -mise en place de matériauamortissant sur les goulottes, de carters 3 côtés autour desmoteurs, de caissons insonorisants - modification des cartersexistants - amortissement des chutes de pièces - suppressiondes fuites d’air comprimé.Des gains notables sont observés, puisque le niveau sonore nedépasse 80 dB(A) que dans une zone de l’atelier très réduite.

L’utilisation de la méthodologie d’acoustique prévisionnelle, apermis : i) d’identifier et de quantifier les sources de bruit, ii) deproposer des solutions d’amélioration de l’ambiance sonore, iii)de trouver la solution la plus performante à coût objectif fixé

Référence : C.Millard, Etude acoustique d’un atelier, démarcheméthodologique. Fiche n◦132


Filter Bank Analyser Using Programmable IIR FiltersGaël Nini, Véronique Zimpfer-Jost, Karl BuckI.S.L. : Institut franco-allemand de Recherche de Saint LouisWe have developed a programmable digital filter which is basedon an enhanced IIR algorithm. This filter has a 80 dB dynamics.Its characteristics allow to use it to build a filter bank analyser. Afilter bank analyser is made of contiguous band-pass filters whichprocess the signal and give the level of each band correspondingto 1/3 octave. To analyse a signal in the band 20 Hz - 11 000 Hzwe have used 27 pass-band filters. We have developed a boardincluding 9 filters and I/O to interface the system with a controldevice. We have chosen and programmed a FPGA to do it. Eachfilter has been adjusted to the existing 1/3 octave standards.



Extended Impedance Tube Measurements of Porous Ab-sorbersEnnes Sarradj, Jörn Hübelt, Emad Elsaghir, Peter HolsteinGesellschaft fuer Akustikforschung Dresden m.b.H.Samples of porous absorbers are commonly characterised bytheir absorption coefficient and surface impedance. For mea-surements, standard Kundt’s tube or impedance tube method isused. In the paper, the use of extended measurement techniquesto get the characteristic impedance and the propagation constantis demonstrated. It is shown that to know these parameters is ad-vantageous as they provide information about the material ratherthan the sample.


Transducer emitter-receiver system for a pulsed ultrasonicfluxmeterPhilippe Schmitt, Stéphane FischerIMFS UMR7507 - ULP/CNRSThe knowledge of the velocity fields in the flows and of the me-chanical interactions between a fluid and suspended particlesis a base of many engineer disciplines: chemical engineering,cleansing, sedimentology, biological engineering, fluid rheologyin general. The aim of this project is the development of a fluxme-ter for measuring instantaneous velocity, concentration and gran-ulometry profiles of particle loaded fluids both in ducts or openchannel flows. The first application will be the pollutants flowmeasurement in waste water. The measurement principle of thesystem is based on ultrasonic pulsing in the flow. A prototype wasdeveloped consisting in an ultrasonic transducer, an electronicemitter-receiver device and computer-driven signal processing.The measurement principle is based on the frequency modula-tion (Doppler effect) and the amplitude modulation (Mie theory)of an ultrasonic wave diffused by the suspended particles of thefluid. The paper presents the design features of the system. Itdescribes the block diagram of the front-end electronic and it’sprinciple of operation. Optimisation of power transfer to the trans-ducer in emission and low noise amplification in reception aredetailed. Performances of the whole acquisition chain are given,and the dedicated signal processing used for optimisation of real-time velocity profile are explained. Finally, several applicationsusing this fluxmeter are discussed. Especially instantaneous ve-locity measurements in physic conditions with spectral ambiguity,and possible studies for concentration and granulometry profilesof particles in suspension in the fluid.



Large-scale Impedance tubesWalter Schneider, Michael Leistner, Frank Zickmantel, RichardTippkemperFraunhofer Institut BauphysikThe development of structured and resonance type absorbersrequires new test methods to assess their acoustic propertiessuch as the absorption coefficient. This has been accomplishedby new impedance tubes of a size from 200 x 200 mm up to1600 x 1200 mm cross-section for the installation of large spec-imens. The poster presents the design and implementation ofthe tubes together with the measurement equipment employinga multi-microphone technique and FFT-analysis of the sound sig-nals.


Communication Room Acoustics in Passive Cooled Build-ingsDetlef Hennings(free-lance scientist)Many up to date buildings are cooled during summer without ac-tive cooling devices just through the building’s optimized thermalbehaviour. An essential feature to achieve this is the thermalstorage capability of the building. In most cases passive cool-ing simply requires uncovered concrete ceilings which prohibitsacoustic absorbers at the ceiling. Rooms for human communi-cation (e.g. conference rooms) meeting the passive cooling re-quirements have been studied using acoustics simulation soft-ware. Several measures for speech transition quality (e.g. centertimes) show that the reflective concrete ceiling is an advantagefor communication (as could have been expected). A comparisonof different absorber positions (walls, floor, ceiling) shows that ab-sorbers mounted at walls will lead to a better acoustic quality thanother absorber positions at equal equivalent absorber surface.Thus passive cooling and good acoustic quality for communica-tion can be achieved at the same time. In addition, auralizationsamples of the analysed rooms were checked for their useful-ness in order to make decisions in the planning process easier.A blind test showed that each of the involved persons (all withoutacoustic education) could discriminate the acoustic quality of dif-ferent absorber positions by comparing a set of binaurally aural-ized samples and answering adequate questions. Experimentalverification of the simulation results will be carried out with builtexample rooms in the near future.



Acoustics of Classrooms in brazilian public Schools - ACase Study in CuritibaCarmen Loro, Paulo ZanninUniversidade Federal do Parana - Laboratório de Acustica -Dept◦ de Engenharia MecanicaACOUSTICS OF CLASSROOMS IN BRAZILIAN PUBLICSCHOOLS - A CASE STUDY IN CURITIBA The acoustic qualityof a standard classroom (Standard 23) of the public school sys-tem in the city of Curitiba has been evaluated. This standard isso defined: it has a central circulation aisle, with two classroomsin each side, a total of four classrooms per edification. Eachroom has windows to the outside, and to the internal aisle. Addi-tionally, the aisle has a 6-m high zenithal skylight, together com-posing the building’s main lighting and ventilation system. Theplanning of STANDARD 23 has considered lighting and ventila-tion, but has forgotten the acoustic quality of the classrooms. Inorder to assay the acoustic quality of the classrooms, measure-ments have been performed under several conditions, using theBuilding Acoustics System of Brüel & Kjaer. The measured rever-beration time (RT) of the 4 classrooms for a frequency of 500 Hzwas: 1.65s (classroom empty), 1.15s (20 students in the room),and 0.76s (40 students). According to WHO recommendations,the ideal RT in classrooms should be around 0.6 s. DIN 18041establishes a RT between 0.8 and 1.0 s, to allow for adequateinteligibility. Background noise in an empty room was 63.3 dB(A),a value above the limit established by the brazilian standard ofacoustic confort: 40 dB(A). The reaction of students and teach-ers has indicated that the main source of acoustic disconfort isthe noise generated by the neighboring classrooms.


Effect of ETHICS on the flanking transmission of outer wallsLutz WeberFraunhofer Institut BauphysikExternal thermal insulation composite systems (ETHICS) are at-tached to the outer walls of buildings. They consist of a heat in-sulating layer (mostly mineral wool or polystyrene) which is fixedto the outside of the wall and covered by a plaster coat. Apartfrom their main purpose - the enhancement of heat insulation -ETHICS also change the acoustical properties of the support-ing wall. Not only the direct sound transmission is concerned(the weighted sound reduction index can change from -10 dB to+20 dB), but also the flanking transmission of the wall. Until nowthe knowledge about the flanking transmission of outer walls with


ETHICS is only small. To learn more about the acoustical be-haviour, measurements on various ETHICS in combination withdifferent supporting walls have been carried out. The measuringresults show, that the flanking transmission of massive walls ismuch less affected by ETHICS than the direct transmission. Fromthe measurements, which are confirmed by calculations accord-ing to EN 12354-1, information about the relevant transmissionpathes can be derived. A description of the measurements anda summary of the main results are presented.


Measurement of waste water noise according to EN 14366Lutz Weber, Joachim Mohr, Pascal TellerFraunhofer Institut BauphysikWater installations and, especially, waste water installations canbe very annoying sources of noise in buildings. Therefore, manymanufacturers of waste water systems perform tests to check theacoustical quality of their products. The measurements are car-ried out in a special test facility, which consists of two rooms sep-arated by an installation wall. The system under test is fixed toone side of the installation wall and the resulting sound level pro-duced by a constant flow of water inside of the system is mea-sured in the room behind the wall. Since February 2002 themeasuring method for waste water noise is explicitly specifiedby the new European standard EN 14366 ”Laboratory measure-ment of noise from waste water installations” (draft). The maindifference between the new standard and the previous procedureis the separation of the waste water noise into an airborne anda structure-borne component. In addition, the measuring resultsare related to a standardized (fictitious) installation wall by meansof the structural sensitivity of the real wall in order to get compa-rable results in all test facilities. First practical experiences withthe new standard are reported including a comparison with theprevious measuring method and a discussion of the applicabil-ity of EN 14366 within the frame of the German requirements forinstallation noise (DIN 4109).


Measurements of room acoustic parameters in auditoriumsby simulating the audience by molton clothStefan Birnstingl, Maria Fellner, Franz GrafJoanneum ResearchUntil now several measurements of room acoustic parametershave been published, where concert halls with and without au-dience have been measured. Hidaka/Nishishara/Beranek (JASA2001) and Lorenz/Breuer (DAGA 2003) additionally have used a


special japanese cloth covering the seats for simulation of the oc-cupied state. In this poster similar measurements using anothercloth named molton are published. This cloth is often used forexample in theatre and stage design, it is very easy to get andreasonably priced. Room acoustic measurements are made inauditoriums, music rehearsal rooms and concert halls. Resultsof the occupied, the unoccupied and the ”audience simulated”state are compared.


New room acoustic design concepts for rehearsal roomsHorst Drotleff, Xueqin Zha, Helmut Fuchs, Xiaoru ZhouFraunhofer Institut BauphysikThe philosophy about the acoustics in rehearsal rooms haschanged. As work places for musicians and singers, they shouldnot be built or restored to simu-late a specific auditorium for operaor concert performances, not only because of the totally differentspatial conditions but also of the completely different act-ing en-vironments. The room acoustic environment should ensure thatmusi-cians are able to hear, assess and control their own play-ing or singing while listening and differentiating the sounds of allother members of an ensemble. An often encountered situationis the masking of the sound produced by strings due to the dom-inant brass and percussion instruments. It must also enable anundisturbed communication and interaction between the variousinstruments and the conductor. This may be achieved by a novelconcept incorporating in-novative absorber and reflector moduleswhich damp the low frequency re-sponse of the room, take careof an even distribution of the sounds of the dif-ferent instrumentgroups and, most importantly, improve the transmission to theconductor. A proper room acoustic design may also help to re-duce high aver-age sound pressure levels, which is the inevitableresult of poor music intelligi-bility within an ensemble.


On the use of micro-perforated sails in assembly roomsRoman Wack, Helmut FuchsFraunhofer Institut BauphysikNowadays trends in architecture create buildings which exhibit ahigher ratio than in the past of reflecting surfaces which cannotbe used for acoustic design purposes. Such surfaces are for ex-ample: transparent fronts and walls or ther-mal-active concreteceilings. In order to achieve a reasonable acoustic comfort inthese buildings, a transparent absorber often is needed. Micro-perforated transparent sails have proven very useful to realisean acoustic design in aforementioned rooms. Results of several


successfully completed projects are discussed, among them the”Schlüterhof” in the Deutsches Historisches Mu-seum, Berlin.


Supplementary acoustic measures in the congress centre ofthe Bundesministerium für Wirtschaft und Arbeit, BerlinMichael Leistner, Helmut FuchsFraunhofer Institut BauphysikThe great hall in the main building of the former Kaiser Wil-helm Akademie, to-day’s Federal Ministry of Economics andLabour, had been reconstructed and converted into a congresscentre. During this process, only little attention had been paidto room acoustic design. Consequently, vehement complaintsarose about the poor speech intelligibility. Adequate room acous-tic conditions were obtained by the additional installation of highlyeffective low-frequency and broadband absorbers of a novel con-struction.


Novel room acoustic measures in demanding projects of in-terior design and constructionJochen Renz, Helmut Fuchs, Horst DrotleffRENZ GmbHIn modern interior design one typically encounters a high per-centage of acous-tically reflecting surfaces like large windows orconcrete ceilings. Acoustic broadband damping down to low fre-quencies is essential in such environments in order to achieveadequate acoustic comfort. New concepts of integration of highlyeffective broadband sound absorbers into demanding interior de-sign are shown, be it as single modules or integral parts of wallsor ceilings.


The new StoSilent A-Tec Panel suspended ceiling systemMarkus Lenzer, Helmut Fuchs, Christian HoppeVerotec GmbHA novel suspended ceiling employs open-pore foam made of re-cycled glass. Its surface facing the room is covered by a glass-fibre fleece on which a thin, acoustically transparent, plaster isapplied in order to yield a large, smooth and jointless appear-ance. The acoustic performance of this construction elementcompares favourably with that of conventional acoustic ceilingswith a slight shift of its absorption maximum towards lower fre-quencies. Examples of installations in high-demand communica-tion rooms are discussed.



Improving the acoustics of laminate floor coverings bymeans of damping materialsChristine Patsouras, Klaus Pfaffelhuber, Dimitrios Patsouras,Ernst HotzAKsys GmbHAccording to a preliminary norm of the Association of EuropeanProducers of Laminate Flooring (EPLF Norm 021029-1) the loud-ness should be used to evaluate the quality of a laminate floor bywalking across it. Corresponding to this norm, the laminate floorhas to be excited by a tapping machine and the caused loudnessin the same room has to be calculated according to Zwicker (DIN45631). In the following the results of a laminate floor without anydamping material will be compared to those of the same floor cov-ered on the bottom side with a damping material frequently usedin the automotive industry.


What about standards concerning speech intelligibility inlarge public areas?Claude LegrosUniversité Toulouse II, Laboratoire d’Acoustique (LAUTM)The intelligibility of speech has got a renewed interest by thelast decades, for individual security reasons. In public areas,auditory warning or emergency signals are generally spreadaround by the way of public adress systems. Their qualities arestrongly variable from one to another, and so are the rooms inwhich the messages are sent.

It is not enough to take care of the public adress systemitself as long as the problem is much more wide. One must takeinto account the whole process to estimate the global qualityof the auditory signals. At the beginning of the process, thereis the speaker who has a great importance, according to hispersonal caracteristics such as: speed of speech, accentoe.Standards never say nothing about this aspect of the problem.The electronic arrangement begins to be in standards, in a quitesatisfactorily way. The weak point remains the way the messagesare given to the listeners. The reason is that this process mix alot of parameters not easily standardisable: the loudspeakers,the acoustics of the room and building, the noises which canbe stationary or not, the positions of the listenersoe Recently,some standards have been generated, and the present workwill discuss their terms, in order to show if they are convenientlyapplicable or not. Finally, some proposals will be presented, inorder to make standards easier to apply.



Application of micro-perforated stretched ceilingsChristian Nocke, Catja HilgeAkustikbüro OldenburgIn 2001 a new product based on the theory of micro-perforatedsound absorbers has been introduced. The thin foil of a stretchedceiling has been micro-perforated. Stretched membrane ceilingsare a popular product with regard to modern architecture world-wide since more than 25 years. However, so far only optical andother aspects of the product were generally of interest.

A brief introduction of the underlying theory of micro-perforatedsound absorbers according to D.-Y. Maa will be given. Resultsof independent qualification measurements of various assem-blies will be shown. Furthermore different applications in variousrooms will be presented.

Poster Wednesday Poster II

Speech processing in noise for cochlear implants using amodified channel picking strategyArtmut Meister, Hasso Von Wedel, Martin WalgerJean-Uhrmacher-Institut für klinische HNO-Forschung, Univer-sity of CologneSpeech perception in noise is a crucial problem for hearing im-paired persons. Modern conventional hearing aids offer vari-ous techniques, such as beamforming or one-microphone noisesuppression methods. These techniques are not established incochlear implants (CI). Commercially available CIs have up to 22channels or electrodes, respectively. Various processing strate-gies such as CIS or SPEAK are used. Since not all of the elec-trodes must be stimulated at the same time in order to yield opti-mum speech intelligibility, channel picking strategies choosing alimited number of electrodes are applied. The presentation de-scribes an approach towards speech processing in cochlear im-plants based on a modified channel picking strategy. The exper-iments were conducted using a simulation of the signal process-ing of cochlear implants and were performed with normal hearingsubjects. The stimulation of the cochlea via electrodes was mod-elled with amplitude-modulated sinusoidal carriers of constantfrequencies representing a 20 channel CI. Thus, the technique iscomparable to methods described by McAulay and Quatiery, alsoreferred to as MQ-models. The rationale behind testing the sig-nal processing with normal hearing subjects is that performanceof implanted patients depends on various parameters and com-monly shows large interindividual scatter. The experiments were


conducted with several noise-signals (narrow band, speech-like)and various signal-to-noise ratios. It turned out that the modifiedstrategy reveals improvement of speech intelligibility for narrow-band noises and unfavourable SNRs. Since the method revealsfurther potential for improvement it might be promising for en-hancing speech perception in cochlear implants. Refinement ofthe strategy and evaluation with CI users is subject to subsequentstudies.


The influence of dynamic compression in hearing aids ondirectional hearing in the horizontal planeSharbal Musa Shufani, Martin Walger, Hasso Von Wedel, ArtmutMeisterJean-Uhrmacher-Institut für klinische HNO-Forschung, Univer-sity of CologneThe perception of the direction of sounds depends on several pa-rameters, such as interaural time differences (ITD) and interaurallevel differences (ILD). In order to restore loudness perception adynamic compression is installed in nonlinear hearing aids. Sincecompression alters the signal levels presented to both ears, influ-ences on directional hearing are possible. The effects of com-pression time constants and compression ratios were examinedusing a hearing aid simulator based on a digital signal proces-sor (Motorola DSP 56009 AVM). The two audio-channels of theDSP simulate bilateral hearing aid provision. The acoustic stimuliwere generated via soundcard and processed by the DSP usingdifferent compression parameters (compression ratios of 3:1 and8:1, attack time constants of 2, 20, and 200 ms). Release timewas held constant at 500 ms. Measurements with normal hear-ing subjects revealed decreased lateralisation when ILDs wereused as cues whilst no effect occurred when applying ITDs. Thisheld true for high compression ratios and short attack times andcan be explained with the altered amplitudes of the signals. In anadditional investigation, the position of a sound source was sim-ulated using head-related transfer functions (HRTF), thus con-sidering ILDs and ITDs simultaneously. HRTFs from -60 to +60deg. with steps of 15 deg. were considered. Again, the ability tolocalise sounds was decreased with increasing compression ra-tio and shorter attack time constants mainly due to the effect onthe ILDs. The presentation shows the results of the various ex-periments and discusses outcomes gained with hearing impairedsubjects.



Testsignals and Measurement Procedures for the Evaluationof Modern Hearing AidsHans Wilhelm GierlichHEAD acoustics GmbHIn modern DSP-based hearing aids a variety of signal process-ing procedures can be found. Basically they can be separatedin algorithms, which have long term effects and algorithms whichhave instantaneous effects, e.g. working on syllables of voicesignals. Furthermore most of the procedures work in differ-ent frequency bands. For the evaluation of the system perfor-mance -besides speech signals- different test signals are dis-cussed which more reliably may used in order to evaluate thesystem behavior. Different test signals, providing different speechlike properties will be introduced. Based on the different test sig-nals different analysis techniques can be applied which are differ-ent to the ones used traditionally for hearing aids. The evaluationof hearing aids using the different test signals and procedures willbe shown.


Study On Gearbox Rattle Noise In AutomobilesMuriel Barthod, Jean - Louis Tebec, Jean Christophe PinENSAMAutomobile noise has been considerably reduced as interest inenvironmental concerns as well as a need for more acoustic com-fort have increased. One source of noise in a car, among many,is associated with powertrain. With improvement in engine de-sign, the perception of noise that went formerly unnoticed hasbecome a problem, such as gearbox noise, a well-known sourceof irritation detrimental to vehicle comfort. One such case isthe noise, referred to as ’rattle noise’, caused by fluctuations inengine torque. These fluctuations generate considerable shock,typically irregular in nature being the result of multitudinous fac-tors. The study, explains the mechanical features involved whengear teeth knock, with attention paid to both causes and prevail-ing gear box conditions when this happens, leading to a betterunderstanding of the problem. The first stage entails test benchconceptualizing and materializing to reproduce, (using simplifiedgearboxes), all the angular oscillations coming from the transmis-sion shaft by changing any temporal or frequency characteristicsso as to study the rattle noise in all possible configurations. Thestudy allowed us to monitor the influence of range, frequencycomposition and harmonic component phases involved in theacyclism at the threshold level of rattle. It becomes henceforth


possible to determine at which point rattle occurs in each enginearchitecture in the cinematic transmission chain of each vehicle.


Engine sound noise - Apart from so-called Engine orderanalysisNorio Kubo, Volker Mellert, Reinhard Weber, Jens MeschkeVolkswagen AGImprovement of car engine sound plays a great role in its de-velopment nowadays, especially sporty cars and luxurious cars.Therefore it is necessary to understand the underlying auditoryfeatures of perception to sporty and luxurious sound. Firstly inthis research the meaning of sporty and luxurious impression areinvestigated with a number of test persons. Secondly the time-dependent spectral change of an engine noise due to acceller-ation is investigated. Interesting correlation between a ’sporty’percept and transient properties of the sound pressure signal isobserved. Additionally, a principal component analysis of ques-tionnaire indicates good correlation between well-known station-ary psychoacoustic parameters (loudness, roughness) and theover-all ’luxurious’ impression. The sporty or luxurious impres-sion of an engine noise is additionally investigated with syntheticsounds in which the relevant and time-varying features are sys-tematically adjusted.


Flight Simulations: Influence of Environmental Factors onPassenger ComfortChristian König, Ingo Baumann, Sandra Buss, Nils Freese, SylkeHallmann, Roland Kruse, Volker Mellert, Reinhard WeberCarl von Ossietzky Universität OldenburgThere is a number of factors that influence the passenger com-fort in an aircraft cabin. The influence of environmental variables- noise and vibration, temperature and relative humidity - on pas-sengers comfort is analysed in the EU-Project FACE (FriendlyAircraft Cabin Environment). An environmental comfort index(ECI) to describe the influence of the environmental variableson passenger comfort is important for the manufactures of air-crafts. Because the environmental variables cannot be variedadequately in real flights the effect of varied environmental con-ditions on passengers are examined in a cabin simulator at Wat-ford, UK with 364 test persons. In order to arrange a realisticsimulation there are flight attendances and food services duringthe tests. Each environmental parameter was set independentto three different values. This leads to 27 different environmen-tal conditions. It has been attempted to predict the overall cabin


comfort with a linear model. The parameters of the linear modelare the direct ratings of the environmental variables. [FACE isfunded by the European Community under the ’Competitive andSustainable Growth’ Program, Project Nr. GDR1-2001-40205]


Acoustical Post-Evaluation applied to the neighborhoods ofa small airportMarta R.V Macedo, Jules Ghislain SlamaCentro de Tecnologia, Sala G210During the year 2001, ICAO, the International Civil Aviation Or-ganization has proposed the A33/7 resolution where the multi-disciplinary concept of balanced approach is presented. Then itbecome important to develop new tools to be used for a generalanalysis of the environmental noise impact produced on airportsurrounding populations. The Acoustical Post-occupation Evalu-ation (POE Acoustics) applied to the airports surroundings con-stitutes an appropriate tool which can be used to understand theinterrelation between the many factors that constitute this com-plex matter. The post-occupancy evaluation is compost of aset of actions destined to study a urban or architectural situa-tion. In Acoustical POE, four approaches, technical-constructive,technical-physical, technical-functional and technical-behavioral,are considered, from which it is possible to study the many el-ements that constitute the sonorous environmental impact inan airport surroundings This work, presents a case study forJacarepaguá Airport, a small airport which is situated in the cityof Rio de Janeiro and in which an increasing demand of smallairplanes and helicopters flights exists. In addition, it is beingstudied the possibility of increasing its track from 900 m to 1200m. The noise footprints for the studied area were developed us-ing INM and HNM software’s, considering the noise levels in Ldn

and LA,eq, respectively adopted by the Brazilian aeronautical leg-islation and the NBR - 10151 Acoustics - Evaluation of noise ininhabited areas aiming the comfort of the community - Procedure,willing to identify the affected areas.


Sensibility Studies in Airport NoiseJules Ghislain Slama, Rita De Cássia Cordeiro Nogueira, TéoCerqueira RevoredoCentro de Tecnologia, Sala G210This paper presents the methodology used in Aircraft Noise Sen-sitivity Studies developed by the Environmental Acoustics Groupof COPPE/UFRJ for INFRAERO, the company which manages


66 of the biggest Brazilian airports. Five critical airports, con-sidering the environmental noise impact, had been selected ina previous stage considering the number of people exposed toa level superior to 65dB(A) and the area contained in the curveDNL=65dB(A). For the noise sensitivity studies, the cost func-tion used was the area contained in the curve DNL = 65dB(A).The airport parameters adopted for the studies are the numberof night and day movements for Chapter 2 and Chapter 3 (orchapter 4) airplanes [3]. The relative sensitivity coefficients hadbeen determined studying the variations of the curves areas ver-sus the variation of the airports parameters. The results of thiswork will be used to help decisions on the management of theairports, regarding the noise matter. The softwares used to de-termine the noise curves (Footprints) were the Integrated NoiseModel (INM), HNM (Heliport Noise Model) and the NMPLOT.


Practical applications for in-flight and wind-tunnel testingusing innovative surface microphoneBernard Ginn, Niels Bøgholm, Peter HenningBrüel & KjærThe measurement of flow induced noise in flight and also inwind-tunnels presents a number of problems. The presence ofthe measurement device itself in the flow can create turbulencewhich can interfere with the measurement. Several solutions ex-ist at present including pressure transducers and the insertionof plastic tubing to act as probe microphones. The solution de-scribed here is a circular device with a very low profile denoted asa surface microphone. It can be integrated into a fairing to min-imise obstruction due to air flow. The device has the usual widedynamic range of a traditional microphone and can be equippedwith TEDS to simplify the installation procedure. The paper de-scribes the innovation design of the construction together withresults from practical measurements from in flight and wind tun-nel testing.


Free-field test facilities in the new VW Acoustics CentreGerhard Babuke, Xueqin Zha, Walter SchneiderFraunhofer Institut BauphysikThe Acoustics Centre AKZ occupies 2600 m2 ground area anda building vol-ume of 36000 m3 offering space for two four-wheeldrive roller test beds, a tyre noise test bed, two engine test beds,a drive train test bed and a window test bed for the investigation ofthe attenuation and damping properties of compo-nents. All test


beds are realized as semi-anechoic rooms with innovate Broad-band-Compact-Absorbers as wall linings. The first three of thesetest beds fulfil free-field requirements set by VW with tolerancesof ± 1 dB for 100 Hz to 16 kHz and ± 2.5 dB for 40 Hz to 80 Hzthat even surpass those set by ISO 3745.


Noise reduction and anechoic linings in aeroacoustic windtunnelsAlexander Lecheler, Gerhard Babuke, Peter Brandstätt, DietmarEckoldtFAIST Anlagenbau GmbHThe increasing demand for noise reduction and sound design atvehicles requires adequate test conditions in wind tunnels andtest beds. The Fraunhofer IBP has developed a special broad-band resonant absorber that shows high absorption efficiencydown to 20 Hz with a total lining thickness of only 250 mm and aneven surface. This Broadband Compact Absorber has been ap-plied in silencers and linings at the duct and plenum walls to thewind tunnels of Audi in Ingolstadt, at DaimlerChrysler in AuburnHills and the plenum of the wind tunnel of PSA, Renault andCNAM in Paris. The paper will present the construction, layoutand performance of these new absorbers together with measure-ments showing the freefield conditions achieved in these largefacilities.


Tuning of Musical GlassesThomas Guignard, Vincent MartinEcole Polytechnique Fédérale de LausanneThe glasses composing a musical instrument – such as the glassharp – are tuned by mechanically removing material near thestem. What are the models and methods that could help un-derstand this technique? In a first approach, the glass has theshape of a cylinder, obtained by the rotation of a beam of con-stant width. Resting upon analytic works published in the 80s,the contribution of the vibrational mode of this beam to the modeof the entire glass is identified. Thus, only the vibration of thesingle beam is studied. Then, the tuning process is modeled byan uniform variation of the beam’s width. By using an analyti-cal approach on the one hand and a quite sober finite elementmethod on the other, the percentage of removed material is as-sociated to the diminishing of the beam’s eigenfrequency. Thisfirst step proves to be essential before any further investigationof the subject can be carried out.



Study of the input acoustic impedance of a vibrating cylin-drical shell: consequences on clarinet-like instrument oscil-lationsRuben Pico Vila, François Gautier, Joel GilbertLAUMThe influence of the wall vibrations on the acoustic behavior ofwind instruments is an open question. The first aim of this paperconsists on providing a model of the input acoustic impedance ofa vibrating cylindrical shell. The second aim is to estimate theconsequences of wall vibrations on clarinet-like instruments os-cillations, taking into account the impedance in time-domain sim-ulations. The standpoint is the development of a vibroacousticmodel of the instrument, assuming that it can be approximatedto a simply-supported thin-walled cylindrical shell. This modelprovides an expression of the input acoustic impedance of thevibrating cylinder from the shell motion equation and an integro-modal expansion of the inner pressure field. The wall vibration ef-fect can be interpreted as a small correction of the acoustic inputimpedance of a rigid shell with similar geometrical and mechani-cal features and similar boundary conditions. A simplified modelof clarinet-like instruments permits simulating the self-sustainedoscillations. The input acoustic impedance of the instrument, cal-culated by means of the vibroacoustic model constitutes the nu-merical entrance of the time-domain. Results corresponding todifferent configurations defined by a parametrical study are com-pared with the ’rigid reference’.


Perceptual Spaces of Verbal Attributes Used for Descriptionof Musical Sound Timbre in Czech LanguageOndrej Moravec, Jan StepanekAcademy of Performing Arts in PragueThe words used for description of musical sound timbre were ac-quired. The research was carried out among people with ac-tive relation to the music (instrument players, conductors, com-posers, sound engineers etc.). In written questionnary each re-spondent have stated the words he uses for timbre descriptionand relations among those words. Frequency vocabularies andperceptual spaces of verbal attributes over all respondents andover the selected respondent groups were calculated from ac-quired data. Similarity of vocabularies and spaces and their dif-ferencies in dependency on the respondent group were stud-ied. Twenty five representative verbal attributes were selectedfor non-listening pair dissimilarity test. The selection of attributes


was made with respect to their frequency of occurance, to theirlocation in perceptual space and to differencies among vocab-ularies and perceptual spaces of respective respondent groups.Selected groups of respondents (e. g. bow instrument players,wind instrument players, sound engineers...) have taken part inthe dissimilarity test. Results of the test (dissimilarity matrices)were processed using latent class approach (CLASCAL). Result-ing respondent classes are compared with original respondentgroups. Class perceptual spaces of verbal attributes are alsocompared and discussed.


A specific cabin for restitution of sonic boom : applicationfor perceptive testsGuy Rabau, Philippe HerzogLMA CNRSThe aim of our work is to study loudness and annoyance of sonicboom. For that a specific listening tool must be designed. Thisis necessary because most of the power of the sonic boom is atvery low frequencies, around 3Hz. Such low frequencies are per-ceived by the whole human body, then to assess the annoyanceof sonic booms through listening tests requires to immerse the lis-tener in a field as close as possible to the field in actual situations.Conversely, the strong transients existing in sonic booms lead toa significant spectrum content at higher frequencies. Together,these two aspects put a very high stress on the reproduction sys-tem, which has to reproduce the test signals with a high fidelityfrom very low to high frequencies. The first design of this tool ismade of a closed cabin which walls recovered with absorbing ma-terials, so it can be considered as almost semi-anechoic at highfrequencies. At lower frequencies, a multi-channel loudspeakersystem generates a high volumic velocity by driving loudspeak-ers mounted in the walls of the closed volume, leading to a highpressure down to very low frequencies. Performances of the sim-ulation has been checked through measurements and psychoa-coustic tests.


Principles of Auditory Object Formation: On the Influence ofSpatial Information on Onset DetectionOthmar Schimmel, Armin KohlrauschTechnische Universiteit EindhovenThe ability to segregate and identify sound sources in an auditoryscene comes naturally to most people. In ’Auditory Scene Anal-ysis’, this ability of a human listener to group signal componentsand consequentially separate discrete sources from a complex


mixture of sounds is the focus for research on perceptual streamsegregation, or auditory object formation. By making use of in-teraural disparities in binaural hearing (the main cues for local-ization of a sound source), the auditory system becomes morerobust in grouping signal components. However, from the avail-able literature, it is difficult to decide whether localization cuessupport grouping of signal components, or whether grouping ofsignal components by onset detection is a prerequisite for local-ization of the auditory object. This contribution describes the re-sults of an experiment which explored the principles of auditoryobject formation by quantifying the relations between spatial lo-calization and onset detection. In the experiment, subjects wereasked to temporally adjust a wide-band noise target to fit the me-ter of a regular series of four marker pulses, in a continuouswide-band noise masker. Four different methods for lateraliza-tion (ITDs, ILDs, realistic combinations of ITDs and ILDs, andHRTFs) were applied to the target. After establishing the individ-ual detection thresholds of the target for each spatial condition,the adjustment was performed for several target levels aroundits threshold. The hypothesis, that for a better detection of thetarget’s onset its positioning would be more accurate, was con-firmed, and an influence of spatial information in this paradigmwas established.


Individual differences in integrating loudness over timeBenjamin Pedersen, Wolfgang EllermeierSound Quality Research Unit, Dept. of AcousticsAn experiment was conducted to examine how people integratelevel information to obtain an overall loudness percept. The stim-uli used were broadband noises of one second duration with ran-dom level changes occurring every 0.1 s. Ten normal-hearinglisteners participated in the experiment. Unlike in earlier work us-ing two-interval forced-choice procedures (Ellermeier & Schrödl,DAGA 2000, pp. 169-173), in the present experiments listenerssimply classified a single level-fluctuating noise-burst as beingeither ’soft’ or ’loud’, thus minimizing the role of potential mem-ory effects. Data collected over a few thousand such trials wereanalysed using a statistical procedure that assigns weights tothe ten temporal segments constituting each noise burst. Theweight patterns derived for the participants turned out to behighly individual, the ratios of the temporal weights varying by asmuch as a factor of four. Furthermore, giving trial-by-trial feed-back significantly affected the outcome when compared to a no-feedback condition. These results suggest that temporal integra-tion of loudness cannot be solely explained by sensory factors,


but that judgmental processes will have to be taken into accounteven when describing overall loudness judgments of short level-fluctuating sounds.


Examination of Binaural Activity PatternsWolfgang HeßInstitut für Kommunikationsakustik (Web: www.rub.de/ika)Computational models of localization, which simulate the humanauditory system qualitatively, can be used to evaluate the acous-tical properties of a room. For analysis purposes, head-relatedroom impulse responses of different types of rooms were cap-tured in five degree steps with a rotating dummy head, whichwas placed on a manikin. To be able to predict the acousticalquality of a room, several attributes and characteristics in the 3-dimensional lateralization/activity/time-plots, the so-called binau-ral activity patterns, were investigated and quantified.


The Microphone and Artificial Head Sound Pressure Mea-surementZdenek OtcenasekAcademy of Performing ArtsThe variation of the sound pressure in the same position in frontof loudspeaker in anechoic room was studied for different typesof measurement. Three types of the artificial head, two typesof the microphone and one human head were used. The mea-surements were carried out over the audio frequencies for vari-ous angle among the line connecting the sound source with therecording position and the line normal to the plane of the record-ing microphone membrane or to the plane of head pinna. Thedifferences between results of measurement mentioned aboveare discussed.



Evaluation of Blind Source Separation Methods in AcousticsRoger Boustany, Jérôme AntoniLaboratoire Roberval, CNRS, Université de Technologie de Com-piègneBlind source separation (BSS) is a signal processing techniquewhich consists in recovering a set of unobserved signals (calledsources) given only a set of measured signals (called observa-tions) arising when the sources are mixed by passage throughsome unknown medium. Although the term blind indicates thefact that neither the sources nor the mixing structure are known apriori, several assumptions must be made regarding both. Mostof the existing methods rest on the mutual statistical indepen-dence of the sources and on the linearity of the mixing chan-nel. Moreover, depending on the field of application, the mixturemodel may be either instantaneous or convolutive. Many algo-rithms were developed in order to separate each type of mixture.Our work is organized as follows. First, we present an overviewof the BSS problem and methods for the instantaneous and theconvolutive mixtures. Then, we describe several experimentsconducted on real acoustical signals mixed in an anechoic roomand a reverberant room. Finally, we evaluate the performanceof some BSS algorithms by means of measures of the distortionand the quality of separation.


Effects of Filterbank Compensation for Spectral LimitingPeter DerlethPhonak AGOne main functionality of hearing aids is to amplify an input sig-nal. In practice, the amount of gain applied to the input signalvaries with frequency and time. To prevent discomfort (or evendamage) from the listener, it has to be guaranteed that the levelof the output signal (input signal + gain) does not exceed a cer-tain level, i.e. the output signal has to be limited. In case of amulti-frequency-channel-system with non-overlapping channels,output limiting can be performed in each channel separately. Fora system with overlapping channels, however, the effective lim-iting level for each channel depends also on the amount of gainin the neighboring channels. Methods to compensate for theseeffects introduced by the filterbank are presented and comparedto the standard condition without a filterbank compensation.



Simulation of flow and acoustics in the vocal tractPeter Birkholz, Dietmar JackèlUniversität Rostock, Fachbereich Informatik, Institut für Comput-ergraphikApart from a few exceptions, it is still a common practice to treatspeech production in articulatory models of the vocal tract as apurely acoustic problem. One of the reasons for this is that thereare well established techniques for calculating the sound fieldin the vocal tract which produce remarkable results for voicedsounds. It is still difficult, however, to treat the production ofvoiceless fricatives and plosives in a similar confident way. Thisis due to the fact that these sounds involve fluid motion effectsin the vocal tract which are not accounted for by the acousticequations. To tackle this problem, we extend the familiar lumpedtransmission-line model (TLM) by a new ’resistance’-element,which allows for the inclusion of simple flow-effects, e.g. theBernoulli-effect or shock losses after sudden expansions in thevocal tract, without to disturb the fundamental network structure.Therefore, we derive the equation of motion (one-dimensionalNavier-Stokes equation) from the first principles of fluid dynamicsand apply an appropriate local discretization schema without toneglect higher order terms in the differential equation. We arecurrently implementing a time-domain simulation of the extendedTLM in an effort to synthesize all relevant speech sounds, includ-ing fricatives, in one consistent model.


Intrinsic pitch in German: Examining the overall fundamen-tal frequency contour of the vowelDaniel Pape, Christine MooshammerZAS BerlinThe phenomenon of intrinsic pitch, i.e. the fundamental fre-quency (f0) difference between high and low vowels, has beenfound in a variety of languages (Whalen and Levitt 1995) andis therefore discussed as a universal characteristic. It is widelyagreed that intrinsic pitch can be attributed to differences intongue height. Contrary to that explanation Fischer-Jørgenson(1990) and Mooshammer et al (2001) found for German tenseand lax vowels similar f0 values although the vowels show differ-ences in tongue height. Since in Mooshammer et al. f0 was onlyconsidered at the articulatory defined mid of the vowel, in the cur-rent study we will investigate the whole f0 contour of the vowel forthe same dataset. Results of the current study give evidence thatlax vowels start with a higher f0 than their tense counterparts.


However, standard deviations are considerably high due to vary-ing f0 range. We observed frequently errors of the f0 tracking al-gorithms due to noise at the beginning of the vowel. In addition,the maximum of the f0 contour at the end of the vowel was ofteninterrupted by the following voiceless stop. In order to eliminatethese factors we carried out a second experiment. The f0 rangewas controlled, consonants preceding the vowel were varied be-tween /p,b,f,v,m/ in order to compare the effects of consonantalinduced f0 variation. The consonant following the vowel was al-ways nasal to avoid interruption on the rising f0 contour as in thefirst experiment. For reliable f0 values we recorded EGG simulta-neously. Results of the second experiment will also be presentedat the conference.


Parameter Estimation of Vocal Tract Models for SPEAKFrank Ranostaj, Arild LacroixIAP/Johann Wolfgang Goethe-UniversitätSPEAK is a multimedia system for the investigation and demon-stration of speech acoustics and speech production. The focusis hereby on discrete time acoustical models of the vocal tract.These models approximate the slope of the crosssection of thevocal tract by piecewise homogenous tubes. It is shown for thesemodels, how the crosssectional area is estimated by appropiatealgorithms out of speech signals of vowels, voiced and unvoicedfricatives. Additionally to a good spectral and auditory similaritiyalso a morphological similarity to the vocal tract shape can beachieved. SPEAK can be interactivly controlled by parameterse.g. of the vocal tract model and the results are displayed imme-diately or produced auditive. Especialy there is the possibilty ofvisualizing the crosssectional area and transfer charakteristic ofthe vocal tract model for currently uttered speech simultaneously.


Influence of the Wheel Diameter on the Curve Squealing ofRailway VehiclesEric Cataldi-Spinola, Christoph Glocker, Rossano Stefanelli,Mathias GötschETH Zürich, IMES-Zentrum für MechanikThe noise emission of railway-wheels plays an important role incurve squealing. Therefore, it is important to know the eigen-modes and frequencies of the wheel. Due to abrasion, wheelsneed to have regular maintenance reprofiling and this causes areduction of the wheel-diameter. In the current paper, the effectof diameter reduction on the eigenfrequencies has been studied


numerically using a finite element model of the wheel. The nu-merical results are validated by full scale measurements of theeigenfrequencies and eigenmodes of the wheel. This study hasverified that the frequency associated to a specific eigenform mayconsiderably shift during the life of a wheel. Frequency variationsup to 12 % have been found both numerically and experimen-tally. This indicates that for the investigation of curve squealing,the varying diameter of the wheel should be taken into accountbecause of its influence on the wheel’s vibrational characteristics.


Field Measurements on Curve Squealing - The Influence ofthe Wheel DiameterRossano Stefanelli, Jürg Dual, Eric Cataldi-Spinola, MathiasGötschETH Zürich, IMES-Zentrum für MechanikCurve squealing is an issue getting more and more important forrailway operators. Thus efforts to understand this phenomenonare increasing. In this context ETH Zurich and the Swiss FederalRailways (SBB) initiated a collaboration on this topic. The aim ofthe collaboration is to understand the causes of the phenomenon.An important part of the studies are field measurements of var-ious types. Correlations between occurrence of curve squeal-ing, running speed, running behavior of each boogie and weatherconditions are investigated. Recent research is focusing on thequestion, which modes of vibration and eigenfrequencies are ac-tive during curve squealing. The present essay presents corre-lations between occurrence and frequency of squealing versuswheel diameter. Therefore squealing behavior of driving trailersof suburban trains was monitored. At the same time wheel di-ameter, train speed and weather conditions were recorded. Thisgave the possibility to infer from Finite Element modeling whichmode of vibration was involved in curve squealing. First resultsshow that various modes are involved. Results are discussedrelating to the importance of the occurrence of curve squealing.


Distress caused by high energy impulse noiseSilvester Siegmann, Heinz Brinkmann, Tatjana Burchardt,Thomas Muth, Klaus Siegmund, Elisabeth Borsch-GaletkeUniversitätsklinikum DüsseldorfNoise as a potential cause for dysfunction in the cardiovascularsystem, in particular for heart attack, is still controversial. The ob-jective of this study is to evaluate the association between highenergy impulse and certain specific parameters. 25 men’s re-action to impulse noise between 137 dB (duration 19.3 msec)


and 168 dB (duration 5.4 msec) were analyzed in four differ-ent series of experiments. The following parameters were de-termined: fingerpulse, adrenalin, noradrenalin, and magnesiumin the plasma as well as influencing factors from the psycholog-ical standpoint (annoyance, reasonability, damage to health). Asignificant decrease of the fingerpulse-amplitude is shown after4 seconds with a maximum after 6-8 seconds of noise relatedstress. The strongest decrease is measured at 145 dB (dura-tion 16.6 msec). Concentration of adrenalin declines at any im-pulse level. The level of noradrenalin increases up to 9.2 % at145 dB in comparison to the initial value (p=0.016). Before andafter stress application the magnesium level increases (statisti-cally significant at 168 dB (p= 0.026), statistical trend at 145 dB(p=0.068)). The strongest annoyance is measured at 168 dB anddrops with cumulative distance (p<0,001). A significant correla-tion is shown between estimation of health damage and impulselevel (differences for the answers of both questions are highlysignificant (Chi2-test, two-sided, p<0.001). High energy expo-sure induces changes of biochemical stress indicators depend-ing on the impulse level. Concentration of noradrenalin shows anassociation to the fingerpulse amplitude. Changes of adrenalinconcentration assume an interaction between physical impulsesand psychomental stress disorder.


DNA damage as a result of intensive impulse noiseSilvester Siegmann, Hans-Bernd Prisack, Tatjana Burchardt,Klaus Siegmund, Elisabeth Borsch-Galetke, Hans BojarUniversitätsklinikum DüsseldorfEmployees of numerous industries are exposed to intensive im-pulse noise. Impulse noise may cause changes to isolated cellcultures through temporary compression and decompression.The effects of impulse noise to isolated lymphocytes and lungcells were analyzed. These cells were exposed to 3 impulse lev-els within 30 minutes (Lmax ∼ 170 dB). Total RNA was isolated,amplified, and labeled by an Enzo R© BioArrayTM HighYieldTMRNA Transkript Labeling Kit. Labeled probes were analyzed byAffymetrix chips and the expression was compared with the RNA-profile of PHA-stimulated, unexposed probes. 41.9 % of 12.625known lymphocytal genes were detected. 7.6 % of these geneswere upregulated, 1.8 % were downregulated. Only 22 geneswere 2x upregulated and 4 genes more than 2x downregulatedlike isoformes of the Cytochrome P450 and the Metallothionin-Gene. 44.2 % of 22.283 known genes of the lung cells (distallocated human epithelial cells) were detected significantly. 1.3 %


of these genes were upregulated, whereas 2.7 % were downreg-ulated. 7 genes were 2x upregulated and 33 genes more than2x downregulated. Interestingly, these genes belong to the iso-formes of the Cytochrome P450 and the Metallothionin gene aswell. In conclusion, impulse noise induces cellular reactions com-parable to oxidative stress reaction. In the future, evaluation ofimpulse noise working environment e.g. in the metal processingindustry or by weapon noise in the german federal army shouldconsider potential reactions on the cellular level.

Poster Thursday Poster III

Seismo-acoustic detection of land minesPierre Naz, Thiéry BroglinI.S.L. : Institut franco-allemand de Recherche de Saint LouisThe detection of shallow-buried land mines can be performed bymeasuring the vibrations of the soil. At ISL, we have used anairborne acoustical signal of high level to produce soil vibrations.These vibrations have been measured with the help of a laservibrometer. Because the mine container presents mechanicalcharacteristics which differ from those of the surrounding soil, itmodifies locally the vibration pattern of the soil surface. The firstresults indicate that shallow-buried land mines can be detectedby this non-invasive method.


Validation of Travel Time Tomography by Comparing withConventional in situ MeasurementsDanny Daniel, Klaus Arnold, Astrid Ziemann, Armin Raabe,Manuela Barth, Kati BaloghInstitut für Meteorologie, Universität LeipzigThe method of sounding tomography uses acoustical signalsfrom several external source (transmitter) which are detected withumpteen receivers. By inverting a number of single measure-ments were get information about the spatial distribution of the in-vestigated measurands, whose quality depends on the uncertain-ties at determination of input parameters (travel time, distance)and on the recoverable resolution. In contrast to travel time to-mography ascertaining wind velocities, the air temperatures de-viate systematically from the conventional in situ measurements(e.g. Ultra Sonic Anemometer, Pt100- probes). These deviationsare significant in particular during more intense short wave radi-ation and at high wind velocities. The reasons for this are eithersystematically deviations at the calculation of the meteorologicalparameters from the travel time and/or deficiencies in the con-ventional in situ measurements. The intention is by means ofsystematique experimental inquiries to investigate the reasons of


these varieties in the air temperature. In this context, by compar-ing measurement at a field of view ranging 140 x 160 m2 in a pe-riod of four weeks were researched, how different wind directionand wind velocities have an effect on the resulting air temperatureand how large the differences in observed temperature betweenmeasuring system depending on change of the meteorologicalconditions are, especially during short wave radiation. Further-more it is set up to resolve if during the determination of the airtemperature from the acoustic virtual temperature the value ofthe specific heat has to be adjusted.


Spatial mapping of temperature and wind fields using soundpropagationKlaus Arnold, Armin Raabe, Danny Daniel, Astrid ZiemannInstitut für Meteorologie, Universität LeipzigThe acoustic time tomography is presented as an experimentaltechnique for remote monitoring of spatially averaged meteoro-logical quantities, such as the air temperature and the horizontalwind speed. This ground-based remote sensing technique usesthe nearly horizontal propagation of sound waves in the atmo-spheric surface layer. Here the acoustic travel time tomographywas applied by measuring the elapsed time at defined propaga-tion paths between several sound sources and receivers. Theknowledge of the sound path length has enabled us to determinethe acoustic velocity along the propagation path. Because eachsingle measurement includes information on the properties of theatmospheric layer through which the sound propagates, a tomo-graphic inversion algorithm is able to provide a spatial mappingof meteorological data derived from the measured acoustic pa-rameters. One fundamental difficulty is the separation of the dif-ferent influences on the measured sound velocity. Under the as-sumption of a constant humidity, the effects of the air temperatureand wind vector on the acoustic velocity can be divided. Theretoseveral separation methods are tested and their advantages andlimitations are discussed. Applying these techniques, a horizon-tal section through the atmospheric surface layer with an spatialextension of several hundred meters and a resolution of a cou-ple of decametres for the air temperature and wind speed canbe provided. Depending on the environmental conditions and themeasuring set-up specificities of 0.3 K (temperature) and 0.3 m/s(wind speed) are attainable. Some applications of the acoustictomography during meteorological field experiments are shown.



Excess attenuation of sound due to the atmospheric influ-ence on sound propagationKati Balogh, Astrid Ziemann, Klaus Arnold, Armin RaabeInstitut für Meteorologie, Universität LeipzigThe attenuation of sound is not only based on the spherical di-vergence, but also on atmospheric influences, e.g. the spatio-temporally variable gradients of temperature and wind vector,and on the effects of the different ground surface properties. Inthe presented study the excess attenuation of sound due to therefraction of sound rays propagating trough a vertically strati-fied atmosphere was experimentally and numerically estimatedto quantify the correlation between the acoustic and meteorolog-ical parameters. Thereby, the method of acoustic tomographywas used to measure the travel time and the relative sound ampli-tude of sound signals propagating on distances between 90 and300 m. With these measurements the attenuations for relativesound levels were calculated for different sound paths in differ-ent directions regarding the wind direction. To further investigatethe detected correlation between the meteorological attenuationand the changing vertical gradients of temperature and wind vec-tor the experimental results were compared with the output of asound propagation model. The model traces sound rays througha moving stratified atmosphere. In contrast to the usual applica-tion of the refraction law to the normal of the wave, the presentedmodel uses a refraction law directly developed for the sound raypropagation. It is able to estimate the excess attenuation due tothe atmospheric refraction over a perfectly reflecting or absorb-ing ground surface. Furthermore the estimated meteorologicalattenuation was compared with the usually applied VDI-guideline2714 to estimate its application range under different meteoro-logical conditions.


Analysis of Energy Flow and Energy Densities for One-Dimensional Acoustic FieldsCédric Devaux, Nicolas Joly, Jean-Claude PascalLAUMEnergy methods have proved to be an efficient technique tomodel acoustics or structure vibrations in the high frequencyrange. For any frequency in one-dimensional systems, an ex-act energy formulation is available to model power transfers forstructural acoustics in dissipative media. However, this energy


formulation, based on kinetic- and strain- energy densities, in-volves equations of higher order, more variables, and more com-plex boundary conditions than the usual displacement formula-tion. In the same way, energy densities and structural intensityfields present higher complexity than the displacement field, withcomponents at small space scale (typically the half wave length)or large scale (linked to the dissipative properties of the material).With the objective to select the only components contributingto large scale variations, acoustic energy fields are analyzed interms of forward and backward waves, or propagative and stand-ing components in unloaded portions of one-dimensional struc-tures. To take into account acoustic sources in the large scale ofenergy fields, the different contributions of external sources areanalyzed, for energy densities and structural intensity, in the caseof concentrated loads.


Continuous driving noise measurement equipement : aero-dynamic noise due to the wind drag on microphonesDidier BozeLABO REG. PONTS ET CHAUSSEES AUTUNThe laboratoires des ponts et chaussées network are workingon continuous driving noise measurement equipement. Thisequipement is for people working on publical issues and carac-terises acoustic properties of road materials. This equipementis componed of a special car on which are fixed 3 microphones,among which there is a lateral microphonic system, put as de-scribed in ISO 11819-2 norm, and linked on a data acquisitionsystem. Numerous studies work on interference noise reductionduring the record of noise level created by the wheels on road.The laboratory of Autun studies the aerodynamic noise due tothe wind drag on microphones in a varaible speed flow simu-lating the displacement of a car from 50 to 100 km/h. The ex-periments show the necessity of protecting microphones and thepresence of a turbulent flow which speed profiles and pressuresfield are highly dependent on protection’s Cx. The aerodynam-ics phenomena have a direct impact on produced interferencenoise which change in terms of level and spectral compositionfrom one tested protection to another. In the same time, rac-ing circuit tests show air flow speed gets weaker than car speedwhen closer to protections, hence a relative noise immunity ontemporal measurements. Nevertheless the spectral contributionof these noises is concentrated on low frequencies and can pe-nalize following analyses. So, use of streamlined shape againstwind made of acoustically invisible material, is the solution exper-imented todays.



Analysis of structure borne transmission in a high-speedtrainPascal BouvetVIBRATECSEA (Statistical Energy Analysis) models are used in the railwayindustry for airborne noise analysis in the passenger area. Thesemodels are generally reliable at high frequencies, where trans-mission of airborne noise from the vehicle exterior is the dom-inant transmission path. However, at low and mid frequencies,the structure borne noise transmission path becomes significant.The Energy Flow Method (EFM) is a computationally efficientmethod, by which the results of a Finite Element Analysis (FEA)may be post-processed to form energy flow models. It can beused to study structure borne transmission in coupled structures,based on a modal description of the global structure.This paper presents an industrial application of these techniques,for the analysis of structure borne transmission in a high speedtrain. The standard SEA model for air-borne noise analysis isquickly presented. For structure-borne analysis, the EFM is usedto form an inverse SEA model, which in turns allows to calcu-late Coupling Loss Factors between structural sub-systems. Themethodologies to define appropriate SEA structural sub-systemsare also discussed.


High Order Finite Element Methods for AcousticsSebastien Jund, Stephanie Salmon, Eric SonnendruckerIRMAHigh order finite elements for acoustics. This project is a partof a french-german cooperation DFG-CNRS on ’Noise Genera-tion in Turbulent Flows’. Our objective is to study and predictthe noise generation induced by the flow and to find new noisereduction concepts. Thus we are interested in very precise nu-merical methods for wave propagation. First, we are developingnumerical schemes of high order to solve the second order waveequation on unstructured grids. These schemes should be suffi-ciently compact to obtain a good resolution with a small numberof grid points and designed such that the dispersion and dissi-pation errors are low. We have opted for the use of continuousLagrangian polynomial finite element methods in space (imple-mented for any arbitrary high degree) which are well adapted forunstructured grids, coupled with high order ADER schemes intime.



Vibration of Thin Plates under General Boundary ConditionsRalph HaberkernFraunhofer Institut BauphysikBesides its elastic properties, the boundary conditions of a wallplay an important role for its eigenvibrations. For simplicity’ssake, the thin-plate assumption is made. However, the classi-cal boundary conditions ’free’, ’simple support’, ’clamped’ are notgeneral and not sufficient to catch certain effects that occur inpractice. Especially, the energy dissipation on the boundary isnot contained. This effect requires a general elastic coupling be-tween the wall and its surroundings. Additionally, practical sit-uations motivate the attachment of bars along the boundaries,to account for additional torsional-rod and bending-beam resis-tance and inertia. The nature of a general elastic coupling andbar couplings is explored. The truly local boundary conditions areidentified and a method to determine the eigenvibrations of suchplates is demonstrated. By adaptation of constants the measuredeigenmodes of a wall in the sound-transmission test facility areapproximated.


Calculated and Measured Turbulent Noise in a StronglySwirling Isothermal JetPeter Habisreuther, Oliver Petsch, Henning Bockhorn, HorstBüchnerEngler-Bunte-Institut / Lehrstuhl für Verbrennungstechnik, Uni-versität KarlsruheThe most common technique, used for flame stabilization in in-dustrial combustion devices, is the application of highly swirlinginflows. As such inflows produce at least one recirculation zoneand, in conjunction with that, high velocity gradients and turbu-lence intensities, swirling flows normally constitute a great sourceof turbulent noise. Although it is well known that different types ofswirl generation result in different radial profiles of circumferentialvelocity and, as a consequence, different tendency to enhance orsuppress turbulent motion, few is known on the dependence ofnoise generation with respect to the type of swirl generation andburner outlet geometries. Recent advances in CFD-calculationmethods encourage the application of numerical techniques suchas DNS and LES for the determination of aerodynamic sound. Asa first advance to the problem outlined above, the current inves-tigations show results of LES calculations of a strongly swirlingisothermal flow emerging into a combustion chamber compared


with measured sound pressure values. Spectra of calculated val-ues of static pressure and velocity show a distinct peak value at acharacteristic frequency in the burner nozzle and in the ambientcombustion chamber flow. These self sustaining flow instabilitiescan, similar to frequencies observed in experiments, be corre-lated to global inflow parameters. In addition to that, experimen-tal investigations are carried out to measure noise characteristicsa well as the formation of coherent flow structures, contributingstrongly to the overall noise emissions.


Numerical Experiments on Time Reversal Localization of Im-pulse Sources in an Open SpaceJean-Marc ParotLaRAMA / IFMAThe time reversal principle is a possible way to propagate back-wards to the noise sources. The measured signal is backpropa-gated by computation. According to Fink’s mostly experimentalworks for point-like sources, the reversed wave must focus on thesource. In the present work, we will test this idea by simulatingsimple but non obvious situations: a point source surrounded bybuildings or a spherical radiating surface in an open space. Avery low number of point receivers is used, 3 or 4. Wave frontsredirected back from these transducers, following direct, reflectedor diffracted paths, focus on the source, whether it is seen or keptout of the receiver’s sight. With a conveniently chosen criterion,based on the time duration of the reversed signal, we are able tolocalize the source.


An Educational Model for Acoustic Tomographic ImagingPeter Holstein, Manuela Barth, Armin RaabeSINUS Messtechnik GmbHA model apparatus is presented which has been especially de-signed for educational purposes and experimental testing of to-mographic algorithms. The system is similar to an acoustic to-mographic system which has been developed to observe lo-cal differences in the sound speed in order to recalculate im-ages of physical parameters which influence the sound speedfields under natural conditions. This technique has been ex-tended to a more general environment. The basis is an acousticmulti-channel spectrometer operating in the audio range. Themodel spectrometer completely controls the acoustical experi-ment (emission and reception). The modular approach is imple-mented over several levels including the real-time DSP-software,the driver for the acoustic spectrometer and the data-processing


concept. The controlling software and the algorithmic part havebeen developed within the framework of a general toolbox con-cept for acoustic spectrometers. The extension of the trans-portable model enables frequency- and travel-time scaled experi-ments within the audio and near-ultrasonic range. Different tomo-graphic algorithms can be experimentally verified and optimiseddue to the modular structure, which enables the easy replace-ment of code modules. Possible physical effects which can beinvestigated even under laboratory conditions include the recon-struction of temperature fields and flow fields.


Time Reversal of Ultrasonic Waves through Phononic Crys-talsFrançois Van Der Biest, Gillian Boccara, Arnaud Tourin, MathiasFinkESPCI - LOAPhononic band gap crystals are periodic structures, analogous tophotonic crystals for electromagnetic waves, that forbid propaga-tion of acoustic waves for a certain range of frequencies. Wepresent here time-reversal experiments performed through 2Dphononic crystals consisting of periodic square arrangements ofsteel rods immersed in water. The rod diameter is 0.8 mm whilethe lattice constant is 1.5 mm. Such crystals exhibit a stop bandaround 500 KHz in the [10] direction. Using a transducer workingaround 500 kHz, we send a short pulse into such a crystal. In-side the stop band, no propagating modes exists but tunneling isinvolved. Thus using a receiving transducer array with the samecentral frequency as the source, it is possible to measure a trans-mitted wave which comes from the conversion of the evanescentwaves into propagating modes at the output of the sample. Thiswave is then time-reversed and back-propagated. Both time com-pression and spatial focusing are quantified.


Dust Figures in Kundt’s Tube - Investigations on the Forma-tion of RipplesJulia Moldenhauer, Kai StratmannCarl von Ossietzky Universität OldenburgApart from its technical application, Kundt’s Tube is a well-knowndemonstration experiment in acoustics. It is used to visualizestanding sound waves. Already its inventor August Kundt de-scribed the self- organisation of dust inside the tube to ripplestructures. In the beginning of the 20th century, these structureswere subject of numerous investigations in order to explain theirorigin. Andrade presented in the 1930s an explanation for the


formation of ripples. Visualizing the motion of the air indicatesvortex systems as the cause of these structures, which developaround the dust particles in the sound field. Modern measure-ment and visualization methods support these findings, and be-yond that give new interesting insight into the origin of the dustfigures.


A time domain characterization of porous materials at audiofrequencyNaima Sebaa, Zine El Abiddine Fellah, Mohamed Fellah, WalterLauriks, Claude Depollier, Jean Yves ChapelonNational Institute of Health and Medical Research, INSERM Unit556An audio frequency method of evaluating the acoustic parame-ters of porous materials saturated by air (or any other gas) isdiscussed. The method is based on experimental detection ofwaves reflected and transmitted at normal incidence by the ma-terial. This method is based on a temporal model of direct andinverse scattering problems for the propagation of transient audiofrequency waves in a homogeneous isotropic slab of porous ma-terial with a rigid frame. This time domain model of wave propa-gation takes into account the inertial, viscous and thermal lossesof the medium. The main results is the determination of the per-meability, tortuosity and Young modulus of the porous material.Tests are performed using industrial plastic foams. Experimentaland numerical results, and prospects are discussed.


The Dynamic Radiation Force on Cylinder: Theory and Sim-ulationsFarid G. Mitri, Shigao Chen, Zine El Abiddine Fellah, PhilippeTrompette, Jean Yves ChapelonNational Institute of Health and Medical Research, INSERM Unit556The theory of the dynamic radiation force Yd experienced by aninfinite cylinder is presented. Analytical solutions of the equa-tions for the dynamic radiation force are derived. The equationsenable analytical radiation force dependencies on the acousticfield and medium parameters. The case of compressional andshear waves absorption in the solid material of the cylinder is alsodiscussed. The results of numerical calculations are presented,indicating the ways in which the form of the frequency depen-dence of the dynamic radiation force function Yd for cylindricaltargets is affected by variations in the material parameters of thecylinder. The case of lossless and lossy materials is considered.


The results are of interest in view of the dynamic radiation forceto determine the vibrating velocity of a cylinder immersed in wa-ter or embedded in any lossy medium in order to determine itslocal visco-elastic parameters.


Optimisation of damping layer placement in structuresGoran PavicLab. Vibrations Acoustique, INSA Lyon - Bât. 303The paper addresses the problem of finding an optimum place-ment of damping layers in an elastic vibrating structure. It isshown that the structure-borne intensity divergence can serveas a guiding quantity for this task. The established relationshipbetween the structure-borne intensity and the potential energy ofvibration is further used to make the method operative. The per-formance of the intensity divergence technique is assessed byvirtual experiments done on a beam. It has been demonstratedthat the developed technique gives correct results in a short pe-riod of time.


Meaning of projectile sound by shooting sound emissionsLothar Förster, Rainer Kubicek, Reinhard Müller-There are only two factors that are decisive for the emergence ofthe projectile sound and the area that is covered when the projec-tile sound spreads. These are the speed of the projectile and thelength of its flight path. For various projectile speeds that can beassigned to three different cases the theoretically expected dis-tributions of the projectile sound levels are discussed and thencompared with the actually measured ones.



Determination of the dispersion curves in a noisy shallowwater waveguideDidier CassereauESPCI - LOAWave propagation in a shallow water oceanic environment is usu-ally considered in the general frame of acoustic waveguides. Thedetermination of the waveguide properties without any a prioriknowledge of the environment is well-known to be a difficult task.More particularly, the measurement of the waveguide wave num-bers from a synthetic aperture array requires high-resolution al-gorithm. In the recent past, various algorithms have been pro-posed to determine the wave numbers from experimental or sim-ulated data, like the eigen-matrix pencil method [I-Tai Lu et al.,J. Acoust. Soc. Am. 104 (1), 1998]. In this work, we pro-pose to use our algorithm to calculate from time-domain exper-imental and simulated data the dispersion curves that describethe modal propagation in the waveguide. To this goal, we con-sider a moving source that transmits regularly a pulsed signalreceived after propagation through the waveguide on an arrayof receivers. From the received transient signals, we calculatethe wave numbers for all frequencies inside the bandwidth of thesource-receiver system. This procedure provides to the disper-sion curves corresponding to the different modes in the waveg-uide in the considered bandwidth. The wavenumber inversion isrun on simulated data that can be altered with random noise. Weanalyse the robustness of the inversion algorithm as a functionof the noise level and the length of the synthetic aperture array.We also propose a noise reduction method based on holographicarray processing that correlates the signals measured on all theelements of the receiving array.


Performing Quantitative Ultrasonic Tomography usingWavelets AnalysisPhilippe LasayguesLMA CNRSQuantitative ultrasonic tomography is used to long bones imag-ing. In previous works, we showed that an iterative tool might beused to provide, from reflection tomography, qualitative imagesof the shape of the object, and to provide, from transmission to-mography, quantitative images of the velocity map. Both tomo-graphies are based on ultrasonic propagation in bones, particu-larly perturbed by this high-contrasted heterogeneous medium.


Reflected and transmitted signal are composed of several pack-ages of waves, which had followed various pathways within thecortical shell of long bones. Signal and image processing have alarge important part in the complete process. To improve reflec-tion tomography and shape recognition, we used a novel image-processing tool that improves the resolution and, so, the corticalthickness measurement. This image processing is very simpleand allows us to initialise the transmission tomography, based onthe knowledge of the geometrical properties. The procedure arealso based on the knowledge of the acoustical properties of thebody because the Time-Of-Flight measured on the extracted ul-trasonic signal are related to the useful velocities of the ultrasonicwaves throughout the shell. To optimise our signal processing,we propose a novel algorithm based on the wavelet analysis tooladapted to ultrasonic signals that allow the transmitted signals tobe cleaned and filtered and the useful information to be sepa-rated from the unwanted noise.


Geometrical and acoustical properties identification of high-contrasted bodies using multi-parametric imagingLoic Lemarrec, Philippe Lasaygues, Jean-Pierre LefebvreLMA CNRSWe are concerned by the ultrasonic characterization and iden-tification of the mean-mechanical properties of high-contrastnon-circular tubes such as human long bones. Under condi-tions, scatterer is considered as a weak-heterogeneous and non-absorbing elastic material and we assume that the shell of tube(cortical of the bone) filled by an isotropic medium. In this paper,we present original steps to solve this multi-parametric problem.First, in the forward problem, experimental and numerical (finiteelement method) measurements predict the scattered ultrasonicfield. Second, the inverse problem is solved by a strategy basedon an approximation of the scattering medium by a canonical so-lution. Its scattered field is an analytical modal solution using aRayleigh-Fourier method. The main advantage of this method isthat it can be used even in the case of high impedance contrast.The inversion process is based on the analysis of the discrep-ancy between estimated and predicted fields. The behavior ofthe estimation according to a priori is studied in order to achievea quantitative shape and material properties reconstruction pro-cess. Numerical and experimental results are presented. Origi-nal conclusions will be brought on the contribution of this multi-parametric method to bone tomographic imaging.



Acoustic Wave Propagation in Functionally Graded Material(FGM) CylindersLahoucine Elmaimouni, Jean-Etienne Lefebvre, Tadeusz Gryba,Victor ZhangIEMN - DOAE Université de ValenciennesFGMs are composite materials intentionally designed so thatthey possess desirable properties for specific applications, of-ten to withstand high-temperature-gradient environments whilemaintaining their structural integrity. The mechanical propertiesof cylindrical structure made of FGM vary continuously in themacroscopic sense from one surface to the other, for exampleall ceramic to all stainless steel. In the application of these struc-tures to aerospace, nuclear and automobile industries, analysisof acoustic wave propagation is of great importance. In this ap-proach, we have developed an exact solution to calculate thedispersion curves in FGM cylinders of various geometries. AFGM cylinder made up of stainless steel and silicon nitride isdescribed. The radial variation laws of Young’s modulus, Pois-son ratio and mass density are given, the position-dependentstiffness constants are then deduced. The equations of motionare solved by expanding each mechanical displacement compo-nent using Legendre polynomials and harmonic functions. Fornumerical calculations, the order of the expansion is truncatedto some value N. The solution converges within a very low num-ber N of terms. The numerical dispersion curves are presentedand compared with earlier published results showing an excellentagreement. Advantages and limitations of the approach are alsopresented.


Measurement of the ultrasonic attenuation in viscous fluidsby using a transient techniqueHakim Djelouah, Assia Oudina, Hassina Khelladi, Djema Bel-grouneFaculté de PhysiqueIn the ultrasonic techniques usually used for the measurementsof the attenuation, correcting terms are often introduced in orderto minimise the diffraction effects. Here, we take advantage ofthe particularities of the transient mode in order to deduce the at-tenuation coefficient by using the plane wave model without us-ing any diffraction correcting term. First, a theoretical model ofthe diffraction of ultrasonic waves propagating in viscous media,is developed by using the formulation of the diffracted field un-der the form of a convolution. It is shown that that when a rigid


target of small size is placed near a transducer, the detected re-flected wave consists of three impulses. Only, the first of theseimpulses corresponds to a plane wave coming from the projectionof the target on the surface of the transducer. The others resultsfrom the diffraction from the edge of the radiating source. Themethod principle consists in obtaining the attenuation coefficientafter selecting only the first impulse which corresponds to theplane wave, avoiding thus any corrective diffraction term. Someexperimental results obtained with glycerine, paraffin oil and cas-tor oil at different temperatures will be presented and comparedwith the values obtained by other techniques. The principal ad-vantage of this method is that the measurements are carried outin the near field of a plane transducer, thus avoiding the encoun-tered problems of alignment when the measurements are madein the far field, and the attenuation is determined over a widefrequency band with only one measurement.


Caractérisation de Cibles et Défauts dans les Matériaux parla T.G.D.Rachid LouniFaculté de Physique - USTHBLa détection, la caractérisation et l’identification d’objets ciblesou la localisation de défauts d’homogénéité dans les matériauxou dans les pièces usinées en industrie, occupent une placefondamentale dans les applications des techniques ultrasonores.L’utilisation de la Théorie Géométrique de la Diffraction (T.G.D.)dans ce domaine est une idée relativement récente. Cettethéorie, alliée aux techniques de la spectroscopie ultrasonore,nous a permis de caractériser les dimensions et l’orientation decibles ou de défauts de différentes formes géométriques, us-inés ou insérés dans des matrices d’aluminium. Les résultatsobtenus dans notre travail sont encourageants et montrent toutl’intérêt que peut susciter cette technique de mesure. D’autantplus qu’elle est relativement facile à mettre en œuvre et avec desmoyens à usage courant.


Acoustical measurements in poroelastic materials per-formed with an hybrid ultrasonic methodMohamed Saied, Bernard Castagnède, Alexei Moussatov, VitaliGusev, Vincent TournatLAUMA new hybrid ultrasonic technique is used to generate planarsound waves from powerful low frequency ultrasound being am-plitude modulated. These audio plane waves are then utilized


to perform fine metrological measurements on poroelastic me-dia, such as felt materials. In the present work several config-urations are described both in retrodiffusion and in transmissionwithin the tested material. In any case, one uses a 1/2 inch B&Kaudio microphone for detection and an hand-made piezoelectrictransducer for generation of the ultrasonic amplitude modulatedwaves. In the transmission configuration, dispersion curves havebeen obtained on various felt plates over the 4-40 kHz band-width, and the experimental results have been compared withthe well-known Biot-Johnson-Allard ’equivalent fluid’ theoreticalmodel. For retrodiffusion measurements, the coefficient of re-flection has been measured on the very same plates for a simi-lar bandwidth. These results exhibit some frequency dependentoscillations which are due to constructive and partially destruc-tive interferences within the porous plates. Agreement betweennumerical predictions and experimental data is generally fair,in some cases being excellent. Other ancillary measurementsbased on the Hilbert transform of the transfer function betweenthe incident and the reflected wave will also be presented anddiscussed for some significant results.


Comparative Study of the Weldings NDT Results by Ultra-sounds and RadioscopyAli Badidi Bouda, Rafik Halimi, Ahmed Mebtouche, Mourad Ben-zohra, Amar BenchaalaCentre de Soudage et Controle CSCABSTRACT Non destructive testing of welded joints, which arethe most vulnerable parts in the industrial facilities is requestedmore and more. The techniques of NDT the most used in thesecases is radiography and the ultrasounds. In this article we wereinterested in the non destructive testing of joints welded out ofstainless steel used regularly for certification of levels I and IINDT operators .These parts contain the most current defects likethe cracks, the lacks of fusion which are harmful defects and in-clusions which in general are tolerated until a certain concen-tration. The ultrasonic inspection was carry out by two methodsper contact and in immersion by using transducers of differentfrequencies. These tests showed that the results on the detec-tion and the dimensioning of certain defects can be influenced bychanging the testing method or simply by modifying one or moreparameters of control. This can have serious consequences onthe result of a control. The samples controlled by ultrasoundswere controlled by radioscopy for confirmation and comparison.



Observations of Slow Emergences of an Inertial UltrasonicCavitation Field Produced by Chopped UltrasoundsStéphane Labouret, Jacques FrohlyService de Physique-Electricité, Institut MeuriceThe ultrasonic cavitation behaviour is observed since the begin-ning of the ultrasonic irradiation (frequency = 1 MHz) by meansof both the measurement of both the liquid void rate and theacoustic spectrum which is recorded in the liquid. When the ultra-sound irradiation is performed in chopped mode (silence duration= pulse duration), it is observed 2 regimes called A and B. TheA regime is characterised by a slow increase of the void rate andthe presence of harmonics and under-harmonics in the acousticspectrum, and corresponds essentially to the presence of sta-ble cavitation bubbles. The B regime that follows the A regime,displays a strong increase of the void rate and a broadband cav-itation noise in he acoustic spectrum. The B regime correspondsto an inertial cavitation field. The transition from the A regime tothe B regime occurs with a delay that depends on the choppingfrequency. Furthermore, the transition duration is short (relativelyto our measurement resolution, round to 1 second) for the major-ity of the chopping frequencies considered. Notwithstanding, wewill present examples for which the transition develops over du-rations up to tens seconds.


Suppression of intra-plate echoes when focusing through atitanium Fabry Perot: comparison between inverse filter andtime reversal cavityFrancois Vignon, Alejandro Saez, Jean Francois Aubry, DidierCassereau, Mathias FinkESPCI - LOAWhen focusing through plates or tubes the presence of multi-ple interfaces induces reflected wave fronts that follow the mainwave front. Adaptive focusing techniques can be used to cancelthe echoes. For that purpose, two linear arrays of transducershave been placed on each side of a titanium plate acting like anultrasonic Fabry-Perot. Three propagation operators have beenacquired: the transmission H from one array to the other and thetwo reflection operators K1 and K2 acquired by each array.Theoretically, the echoes can be suppressed by using a completecavity with transducers surrounding the plate. In this experiment,the two arrays are recording the field along a sufficient surfaceto cancel the echoes (20dB decrease). Parallel to this work,thanks to the inversion of the H matrix, the echoes have been


cancelled by using the inverse filter technique. Thus, the inversefilter achieves echoes cancellation by using only the transmittedfields, whereas time reversal also needs the reflected fields. Sig-nals emitted with both techniques are compared in order to ex-plain how the focusing is achieved in both cases. In fact, transmitand reflected wave fronts are related by the Stokes relations, ex-plaining how the transmitted wavefront includes information onthe reflected one.Thanks to finite differences simulations, the experiment has beennumerically modeled. The reconstructed movie of the propaga-tion of the emitted wave fronts inside the plate gives a clear illus-tration of the focusing techniques.


Scaling of Stability Limits by Use of Universal Flame Trans-fer FunctionsMartin Lohrmann, Nikolaos Zarzalis, Horst BüchnerUniversität Karlsruhe, Engler-Bunte-Institut, Bereich Verbren-nungstechnikFor the improvement of the efficiency of gas turbines a furtherincrease of the pressure ratio becomes necessary and therefore,the preheating temperatures of the combustion air are increasing,too. Especially, highly turbulent swirl-stabilized flames, favouredfor gas turbine applications, are often prone to self-sustained, pe-riodic combustion instabilities. This increased tendency to the for-mation of flame/pressure oscillations is primarily caused by highvolumetric reaction densities of premixed swirl flames and - con-sequently - reduced delay times and ”faster” responses of theflame to disturbances of the mixture mass flow rate. Today, the-oretical models for the quantitative prediction of flame dynamicsof turbulent premixed flames in dependence on relevant opera-tion parameters are still missing in literature. In particular, theimpact of the turbulent burning velocity on the axial position ofthe main reaction zone and hence, on the delay time of the flame- required for the fulfilment of Rayleighìs phase criterion - cannot be predicted quantitatively. By theoretical considerations ofthe flame geometry of steady-state turbulent premixed flames aphysical model was derived and validated with measurements offlame transfer functions under well-defined forced, pulsating con-ditions. Now, the model enables to predict the delay times of theflames and consequently, the entire phase angle function j(f) ofthe turbulent swirl flames in dependence on the relevant opera-tion parameters (e.g. equivalence ratio, thermal load, preheatingtemperature or fuel type). Thus, it is now possible to scale and


predict the stability limits for the formation of periodic combus-tion instabilities of lean-premixed combustors with swirl-stabilizedflames.


Thermoacoustic refrigeration : optimisation of the particlevelocity as a function of the acoustic pressurePierrick Lotton, Bertrand Lihoreau, Etienne Gaviot, MichelBruneau, Vitali GusevLAUMClassical thermoacoustic refrigerators mainly consist of a ther-moacoustic core (a stack of plates with heat exchangers at bothends) strategically located in an acoustic standing wave res-onator (half- or quarter-wavelength). In this resonator, the acous-tic pressure p and the particle velocity v are not independent,and their relative phase phi is equal to ± pi/2 (for pure standingwave). Practically, for a given acoustic excitation, the acousticfield (p, v, phi) used for the thermoacoustic process is essentiallygoverned by the geometry of the device and then does not nec-essarily optimises the thermodynamic properties. The aim of thiswork is to study the theoretical behaviour of a thermoacousticdevice in which p, v and phi are considered as independent andadjustable (using adapted shapes for example). The expressionsof the thermoacoustic quantities of interest (namely the tempera-ture difference between the ends of the stack, the thermoacous-tic energy flux and the coefficient of performance) are written anddiscussed in order to reach the optimum of the quantities of in-terest for the application considered. A comparison with the caseof a classical standing wave refrigerator is done. It is shown thatthe standing wave device operates with a velocity which is closedto the theoretical optimal one only for a high drive ratio. At lowerlevel, the parameters which permit an optimisation are discussed.Moreover, it is shown as well that the optimal value of the relativephase between pressure and velocity is never equal to ± pi/2.

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How to reach Strasbourg

by plane: Strasbourg international airport located at Entzheim.Car parks, taxis and bus-shuttle (3 per hour) to the city centre.for information about shuttles (prices, schedule):http://www.strasbourg.aeroport.fr/

by train: Strasbourg, one of the most important railway sta-tions of France, is connected by direct links to numerous citiesof France (Paris, Lyon, Marseille, Nice, Montpellier, Nîmes, Lille ,Bordeaux, Nantes and Toulouse are added in summer).Strasbourg is also situated at the intersection of big internationalaxes and also benefits from quality links with numerous Euro-pean cities (Brussels, Luxemburg, Basel, Bern, Zurich, Stuttgart,Munich, Saarbrücken, Salzburg, Vienna, Milan, Rome, etc).

by road: The French freeway network: to the west and to thenorth, the A4, A34, A31 and A32 freeways permit easy accessof Strasbourg from Paris, Amsterdam, Bruxelles, Luxembourg etBonn via Metz and Sarrebruck. To the south, the axis Strasbourg-Mulhouse, and the A36 intersection of the A6 freeway of Beauneopens routes in direction of Italy and Spain.The German freeway: this European network permits accessto Hamburg, Frankfurt, Basel, Geneva and Milan is less than 15minutes from Strasbourg via Kehl.


Maps of Strasbourg

In Strasbourg, how to reach the "’Palais de la Musique et desCongrès"’?by car from the motorway:• coming from the north: A4 direction Strasbourg – Colmar

exit 1 Wacken (Cronenbourg – place des Halledirection Wacken the Place de Bordeaux – Palais des Congrèsinstitutiones européennes

• coming from the south: A35 direction Strasbourg – Paris –Nancy – Metzexit A350 – Wacken (Roperstau – Avenue des Vosges)direction Wacken then Place de Bordeaux – Palais des Con-grès

FREE large car park at "Palais de la Musique et des Congrès"


by tram (Strassenbahn) or city bus:from city centre or the railway station:Reach "L’Homme de fer"tramway stationTake line B to "Hoenheim Gare"Stop at "Wacken"station.Public transportation tickets can be bought at automatic ma-chines in each tramway station (multilingual machines) andtobacco-, press shops.Prices:• oneway 1.2 EURO• book of tickets: 5 EURO/ 5 tickes• 24 hour tickets – no limitations of journey: 3 EUROEuro).


Maps of congress centre

Ground floor


First floor

Index

Aballea, F.. . . . . . . . . . . . . .241Abrehouch, J. . . . . . . . . . . 294Ache, S.. . . . . . . . . . . . . . . .307Achilles, S. . . . . . . . . . . . . . 385Ackermann, U. . . . . . . . . . 330Ahnert, W. . . . . . . . . . . . . . 270Aichner, R. . . . . . . . . . . . . . 219Ainsworth, W. . . . . . . . . . . 202Alber, T. . . . . . . . . . . . . . . . . . 98Alibert, F. . . . . . . . . . . . . . . .259Allwright, D. . . . . . . . . . . . . 369Alt, N. . . . . . . . . 224, 226, 227Altinsoy, M.E. . . . . . . .80, 142Alziary De Roquefort, T. 371Andrä, H. . . . . . . . . . . . . . . . . 49Anfosso-Ledee, F. . . . . . . 123Angster, J. . . . 340, 341, 344Antes, H. . . . . . . . . . . . . . . . 162Antoni, J. . . . . . . . . . . . . . . .423Arato-Borsi, E. . . . . . . . . . 255Arbey, H.-S. . . . . . . . . . . . . 404Arndt, R. . . . . . . . . . . . . . . . . 54Arnold, K. . . . . 400, 428–430Aschenbrenner, R. . . . . . 212Ashcroft, G. . . . . . . . . . . . . 301Asselineau, M. . . . . . . . . . 384Attenborough, K. . . . . . . . 367Attina, V. . . . . . . . . . . . . . . . 354Attinger, R. . . . . . . . . . . . . . 262Aubry, J.F. . . . . . . . . . . . . . .443Audoin, B. . . . . . . . . . . . . . . . 92Auersch, L. . . . . . . . . . . . . .380Auger, E. . . . . . . . . . . . . . . . 349Auregan, Y. . . . . . . . 147, 304Avan, P. . . . . . . . . . . . . . . . . . 48Averianov, M. . . . . . 154, 368Ayadi, M. . . . . . . . . . . . . . . . . 51

Babazadeh, M. . . . . . . . . . 251Baboux, J.C. . . . . . . . . . . . 157Babuke, G. . . . 58, 272, 417,

418Back, T. . . . . . . . . . . . . . . . . . 72

Bacon, S. . . . . . . . . . . . . . . 205Bader, D. . . . . . . . . . . . . . . . 223Bader, V. . . . . . . . . . . . . . . . 212Badidi Bouda, A. . . 285, 442Bahr, L. . . . . . . . . . . . . . . . . 275Baillet, S.. . . . . . . . . . . . . . .207Bailliet, H. . . . . . . . . . . . . . . 303Bailly, C. . . . . . . . . . . . . . . . 298Balogh, K. . . . 400, 428, 430Baltrusch, M. . . . . . . . . . . . 374Bard, D. . . . . . . . . . . . . . . . . 118Barlet, A. . . . . . . . . . . . . . . .176Baroni, A. . . . . . . . . . . . . . . . 91Barriac, V. . . . . . . . . . . . . . . . 63Barriere, C. . . . . . . . 153, 155Barth, M. . . . . . . 88, 428, 434Barthod, M. . . . . . . . . . . . . 414Bartolomaeus, W. . 111, 137Bartosch, T. . . . . . . . . 52, 225Barzen, S.. . . . . . . . . . . . . .210Basova, M. . . . . . . . . . . . . . 154Bauer, J. . . . . . . . . . . . . .74, 75Bauer, M. . . . . . . . . . . . . . . . .86Baumann, C. . . . . . . . . . . . 186Baumann, I. . . . . . . . . . . . . 415Baumann, U. . . . . . . . . . . . 317Baume, O. . . . . . . . . . . . . . 347Baumgartner, W.-D. . . . . 114Baumhoff, P. . . . . . . . . . . . 204Bay, K. . . . . . . . 264, 330, 403Bayer, R. . . . . . . . . . . . . . . . 264Beaumont, J. . . . . . . . . . . . 188Beautemps, D. . . . . . . . . . 354Becker, H. . . . . . . . . . . . . . .380Becker, K.-F. . . . . . . . . . . . 212Becot, F.-X. . . . . . . . . . . . . 124Bedrici, N.. . . . . . . . . . . . . .239Beerends, J. . . . . . . . . . . . . .62Behler, G. . . . . 132, 159, 350Behr, T. . . . . . . . . . . . . . . . . 130Bel Hadj Salah, H. . . . . . 292Belgroune, D. . . . . . . . . . . 440Bellmann, M. . . . . . . 220, 391

473

Ben Tahar, M. . . . . . . . . . . 292Benammar, A. . . . . . . . . . .286Benchaala, A.285, 286, 442Bendel, K.. . . . . . . . . . . . . .237Benecke, W. . . . . . . . . . . . 215Bentahar, M. . . . . . . . . . . . 157Bento Coelho, J.L.. . . . . .181Benzohra, M.. . . . . .285, 442Berg, A. . . . . . . . . . . . . . . . . 329Bergand, D. . . . . . . . . . . . . 330Berger, P. . . . . . . . . . . . . . . 383Berger, S. . . . . . . . . . . . . . . 281Berger, U. . . . . . . . . . . . . . . 369Bergweiler, S. . . . . . . . . . . . 75Bernard, J. . . . . . . . . . . . . . 275Berraki, M. . . . . . . . . . . . . . . 91Berti, S. . . . . . . . . . . . . . . . . 208Betke, K. . . . . . . . . . . . . . . . 136Beutelmann, R. . . . . . . . . 315Bietz, H. . . . . . . . . . . . . . . . 102Billon, A. . . . . . . . . . . . . . . . 298Birkholz, P. . . . . . . . . . . . . . 424Birnkammer, M. . . . . . . . . 314Birnstingl, S. . . . . . . . . . . . 408Bisping, R. . . . . . . . . . . . . . 106Bjor, O.-H. . . . . . . . . . . 66, 190Blanc-Benon, P. . . . .87, 242,

244, 366–369, 372Blau, M. . . . . . . . . . . . . . . . . . 60Blauert, J. . . . . . . . . . . . . . . 114Blum, A. . . . . . . . . . . . . . . . 335Blumrich, R. . . . . . . .346, 365Boccara, G. . . . . . . . . . . . . 435Bockhorn, H. . . . . . . . . . . . 433Bodden, M. . . . . . . . . . . . . 222Boegli, H. . . . . . . . . . . . . . . 186Bohm, J. . . . . . . . . . . . . . . . 337Bojar, H. . . . . . . . . . . . . . . . 427Bongard, F. . . . . . . . . . . . . . . 57Bonnefoy, X. . . . . . . . . . . . 378Bonnet, J.-C. . . . . . . . . . . . . 52Boone, M. . . . . . . . . .328, 334Boonen, R. . . .127, 150, 151Booz, G. . . . . . . . . . . . . . . . 222Borello, G. . . . . . . . . . . . . . 163Bork, I. . . . . . . .128, 251, 253Bormann, V. . . . . . . . . . . . .392

Borsch-Galetke, E. 426, 427Bosch, A. . . . . . . . . . . . . . . 126Bosse, M. . . . . . . . . . . . . . . 401Botteldooren, D. . . . 184, 347Bou Matar, O. . . . . . . . . . . 289Bouaoua, N. . . . . . . . . . . . 338Boubezari, M. . . . . . . . . . . 181Boucheron, R.. . . . . . . . . .303Bouchet, G. . . . . . . . . . . . . 147Boulanger, P. . . . . . . . . . . . 367Boullet, I. . . . . . . . . . .138, 139Boussard, P. . . . . . . . . . . . 131Boustany, R. . . . . . . . . . . . 423Bouvet, P. . . . . . . . . . . . . . . 432Boze, D.. . . . . . . . . . . . . . . .431Braasch, J. . . . . . . . .114, 341Brand, J. . . . . . . . . . . . . . . . 330Brand, T. . . . . . . . . . . . . . . . 315Brandstätt, P. 264, 329, 330,

403, 418Brauer, M.. . . . . . . . .210, 211Braun, E. . . . . . . . . . . . . . . .227Braun, T. . . . . . . . . . . . . . . . 212Brechbühl, M. . . . . . . . . . . 262Brechlin, E. . . . . . . . . . . . . 165Brecht, D. . . . . . . . . . . . . . . 171Breebaart, J. . . . . . . . . . . . 385Breitsamter, N. . . . . . . . . . 382Breteau, J.-M. . . . . . . . . . . . 93Brick, H. . . . . . . . . . . . . . . . . . 83Briers, R. . . . . . . . . . . . . . . . . 61Brink, M. . . . . . . . . . . 379, 395Brinkmann, H. . . . . . . . . . .426Brocard, J. . . . . . . . . . . . . . 315Brockt, G. . . . . . . . . . . . . . . . 76Broglin, T. . . . . . . . . . . . . . . 428Bruneau, A.-M. . . . . . . . . . 236Bruneau, M. . . . 87, 88, 236,

445Brunet, Y. . . . . . . . . . . . . . . 345Buchner, H. . . . . . . . . . . . . 219Buchta, E.. . . . . . . . . . . . . .240Buck, K. . . . . . . . . . . . . 72, 404Buck, M. . . . . . . . . . . . . . . . 218Bucur, V. . . . . . . . . . . . . . . . 288Bui, T. . . . . . . . . . . . . . . . . . . . 83Bukovnik, M. . . . . . . . . . . . 261

Burchardt, T. . . . . . . 426, 427Burkhardt, M. . . . . . . . . . . 266Burkhart, C. . . . . . . . 296, 297Buschbacher, H.-P. . . . . . 295Buss, S. . . . . . . . . . . .122, 415Busse, G. . . . . . . . . . 287, 291Busson, S. . . . . . . . . . . . . . . 61Bös, J. . . . . . . . . . . . . 167, 216Büchner, H. . . . . . . . 433, 444Béquin, P. . . . . . . . . . . . . . . 233Béra, J.-C.. . . . . . . . . .78, 372Bérengier, M. . .90, 242, 347Bøgholm, N. . . . . . . . . . . . 417

Cacciolati, C. . . . . . . . . . . . 160Callens, D. . . . . . . . . . . . . . 283Calmet, I. . . . . . . . . . . . . . . 242Campagna, H. . . . . . . . . . 404Canevet, G. . . . . . . . . . . . . 139Canévet, G. . . . . . . . . . . . . 389Cassereau, D. . . 2, 438, 443Castagnède, B. . . . 156, 290,

441Castellengo, M. . . . . . . . . 187Castor, F.. . . . . . . . . . . . . . .121Cataldi-Spinola, E. 425, 426Cathala, T. . . . . . . . . . . . . . 391Catheline, S. . . . . . . 153, 349Cathiard, M.-A. . . . . . . . . . 354Caulkins, T. . . . . . . . . . . . . 358Cerqueira Revoredo, T. . 416Chapelon, J.Y. . . . . 281, 436Chen, S. . . . . . . . . . . . . . . . 436Chigarev, N. . . . . . . . . . . . . . 93Chilla, E. . . . . . . . . . . . . . . . 337Chudalla, M. . . . . . . . . . . . 326Clairet, J.-M. . . . . . . . . . . . 124Clasen, D. . . . . . . . . . . . . . .162Cleveland, R. . . . . . 282, 368Clorennec, D. . . . . . . . . . . . .90Comte, P. . . . . . . . . . . . . . . 147Conoir, J.-M. . . . . . . . . . . . 232Corteel, E. . . . . . . . . . . . . . 358Coste, O. . . . . . . . . . . . . . . .259Coulouvrat, F. . . . . . 364, 365Cremezi-Charlet, C. . . . 396,

397

Crouzet, F. . . . . . . . . . . . . . 345Crouzet, O.. . . . . . . . . . . . .202Curdes, Y. . . . . . . . . . . . . . .280

D’Alessandro, C. . . 343, 352Dallois, L. . . . . . . . . . 368, 369Dalmont, J.-P. . . . . . . . . . . . 81Dancer, A. . . . . . . . . . .72, 371Daniel, D. . . . . . . . . . 428, 429Daniel, J. . . . . . . . . . . . . . . .116Daniel, P.. . . . . . . . . .309, 375Darinskii, A. . . . . . . . . . . . . 336Dau, T. . . . . . . . . . . . . 200, 206Daub, M. . . . . . . . . . . . . . . . . 80Dauchez, N. . . . . . . . . 76, 234Dazel, O. . . . . . . . . . . . . . . . 274De Bruijn, W. . . . . . . . . . . . 334De Coensel, B. . . . . . . . . . 184De Cássia Cordeiro

Nogueira, R.416

De Greve, B. . . . . . . . . . . . 347De Muer, T. . . . . . . . 184, 347De Roeck, W. . . . . . . . . . . 305De Rosny, J. . . . . . . . .58, 234Debever, C. . . . . . . . . . . . . 234Declercq, N. . . . . . . . . . . . . . 61Decultot, D. . . . . . . . . . . . . 294Defrance, J. . . . . . . . 241, 244Defreville, B. . . . . . . . . . . . 178Degen, ?. . . . . . . . . . . . . . . 260Degrieck, J. . . . . . . . . . . . . . 61Dehé, A. . . . . . . . . . . 210–212Dekeyrel, Y. . . . . . . . . . . . . 134Delb, V. . . . . . . . . . . . . . . . . 266Delerue, O.. . . . . . . . . . . . .112Demany, L. . . . . . . . .208, 210Demirdjian, F. . . . . . . . . . . 389Depollier, C. . . 92, 275, 281,

436Deraes, L. . . . . . . . . . . . . . .248Derleth, P. . . . . . . . . . . . . . .423Deschamps, M. . . . . . . . . 290Desmet, W. . . 151, 165, 305Despaux, G. . . . . . . . . . . . 286Deutsch, W. . . . . . . . . . . . . 222Devaux, C. . . . . . . . . 234, 430

Deville, L. . . . . . . . . . . . . . . 157Diegmann, V.. . . . . . . . . . .362Ding, H. . . . . . . . . . . . . . . . . 356Diniz Guimarães, J.H. . . 254Djelouah, H.. . . . . . . . . . . .440Dogui, A. . . . . . . . . . . . . . . . 292Donzier, A. . . . . . . . . . . . . . 145Dos Santos, S. . . . . 155, 289Drai, R. . . . . . . . . . . . . . . . . 286Drechsler, A. . . . . . . . . . . . 191Dreyer, D. . . . . . . . . . . . . . . 163Dreyer, T. . . . . . . . . . . . . . . 282Driessen, N.. . . . . . . . . . . .352Drotleff, H.. . .135, 273, 409,

410Dual, J. . . . . . . . . . . . . . . . . 426Dubois, D. . . . . . . . . . . . . . .179Dubus, B. . . . . . 91, 230, 250Duclos, A. . . . . . . . . . . . . . . 239Ducorps, A. . . . . . . . . . . . . 207Durocher, J.-N. . . . . . . . . . 236Dutilleux, G. . . . . . . .266, 319

Eckoldt, D. . . . . . . . . 403, 418Ecotiere, D. . . . . . . . 266, 345Ederer, H.-J. . . . . . . . . . . . 175Ehrlich, J. . . . . . . . . . . . . . . 172Eichelhard, O. . . . . . . . . . . . 51Elaqra, H. . . . . . . . . . . . . . . 293Elguerjouma, R. . . . 157, 293Ellermeier, W. 206, 318, 421Elmaimouni, L. . . . . . . . . . 440Elsaghir, E.. . . . . . . . . . . . .405Enzner, G. . . . . . . . . . . . . . 217Evert, F. . . . . . . . . . . . . . . . . 148Ewert, S. . . . . . . . . . . 200, 206

Fabre, J.-J. . . . . . . . . . . . . . 283Faiz, B.. . . . . . . . . . . . . . . . .294Falourd, X. . . . . . . . . . . . . . 173Fankhauser, C. . . . . . . . . . 225Fasolo, C. . . . . . . . . . . . . . . 286Fastl, H..115, 307, 318, 357Faucon, G. . . . . . . . . 199, 203Faure, J. . . . . . . . . . . . . . . . 389Favre, B. . . . . . . . . . . . . . . . 128Fedtke, T. . . . . . . . . . 272, 338

Fein, O. . . . . . . . . . . . . . . . . 152Feiss, C. . . . . . . . . . . . . . . . 264Fellah, M. . . . . . . . . . . . . . . 436Fellah, Z.E.A. . . . . . 281, 436Fellner, M.. . . . . . . . . . . . . .408Fels, J. . . . . . . . . . . . . . . . . . 281Ferekidis, C. . . . . . . . . . . . . . 96Feuillard, G. . . . . . . . . . . . . 339Fiebig, A. . . . . . . . . . . . . . . 179Filippi, P. . . . . . . . . . . . . . . . 237Fink, M. . . . . . . . . . . . . . . . . .47,

58, 153, 155, 231,288, 349, 435, 443

Finsterhölzl, H. . . . . . . . . . 314Fischer, E. . . . . . . . . . . . . . 203Fischer, F. . . . . . . . . .186, 266Fischer, G. . . . . . . . . . . . . . 330Fischer, H.-M. 98, 101, 191,

195Fischer, Martin, 305Fischer, Matthias, 161Fischer, S. . . . . . . . . . . . . . 405Fleischer, G. . . . . . . 277, 278Fleischer, H. . . . . . . . . . . . 374Flemming, F. . . . . . . . . . . . . 82Fleury, V. . . . . . . . . . . . . . . . 298Fließer, W.. . . . . . . . . . . . . . .54Flötke, H. . . . . . . . . . . . . . . . .51Fodiman, P. . . . . . . . . . . . . 258Foggia, T. . . . . . . . . . . . . . . . 78Fortineau, J. . . . . . . . . . . . 289Foy, F. . . . . . . . . . . . . . . . . . .256Franck, A. . . . . . . . . . . . . . . . 95Franklin, H.. . . . . . . . . . . . .232Freese, N. . . . . . . . . . . . . . .415Friot, E. . . . . . . . . . . . . 68, 309Fritz, C.. . . . . . . . . . . . . . . . . .77Frohly, J. . . . . . . . . . . 248, 443Fruhmann, M. . . . . . 307, 310Fuchs, H. 56, 135, 272, 409,

410Fueldner, M. . . . . . . . . . . . 210Furjes, A.T. . . . . . . . . . . . . .255Förster, L. . . . . . . . . . . . . . . 437Füldner, M. . . . . . . . .211, 212Füllgrabe, C. . . . . . . . . . . . 200Fürst, P. . . . . . . . . . . . . . . . . 136

Gabi, M. . . . . . . . . . . . . . . . . . 85Garwon, M. . . . . . . . . . . . . 149Gatignol, P. . . . . . . . . . 89, 239Gauduin, B. . . . . . . . . . . . . 131Gaul, L. . . . . . . 152, 161, 169Gautier, F. . . . . . . . . . . 76, 419Gautier, P.-E. . . . . . . . . . . . 256Gauvreau, B. .242, 345, 347Gaviot, E. . . . . . . . . . . . . . . 445Gazengel, B. . . . . . . 117, 235Gegenmantel, E. . . . . . . . 219Geiger, W. . . . . . . . . . . . . . 269Geisler, R. . . . . . . . . 246, 247Gennisson, J.-L. . . . . . . . .153Genuit, K. . . . . . 55, 184, 228Gerlach, A. . . . . . . . . . . . . .237Gerretsen, E.. . . . . . . . . . .102Gervais, Y. . . . . . . . . . . . . . 297Gessner, R. . . . . . . . . . . . . 263Gibbs, B. . . . . . . . . . . . 98, 101Gibiat, V. . . . . . . . . . . . . . . . 180Gierlich, H.W. . . 64, 65, 220,

414Gilbert, J. . . . . . 81, 373, 419Gilroy, L. . . . . . . . . . . . . . . . 173Ginn, B. . . . . . . . . . . . . . . . . 417Glettler, A. . . . . . . . . . . . . . 225Glocker, C. . . . . . . . . . . . . . 425Goertz, A. . . . . . . . . . . . . . .270Goossens, S. . . . . . 129, 253Gorelik, V. . . . . . . . . . . . . . .348Gougeon, S. . . . . . . . . . . . . .93Gounon, P. . . . . . . . . . . . . . 144Gourévitch, B. . . . . . . . . . .199Goydke, H. . . . . . . . . . . . . . . 97Gozard, P. . . . . . . . . . . . . . .391Graf, F. . . . . . . . . . . . . 284, 408Graf, J. . . . . . . . . . . . . . . . . . . 95Granger, C. . . . . . . . 230, 250Gretzki, R. . . . . . . . . . . . . . 399Greverie, L. . . . . . . . . . . . . 128Griefahn, B. . . 105, 109–111Griffiths, J. . . . . . . . . . . . . . 271Griffiths, S. . . . . . . . . . . . . . 235Grimault, A. . . . . . . . . . . . . 290Grimault, N. . . . . . . . . . . . . 201Gros, L. . . . . . . . . . . . . . . . . 358

Grulier, V. . . . . . . . . . . . . . . 273Gryba, T. . . . . . . . . . . . . . . . 440Guastavino, C. . . . . . . . . . 187Guerinot, J.-M. . . . . . . . . . 227Guianvarc’H, C. . . . . . . . . 236Guidati, S. . . . . . . . . . .55, 119Guignard, T. . . . . . . . . . . . .418Guillemain, P. . . . . . . . . . . . .81Gusev, V. . . .87, 88, 93, 156,

158, 441, 445Guski, R. . . . . . . . . . . . . . . . 395Guy, P. . . . . . . . . . . . . . . . . . 293Guyader, J.-L. . . . . . 160, 167Guérin, A. . . . . . . . . . . . . . . 203Gärtner, C. . . . . . . . . 182, 183Götsch, M. . . . . . . . . 425, 426

Habault, D. . . . . . . . . 237, 389Haberkern, R. . . . . . 197, 433Haberkorn, M. . . . . . . . . . .147Habisreuther, P. . . . . . . . . 433Halimi, R. . . . . . . . . . 285, 442Hallam, J. . . . . . . . . . . . . . . 338Hallmann, S. . . . . . . . . . . . 415Hamacher, V.. . . . . . . . . . .203Hamery, P. . . . . 72, 146, 349Hammer, F.. . . . . . . . . . . . .144Hampel, S. . . . . . . . . . . . . . 162Hamzaoui, N. 140, 221, 311Hanisch, R. . . . . . . . . . . . . 329Hansen, H. . . . . . . . . . . . . .310Haslev, H. . . . . . . . . . . . . . . 255Hauenstein, J. . . . . . . . . . .266Hauer, I. . . . . . . . . . . . . . . . . . 52Haulick, T. . . . . . . . . . . . . . .218Haumesser, L. . . . . . . . . . 289Haverkamp, M. . . . . 121, 185Haw, G. . . . . . . . . . . . . . . . . 230Hayne, B. . . . . . . . . . . . . . . 402Hazmoune, M.. . . . . . . . . . .93Heck, P. . . . . . . . . . . . . . . . . 353Hehner, C. . . . . . . . . . . . . . 181Heimann, D.. . . . . . .346, 365Heimann, R. . . . . . . . . . . . 337Heinrichs, R. . . . . . . . . . . . 222Heiß, A. . . . . . . . . . . . . 94, 320Hellbrück, J. . . . . . . .107, 313

Helleman, H. . . . . . . . . . . . 328Helmstetter, A. . . . . . . . . . 293Hemmert, W. . . . . . . . . . . . 316Hemsing, J. . . . . . . . . . . . . 403Hengst, M. . . . . . . . . . . . . . 337Hengy, S. . . . . . . . . . . . . . . 144Henning, B. . . . . . . . . . . . . 340Henning, P. . . . . . . . . . . . . .417Hennings, D. . . . . . . . . . . . 406Herbertz, J. . . . . . . . . . . . . 284Herhold, J. . . . . . . . . . . . . . 177Hertwig, R. . . . . . . . . . . . . . 325Herzog, P. 72, 233, 387, 420Hessinger, J. . . . . . . . . . . . 295Hettler, S. . . . . . . . . . . . . . . 189Heuer, S. . . . . . . . . . . . . . . .224Heutschi, K. . . . . . . . . . . . . 264Heß, W. . . . . . . . . . . . . . . . . 422Hibral, M. . . . . . . . . . . . . . . 197Hildebrand, H.. . . . . . . . . .283Hilge, C. . . . . . . . . . . . . . . . 412Hintzsche, M. . . . . . . . . . . 324Hirsch, K.-W. .241, 243, 323Hirschberg, A. . . . . . . . . . .352Hladky, A.-C. . . . . . . . . . . . 230Hoffmann, R. . . . . . . . . . . .355Hojan, E. . . . . . . . . . . . . . . . 318Hojan-Jezierska, D. . . . . 318Holmberg, M. . . . . . . . . . . 316Holstein, P. . . . 88, 116, 223,

405, 434Holtz, F. . . . . . . . . . . . . . . . . 295Hoppe, C. . . . . . . . . . . . . . . 410Hotz, E. . . . . . . . . . . . . . . . . 411Huber, R. . . . . . . . . . . . . . . 143Hudde, H. . . . . 279, 280, 317Huebelt, J. . . . . . . . . . . . . . 306Hübelt, J. . . . . . . . . . . . . . . .405Hübner, G. . . . . . . . . . 68, 320Héron, N. . . . . . . . . . . . . . . 370

Ickler, A. . . . . . . . . . . . . . . . 147Illaire, H. . . . . . . . . . . . . . . . 151Ing, R.K. . . . . . . . . . . . . . . . 349Irmer, V. . . . . . . . . . . . . . . . .360Isabey, B.. . . . . . . . . . . . . . . .57Izbicki, J.-L. . . . . . . . . . . . . . 92

Jablonski, M. . . . . . . . . . . . 188Jackèl, D. . . . . . . . . . . . . . . 424Jacob, X. . . . . . . . . . . . . . . . 153Jaillet, F. . . . . . . . . . . . . . . . 277Jakob, A. . . . . . . . . . . . . . . . . 67Jaksch, M. . . . . . . . . . . . . . 261Jalics, K. . . . . . . . . . . . . . . . . 52Janicka, J. . . . . . . . . . . . . . . . 82Jaouen, L. . . . . . . . . . . . . . 239Jekosch, U. . .137, 139, 142,

355Jennewein, D. . . . . . . . . . . . 51Johan, Z. . . . . . . . . . . . . . . .370John, W. . . . . . . . . . . . . . . . 400Johnsrude, I. . . . . . . . . . . . 351Jokisch, O. . . . . . . . . . . . . . 356Joly, N. . . . . . . . . . . . . . . . . .430Joly, V. . . . . . . . . . . . . . . . . . 233Jordan, P. . . . . . . . . . . . . . . 297Joseph, P. . . . . . . . . . . . . . . . 71Jund, S. . . . . . . . . . . . . . . . . 432Junge, S. . . . . . . . . . . . . . . .215Junker, F. . . . . . . . . . 345, 347Jäger, B. . . . . . . . . . . . . . . . 270Jüschke, M. . . . . . . . . . . . . . 86

Kaernbach, C.. . . . . . . . . .209Kalivoda, M.. . . . . . . . . . . .261Kaltenbacher, B. . . . . . . . 275Kaltenbacher, M. . . . . . . . 275Kandelaki, D. . . . . . . . . . . .320Kanj, B. . . . . . . . . . . . . . . . . 232Kaouri, K. . . . . . . . . . . . . . . 369Kappel, R. . . . . . . . . . . . . . 153Kastka, J. . . . . . . . . . . . . . . 327Katz, B. . . . . . . . . . . . 335, 343Katzer, R. . . . . . . . . . . . . . . 354Kefting, D. . . . . . . . . . . . . . .246Kellermann, W. . . . . . . . . . 219Kellert, T. . . . . . . . . . . . . . . . . 50Kerber, S. . . . . . . . . . . . . . . 357Kergomard, J. . . . . . . . . . . . 81Kern, A. . . . . . . . . . . . . . . . . 250Kettler, F. . . . . . . . 64, 65, 220Khelil, M. . . . . . . . . . . . . . . . 286Khelladi, H. . . . . . . . . . . . . 440Khokhlova, V. . . . . . 154, 368

King, R. . . . . . . . . . . . . . . . . 149Klann, M. . . . . . . . . . . . . . . 350Klatte, M. . . . . . . . . . . . . . . 108Kleb, U. . . . . . . . . . . . . . . . . 284Kleiner, M. . . . . . . . . . . . . . 311Klemenz, H. . . . . . . . . . . . .279Klemenz, M. . . . . . . 307, 308Kling, C.. . . . . . . . . . . . . . . .100Klippel, W. . . . . . . . . . . . . . 252Knöfel, B. . . . . . . . . . . . . . . . .53Kob, M. . . . . . . . . . . . 353, 354Koch, B. . . . . . . . . . . . . . . . .265Koch, C. . . . . . 174, 336, 350Koch, J.-R. . . . . . . . . . . . . . 140Koch, M. . . . . . . . . . . . . . . . 212Koch, P. . . . . . . . . . . . . . . . . 249Koehl, V. . . . . . . . . . . . . . . . 388Koh, H.-I. . . . . . . . . . . . . . . . . 70Kohler, K. . . . . . . . . . . . . . . 195Kohlrausch, A. . . . . 332, 385,

420Kollmeier, B. . . . . . . 143, 315Koop, L. . . . . . . . . . . . . . . . . 302Koopmann, N. . . . . . . . . . .121Kopco, N. . . . . . . . . . . . . . . 113Kotterba, B. . . . . . . . . . .74, 75Kovalev, A. . . . . . . . . . . . . . 158Kraft, J. . . . . . . . . . . . . . . . . 268Krahé, D. . . . . . . . . . . . . . . . . 69Kraus, M. . . . . . . . . . . . . . . . .68Krebber, J. . . . . . . . . . . . . . 355Krefting, D. . . . . . . . . 249, 251Kristen, M. . . . . . . . . . . . . . 250Kristiansen, U. . . . . . . . . . 166Kroman, L. . . . . . . . . . . . . . 324Kropp, W. . . . . 123, 125, 151Krump, G. . . . . . . . . . . . . . . 387Kruse, R. . . . . . . . . . . . . . . .415Krämer, M. . . . . . . . . . . . . . 403Kröninger, D. . . . . . . . . . . . 247Krüger, F. . . . . . . . . . . . . . . 380Krüger, H. . . . . . . . . . . . . . . 214Krüger, J. . . . . . . . . . . . . . . 121Kubaczyk, C. . . . . . . . . . . . 172Kubicek, R.. . . . . . . . . . . . .437Kubo, N. . . . . . . . . . . . . . . . 415Kuhnt, S. . . . . . . . . . . . . . . . 109

Kulka, M. . . . . . . . . . . . . . . .106Kunze, R. . . . . . . . . . . . . . . 337Kurtze, L. . . . . . . . . . . .72, 216Kurz, R. . . . . . . . . . . . . . . . . 296Kurz, T. . . . . . . . . . . . 245–247Kurze, U. . . . . . . . . . . 332, 344Kuwano, S. . . . . . . . . . . . . .310Köhler, H. . . . . . . . . . . . . . . 284Költzsch, P. . . . . . . . . .83, 392König, C. . . . . . . . . . . . . . . . 415König, F.M. . . . . . . . . . . . . . 399Künzel, K. . . . . . . . . . . . . . . 175

Laback, B. . . . . . . . . . . . . . 114Labouret, S. . .246, 248, 443Lacroix, A. . . . . . . . . . . . . . 425Ladegaard, P. . . . . . . . . . . 255Lafarge, D. . . . . . . . . . . . . . 239Laguerre, L. . . . . . . . . . . . . 290Lamarque, C.-H. . . . . . . . 274Lambert, J. . . . . . . . . . . . . .359Lang, J. . . . . . . . . . . . . . . . . 191Lang, W. . . . . . . . . . . . . . . . 215Lange, B. . . . . . . . . . . . . . . 224Langer, S. . . . . . . . . . . . . . . 162Langner, G. . . . . . . . . . . . . 204Laniray, M. . . . . . . . . . . . . . 178Larsen, H.. . . . . . . . . . . . . .324Lasaygues, P. . . . . . 438, 439Laur, R. . . . . . . . . . . . . . . . . 211Lauriks, W. . . . . . . . . 281, 436Lauterborn, W. . . . 245–247,

249, 251Lauzin, F. . . . . . . . . . . . . . . 347Lavandier, C. . . . . . . 178, 397Lavandier, M.. . . . . . . . . . .387Lazarus, H. . . . . . . . . . . . . 106Le Bot, A. . . . . . . . . . . . . . . 168Le Bouquin Jeannès, R.199,

203Le Pollès, T. . . . . . . . . . . . . . 90Le Roux, J.-C. . . . . . . . . . .273Le Saout, J.-Y. . . . . . . . . . . .64Lebedev, A. . . . . . . . . . . . . 371Lebiedowska, B. . . . . . . . 188Lecheler, A. . . . . . . . . . . . . 418Leckschat, D.. . . . . . . . . . .118

Leduc, D. . . . . . . . . . . . . . . . . 92Lefebvre, A. . . . . . . . . . . . . 283Lefebvre, J.-E.. . . . . . . . . .440Lefebvre, J.-P. . . . . . . . . . . 439Legros, C. . . . . . . . . . . . . . . 411Leistner, M.. .135, 273, 406,

410Leistner, P. . . . .71, 104, 189,

196, 329Lemaitre, G. . . . . . . . . . . . .312Lemarrec, L. . . . . . . . . . . . 439Lentz, T. . . . . . . .59, 350, 353Lenz, U. . . . . . . . . . . . . . . . .383Lenzer, M. . . . . . . . . . . . . . 410Lepoint, T.. . . . . . . . .246, 248Lerch, R. . . . . .250, 275, 338Leroux, M. . . . . . . . . . . . . . 304Leroy, O. . . . . . . . . . . . . . . . . 61Leroy, P. . . . . . . . . . . . . . . . . . 57Lethiecq, M. . . . . . . .232, 339Letourneaux, F. . . . . . . . . 259Leue, E. . . . . . . . . . . . . . . . .109Lieb, M. . . . . . . . . . . . . . . . . 217Liebler, M. . . . . . . . . . . . . . .282Liegl, R. . . . . . . . . . . . . . . . . 381Liengme, J.-D.. . . . . . . . . .186Lievens, M.. . . . . . . . . . . . .354Lihoreau, B. . . . . . . . 242, 445Lissek, H.. . . . . . . . . . . .73, 74Litjens, S. . . . . . . . . . . . . . . 190Loewer, V. . . . . . . . . . . . . . .268Lohrmann, M. . . . . . . . . . . 444Loisy, P. . . . . . . . . . . . . . . . . 221Lopez, I. . . . . . . . . . . 141, 352Lorang, X. . . . . . . . . . . . . . .256Lorenz, K. . . . . . . . . . . . . . . 134Lorenzi, C. . . . . . . . . 200, 210Loro, C. . . . . . . . . . . . . . . . . 407Lotton, P. . . . . . . . 87, 88, 445Louni, R. . . . . . . . . . . . . . . . 441Loyau, V. . . . . . . . . . . . . . . . 339Luedecke, O. . . . . . . . . . . . 118

Maack, J. . . . . . . . . . . . . . . 194Macedo, M.R.V. . . . . . . . . 416Mackenzie, D. . . . . . . . . . . . 88Maess, M.. . . . . . . . . . . . . .169

Maffiolo, V. . . . . . . . . . . . . . 187Magagnato, F. . . . . . . . . . . . 85Magand, F. . . . . . . . . . . . . . 145Maillard, J. . . . . . . . . . . . . . 359Majdak, P. . . . . . . . . . . . . . . 114Makarski, M. . . . . . . . . . . . 159Mammen, H.-T.. . . . . . . . .400Manfredi, M.-J. . . . . . . . . . 370Manvell, D. . . . . . . . . 324, 361Marchiano, R. . . . . . . . . . . 365Markiewicz, M. . . . . . 49, 169Marks, A. . . . . . . . . . . . . . . 110Marohn, H.-D. . . . . . . . . . . 321Marquis-Favre, C. . 186, 389Martin, H. . . . . . . . . . . . . . . 102Martin, J. . . . . . . . . . . . . . . .359Martin, V.. . . . . . . . . . . . . . .418Martinez, D.S. . . . . . . . . . . 326Martner, O. . . . . . . . . . . . . .314Marx, H. . . . . . . . . . . . . . . . 223Maschke, C.. . . . . . .378, 396Masti, R. . . . . . . . . . . . . . . . 165Mathieu, J. . . . . . . . . . . . . . 286Matsui, T. . . . . . . . . . . . . . . 310Mattei, P.-O. . . . . . . . 164, 166Matuschek, R.. . . . . . . . . .136Maue, J. . . . . . . . . . . . . . . . 325Mauler, D. . . . . . . . . . . . . . . 217Maunder, R. . . . . . . . . . . . . . 51Maurel, Y. . . . . . . . . . . . . . . 372Maurin, M. . . . . . . . . 188, 364Maxit, L. . . . . . . . . . . . . . . . 160May, R. . . . . . . . . . . . . . . . . . . 49Mayer, A.. . . . . . . . . . . . . . .158Maysenhölder, W. . . . . . . 329Maze, G. . . . . . . . . . . . . . . . 294Mcadams, S. . . . . . . 139, 312Mcculloch, C.F. . . . . . . . . . 159Mebtouche, A. . . . . . . . . . 442Mechel, F. . . . . . . . . . . . . . . 331Mehnert, D. . . . . . . . . . . . . 355Mehra, S.-R. . . . . . . 190, 198Meier, H.-E. . . . . . . . . . . . . . 47Meinke, M. . . . . . . . . . . . . . . 83Meis, M.. . . . . . . . . . . . . . . .108Meister, A. . . . . . . . . 412, 413Melichar, M. . . . . . . . . . . . . 355

Mellert, V. . . . 240, 338, 391,415

Meloni, T. . . . . . . . . . . . . . . 266Mercier, S. . . . . . . . . . . . . . 384Meri, H. . . . . . . . . . . . . . . . . . 92Meschke, J. . . . . . . . . . . . . 415Metkemeijer, R. . . . . . . . . 134Metten, B. . . . . . . . . .245, 247Mettin, R. . . . . 246, 249, 251Metzen, H. . . . . . . . . 196, 325Meunier, S. . . 139, 309, 372,

387, 389Meyer, T. . . . . . . . . . . . . . . . 401Meynial, X. . . . . . . . . . . . . . . 73Miehling, H. . . . . . . . . . . . . 148Miklós, A. . . . . 340, 341, 344Millard, C. . . . . . . . . . . . . . . 404Minonzio, J.-G. . . . . . . . . . 288Mitri, F.G. . . . . . . . . . . . . . . 436Miège, B.. . . . . . . . . . . . . . .362Moehler, U. . . . . . . . 344, 394Moeller, S. . . . . . . . . . . . . . 355Mohler, P. . . . . . . . . . . . . . . 402Mohr, J. . . . . . . . . . . . . . . . . 408Moldenhauer, J. . . . . . . . . 435Moldrzyk, C.. . . . . . . . . . . .131Molliex, F. . . . . . . . . . . . . . . 145Monnier, T. . . . . . . . . . . . . . 157Montaldo, G. . . . . . . 155, 231Montresor, S. . . . . . . . . . . .275Mooshammer, C. . . . . . . . 424Moravec, O. . . . . . . . . . . . . 419Moreau, Stéphane, 300Moreau, Sébastien, 116Moroni, C. . . . . . . . . . . . . . .210Mors, A. . . . . . . . . . . . . 53, 222Morvan, B. . . . . . . . . . . . . . . 92Moudden, A. . . . . . . . . . . . 294Mounier, D. . . . . . . . . . . . . . . 93Moussatov, A.250, 290, 441Mueller, R. . . . . . . . . 277, 278Mullie, F. . . . . . . . . . . . . . . . 246Musa Shufani, S. . . . . . . . 413Muth, T. . . . . . . . . . . . . . . . . 426Muzet, A. . . . . . . . . . . . . . . 377Myck, T. . . . . . . . . . . . . . . . . 321Möck, T. . . . . . . . . . . . . . . . .103

Möhler, U. . . . . . . . . . . . . . . 381Möller, S. . . . . . . . . . . . 66, 139Möser, M. . . . . . 70, 149, 274Müller, Alexander, 121Müller, Andreas, 225Müller, B. . . . . . . . . . . . . . . .258Müller, C.. . . . . . . . . . . . . . .330Müller, Reinhard, 437Müller, Roland, 88, 116Müller, Rolf, 338Müller-Boruttau, F.. . . . . .382Mérida, E. . . . . . . . . . . . . . .176

Namba, S. . . . . . . . . . . . . . 310Nassar, G. . . . . . . . . . . . . . 294Nasshan, K. . . . . . . . . . . . .254Naz, P. . 144, 146, 349, 371,

391, 428Nazarov, V. . . . . . . . . . . . . .156Nechad, N. . . . . . . . . . . . . .293Neise, W. . . . . . . . . . 149, 301Nejedl, V. . . . . . . . . . . . . . . 172Nettelbeck, C. . . . . . 119, 229Neuhaus, L. . . . . . . . . . . . . 301Neuschaefer-Rube, C. . 353,

354Nguyen, Q.S.. . . . . . . . . . .256Nicklich, H. . . . . . . . . . . . . . 216Nicol, R. . . . . . . . . . . . .61, 358Niederdränk, T. . . . .214, 279Nikolic, I. . . . . . . . . . . . . . . . 190Nini, G. . . . . . . . . . . . . . . . . 404Nocke, C. . . . . . . . . . . . . 2, 412Nongaillard, B. . . . . . . . . . 294Nordborg, A. . . . . . . . . . . . . 54Nordmann, R. . . . . . . . . . . . 72Norris, D. . . . . . . . . . . . . . . .351Notbohm, G. . . . . . . 182, 183Novo, P. . . . . . . . . . . . . . . . . 256Noël, Y. . . . . . . . . . . . . . . . . 294

Oberfeld, D. . . . . . . . . . . . . 393Ochmann, M.. . . . . . .83, 161Ochse, M. . . . . . . . . . . . . . . 204Oertli, J. . . . . . . . . . . . . . . . .265Ohanessian, H. . . . . . . 79, 80Ollivier, S. . . . . . . . . . 366, 367

Olsen, E. . . . . . . . . . . . . . . . 324Olszewski, D.. . . . . . . . . . .340Onnich, J. . . . . . . . . . 265, 344Osetrov, A. . . . . . . . . . . . . . 161Otcenasek, Z. . . . . . . . . . . 422Oudina, A. . . . . . . . . . . . . . 440Ouisse, M. . . . . . . . . 160, 167Oxenham, A. . . . . . . . . . . . 206Ozawa, K. . . . . . . . . . . . . . .333

Padilla, A. . . . . . . . . . . . . . . 180Pagneux, V. . 147, 235, 238,

239, 304Palacio, D. . . . . . . . . . . . . . 231Pantle, I. . . . . . . . . . . . . . . . . 85Panzer, J. . . . . . . . . . . . . . . . 96Pape, D.. . . . . . . . . . . . . . . .424Paquier, M. . . . . . . . . . . . . . . 78Pareige, P. . . . . . . . . . . . . . . .92Parizet, E. . . . 140, 221, 311,

315, 388Parot, J.-M. . . . . . . . . . . . . 434Pascal, J.-C.. . .76, 273, 430Pastillé, H. . . . . . . . . . . . . . 228Patsouras, C.122, 126, 314,

411Patsouras, D. 122, 126, 314,

411Patterson, R. . . . . . . . . . . . 351Paulsen, R. . . . . . . . . . . . . 176Pavic, G. . . . . . . . . . . . . . . . 437Pedersen, B. . . . . . . . . . . . 421Peeters, H. . . . . . . . . . . . . . 141Pegam, R. . . . . . . . . . . . . . 355Peine, H. . . . . . . . . . . . . . . . 171Peissig, J. . . . . . . . . . . . . . . 348Pellegrini, R. . . . . . . . . . . . 359Pellicier, A. . . . . . . . . . . . . . 193Pelorson, X. . . . . . . . . . . . . 352Penelet, G. . . . . . . . . . . . . . . 88Peremans, H. . . . . . . . . . . 338Perret-Liaudet, J. . . . . . . . 168Perrigot, J. . . . . . . . . . . .79, 80Peters, M. . . . . . . . . . . . . . . 322Petersen, S. . . . . . . . . . . . . 163Petersson, B.. . . . . .125, 126Petiot, J.-F. . . . . . . . . . . . . . 373

Petsch, O. . . . . . . . . . . . . . .433Peyre, L. . . . . . . . . . . . . . . . 283Pfaffelhuber, K. . . . 122, 126,

314, 411Pfleiderer, K. . . . . . . 287, 291Pfäfflin, F. . . . . . . . . . . . . . . 362Pham, M.C. . . . . . . . . . . . . 232Picart, P. . . . . . . . . . . . . . . . . 93Picaut, J. . . . . . . . . . . . 90, 129Pichler, D. . . . . . . . . . . . . . . 383Pico Vila, R. . . . . . . . . . . . .419Pin, J.C. . . . . . . . . . . . . . . . .414Pinte, G. . . . . . . . . . . . . . . . 151Pirot, B. . . . . . . . . . . . . . . . . 232Piscoya, R. . . . . . . . . . . . . . . 83Piserchia, P.-F. . . . . . . . . . 369Pitsch, S. . . . . . . . . . 340, 341Pittelkau, A. . . . . . . . . . . . . 400Plank, T. . . . . . . . . . . . . . . . 206Pluymers, B. . . . . . . . . . . . 165Plüss, P.. . . . . . . . . . . . . . . .402Poignand, G. . . . . . . . . . . . . 87Poirson, E. . . . . . . . . . . . . . 373Poisson, F. . . . . . . . . 257, 259Polack, J.-D. . . . . . . . . 57, 187Potel, C. . . . . . . . . . . . . . . . . . 92Prada, C.. . . . . . . . . . . . . . .288Prager, J. . . . . . . . . . 125, 126Premat, E. . . . . . . . . 244, 362Pressnitzer, D. . . . . . . . . . 207Priebsch, H.H. . . . . . . . . . . .52Priour, M. . . . . . . . . . . . . . . 244Prisack, H.-B. . . . . . . . . . . 427Probst, W.. . . . . . . . .276, 363Puder, H.. . . . . . . . . . . . . . .203Putz, K. . . . . . . . . . . . . . . . . 284Pötter, M. . . . . . . . . . . . . . . 319Pétrier, C. . . . . . . . . . . . . . . 246Pézeril, T. . . . . . . . . . . . . . . . 93

Qin, Q. . . . . . . . . . . . . . . . . . 367Quieffin, N. . . . . . . . . . . . . .349

Raabe, A.88, 400, 428–430,434

Raake, A. . . . . . 63, 139, 142Rabau, G. . . . .309, 372, 420

Rabold, A. . . . . . . . . . . . . . 295Radziszewski, E. . . . . . . . 283Ragot, R. . . . . . . . . . . . . . . 207Raimbault, M. . . . . . 396, 397Rajman, M. . . . . . . . . . . . . 355Rambausek, N. . . . 264, 329,

403Ramos, C. . . . . . . . . . . . . . 208Ranostaj, F. . . . . . . . . . . . . 425Rau, C. . . . . . . . . . . . . . . . . . .56Rautenberg, J. . . . . . . . . . 340Ravachol, M. . . . . . . . . . . . 370Reboul, E. . . . . . . . . . . . . . 168Reichl, H. . . . . . . . . . . . . . . 212Rembert, P. . . . . . . . . . . . . 232Remmers, H. . . . . . .220, 391Renard, C. . . . . . . . . . . . . . 223Rene, P.-J. . . . . . . . . . . . . . 117Renner, C.. . . . . . . . . . . . . . .59Renz, J. . . . . . . . . . . . . . . . . 410Rezeau, G. . . . . . . . . . . . . . . 56Ribay, G. . . . . . . . . . . . . . . . . 58Ribeiro, M. . . . . . . . . . . . . . 253Richard, F. . . . . . . . . . . . . . 140Richoux, O. . . . . . . . . . . . . 235Richter, B.. . . .104, 193, 196Richter, D. . . . . . . . . . . . . . .145Richter, I. . . . . . . . . . . . . . . 291Ricot, D.. . . . . . . . . . . . . . . .299Riedlinger, R. . . . . . . . . . . 282Riegel, M. . . . . . . . . . . . . . . 303Riemann, Daniel, 119, 252Riemann, Dieter, 376Rigoll, G. . . . . . . . . . . . . . . .390Ritty, A. . . . . . . . . . . . . . . . . 349Robin, B. . . . . . . . . . . . . . . . . 78Roche, R. . . . . . . . . . . . . . . 369Rodriguez-Ahlquist, J. . . . 52Roentgen, C. . . . . . . . . . . .125Roger, M. . . . . . . . . . . . . . . 300Ronneberger, D. . . . . 86, 147Rosenberger, F..64, 65, 220Rosenthal, V. . . . . . . . . . . .382Rossi, M. . . . . . . . . . . . . . . . . 48Rossignol, C. . . . . . . . . . . . . 92Roussarie, V. . . . . . . . . . . .140Roux, C.. . . . . . . . . . . . . . . . .58

Roy, A. . . . . . . . . . . . . . . . . . 267Royer, D. . . . . . . 90, 153, 155Ruchkin, S. . . . . . . . . . . . . 306Rutishauser, G. . . . . . . . . 381Rychagov, M. . . . . . . . . . . 306Röseler, H. . . . . . . . . . . . . . 198

Sabatié, G. . . . . . . . . . . . . .311Sabra, M.N. . . . . . . . . . . . . 294Sadiki, A. . . . . . . . . . . . . . . . . 82Saemann, U. . . . . . . . . . . . 123Saez, A. . . . . . . . . . . . . . . . 443Saied, M. . . . . . . . . . . . . . . 441Sakout, A. . . . . . . . . . . . . . .298Salah El Din, I. . . . . . . . . . 371Salmon, S. . . . . . . . . . . . . . 432Salvucci, A. . . . . . . . . . . . . 266Sampic, J. . . . . . . . . . . . . . .362Santiago, O.F. . . . . . . . . . . 159Sarlat, L. . . . . . . . . . . . . . . . 112Sarradj, E.53, 168, 192, 405Sas, P. . 127, 150, 151, 165,

305Satriadarma, B. . . . . . . . . 149Sattelmayer, T. . . . . . . . . . . 84Savel, S. . . . . . . . . . . . . . . . 205Schack, T. . . . . . . . . . . . . . .255Schael, S. . . . . . . . . . . . . . . 171Schaffner, M. . . . . . . . . . . .186Schanz, D. . . . . . . . . 245, 247Schanz, M. . . . . . . . . . . . . .162Schapkin, S. . . . . . . . . . . . 111Schaupp, M. . . . . . . . . . . . 341Scheck, Jochen, 103, 195Schellekens, M.H. . . . . . . 352Schemel, C. . . . . . . . . . . . . . 81Schick, A. . . . . . . . . . . . . . . 108Schierz, C. . . . . . . . . 379, 395Schimmel, O.. . . . . . . . . . .420Schirmacher, R. . . . . . . . . 153Schlachter, I. . . . . . . . . . . . 186Schlittmeier, S. . . . . . . . . . 313Schmich, I. . . . . . . . . . . . . . 132Schmid, A. . . . . . . . . . . . . . 107Schmid, C. . . . . . . . . . . . . . 394Schmidmer, C. . . . . . . . . . . 62Schmidt, L. . . . . . . . . . . 74, 75

Schmidt, S. . . . . . . . . . . . . 317Schmidtke, E. . . . . . . . . . . 160Schmitt, P. . . . . . . . . . . . . . 405Schmitz, A. . . . . . . . . . . . . . . 99Schneider, M. . . . . . . . . . . 195Schneider, W. . . . . . 406, 417Schnelle, F. . . . . . . . . . . . . 296Schoenwald, S. . . . . . . . . 102Scholl, W. . . . . . . . . . . . . . . . 99Schomer, P. . . . . . . . 183, 397Schoolmaster, M. . . . . . . 113Schröder, H. . 104, 193, 196Schröder, W. . . . . . . . . . . . . 83Schröger, E.. . . . . . . . . . . .208Schulte-Fortkamp, B. . . 177,

179, 230Schultz, M. . . . . . . . . . . . . . 136Schulz, D. . . . . . . . . . . . . . . 175Schulz, J. . . . . . . . . . 149, 301Schulz, V. . . . . . . . . . . . . . . . 49Schulze, C.. . . . . . . .145, 306Schwartz, D. . . . . . . . . . . . 207Schwartzenberger, A. . .296,

297Schwarz-Röhr, B. . 170, 240,

346Schwarze, S. . . . . . . 182, 183Schönfelder, R. . . . . . . . . .314Schürmann, C. . . . . . . . . . 109Schütte, M. . . . . . . . . . . . . .109Sciamarella, D. . . . . . . . . . 352Scott, J. . . . . . . . . . . . . . . . . 369Sebaa, N. . . . . . . . . . . . . . . 436Seeber, B. . . . . . . . . . . . . . 115Segaud, L. . . . . . . . . . . . . . 140Sehrndt, G. . . . . . . . . . . . . 324Seidel, J. . . . . . . . . . . . . . . . 194Sellerbeck, P. 119, 229, 252Semidor, C. . . . . . . . . . . . . 178Sgard, F. . . . . . . . . . . . . . . . 274Shaira, M. . . . . . . . . . . . . . . 293Shinn-Cunningham, B. . 113Siefert, A. . . . . . . . . . . . . . . 152Siegmann, S. . . . . . 426, 427Siegmund, K. . . . . . 426, 427Silzle, A. . . . . . . . . . . . . . . . 399Simon, L. . . . . . . . . . . . . . . 238

Simpson, J. . . . . . . . . . . . . 324Sitel, A. . . . . . . . . . . . . . . . . . 94Skowronek, J. . . . . . . . . . . 386Sköld, A. . . . . . . . . . . . . . . . 311Slama, J.G. . . . . . . . . . . . . 416Solodov, I. . . . . . . . . 287, 291Sommer, J.-P. . . . . . . . . . . 213Sonnendrucker, E. . . . . . 432Sorgüven, E. . . . . . . . . . . . . 85Sornette, D. . . . . . . . . . . . . 293Sottek, R. 55, 119, 120, 252Soua, S. . . . . . . . . . . . . . . . 292Souchon, G. . . . . . . . . . . . 235Spehr, C. . . . . . . . . . . . . . . . . 70Sperlich, R. . . . . . . . . . . . . 260Späh, M. . . . . . . . . . . . . . . . 101Stapelfeldt, H. . . . . . . . . . . 361Starke, E. . . . . . . . . . . . . . . . 88Start, E. . . . . . . . . . . . . . . . . 271Steckel, R. . . . . . . . . . . . . . 106Stefanelli, R. . . . . . . 425, 426Steffens, C. . . . . . . . . . . . . 226Steger, H. . . . . . . . . . . . . . . 119Steinbacher, D. . . . . . . . . . . 50Stepanek, J. . . . . . . . . 78, 419Stephenson, U. . . . . . . . . 130Stiebel, D. . . . . . . . . . . . . . . 260Stoelinga, C. . . . . . . . . . . . 141Stoffers, J. . . . . . . . . . . . . . 354Stratmann, K. . . . . . . . . . . 435Straube, U. . . . . . . . . . . . . .337Streicher, A. . . . . . . . . . . . .338Stumpner, R. . . . . . .129, 253Sukowski, H. . . . . . . . . . . . 108Suner, B. . . . . . . . . . . . . . . . . 56Sunyach, M.. . . . . . . . . . . .372Susini, P. . . . . . 139, 257, 312Sust, C.A. . . . . . . . . . . . . . . 106Suzuki, Y. . . . . . . . . . . . . . . 333Sälzer, E. . . . . . . . . . . . . . . 194

Tanter, M. . . . . . . . . . . . . . . 231Tardieu, J. . . . . . . . . . . . . . .257Taschke, H. . . . . . . . 279, 280Tebec, J.L. . . . . . . . . 402, 414Tebje, L.. . . . . . . . . . . . . . . .215Teller, P. . . . . . . . . . . . . . . . . 408

Tennhardt, H.-P. . . . 130, 133Tervo, T.. . . . . . . . . . .249, 251Teston, F. . . . . . . . . . . . . . . 232Teuber, W. . . . . . . 55, 60, 133Teyssandier, B. . . . . . . . . . 238Thaden, R. . . . . . . . . . . . . . 192Theile, G. . . . . . . . . . 327, 357Thiele, F. . . . . . . . . . . . . . . . . 81Thiele, R. . . . . . . . . . . . . . . 224Thomas, J.-H. . 76, 273, 275Thomas, J.-L. . . . . . 245, 365Tippkemper, R. . . . . . . . . .406Torrésani, B. . . . . . . . . . . . 277Tourin, A. . . . . . . . . . . . . . . 435Tournat, V. . . . 156, 239, 441Tournour, M. . . . . . . . . . . . 159Trautmann, U. . . . . . 319, 322Trimpop, M.. . . . . . . . . . . . . .69Trompette, N. . . . . . . . . . . 193Trompette, P. . . . . . . . . . . . 436

Unterberger, W. . . . . . . . . 383Uppenkamp, S.. . . . . . . . .351

Valeau, V. . . . . . . . . . . . . . . 298Valenzuela, M. . . . . . . . . . 376Valiere, J.-C. . . . . . . . . . . . 303Van Cauwelaert, J. . . . . . 282Van De Par, S. . . . .332, 385,

386Van Der Biest, F. . . . . . . . 435Van Hirtum, A. . . . . . . . . . 352Van Renterghem, T. . . . . 347Vandepitte, D. . . . . . . . . . . 165Vander Meulen, F. . . . . . . 289Vanmaele, C.. . . . . . . . . . .165Varnier, J. . . . . . . . . . . . . . . . 84Vary, P. . . . . . . . . . . . . . . . . .217Venghaus, H.. . . . . . . . . . .127Veres, E. . . . . . . . . . . . . . . . 342Verhey, J. . . . . . . . . . . . . . . 200Vian, J.-P. . . . . . . . . . 132, 134Viaud-Delmon, I. . . . . . . . 112Vicinus, P. . . . . . . . . . . . . . . 215Vignon, F. . . . . . . . . . . . . . . 443Vila, M. . . . . . . . . . . . . . . . . 289Ville, J.-M. . . . . . . . . . . . . . . . 94

Villot, M. . . . . . . . . . . . . . . . 384Viollon, S. . . . . . . . . . . . . . . 186Vjästfäll, D. . . . . . . . . . . . . . 182Voelker, E.-J. . . . . . . . . . . . . 60Vogel, C. . . . . . . . . . . . . . . . 187Vogelsang, B. . . . . . 322, 323Von Estorff, O. .49, 163, 169Von Wedel, H. . . . . .412, 413Vorraber, M. . . . . . . . . . . . . 225Vugt, J. . . . . . . . . . . . . . . . . . . 62Västfjäll, D. . . . . . . . .311, 334Vöhringer, T.. . . . . . . . . . . . .53Völker, E.-J. . . . . . . . . 55, 133

Wack, R. . . . . . . . . . . . . . . . 409Wackerl, J. . . . . . . . . . . . . . 287Wagener, K. . . . . . . . . . . . .315Walger, M. . . . . . . . . 412, 413Walker, E. . . . . . . . . . 396, 397Warnecke, V. . . . . . . . . . . . 136Warusfel, O. . . 61, 112, 335,

358Waubke, H. . . . . . . . 170, 222Weber, L. . . . . . . . . . 407, 408Weber, R. . . . 122, 310, 391,

415Weihnacht, M.. . . . .336, 337Weistenhöfer, C. . . . . . . . 214Weißing, H. . . . . . . . . . . . . 216Wells, R. . . . . . . . . . . . . . . . 297Wettschureck, R. . . . . . . . 385Wetzel, E. . . . . . . . . . . . . . . 360Wickelmaier, F. . . . . . . . . . 394Wiegrebe, L. . . . . . . . . . . . 199Wiemeler, D. . . . . . . . . . . . 330Wiggers, R. . . . . . . . . . . . . 348Wik, T. . . . . . . . . . . . . . . . . . 344Wilde, A. . . . . . . . . . . . . . . . . 60Wilkens, V. . . . . . . . . 174, 336Winkler, A. . . . . . . . . . . . . . . 84Winsberg, S. . . . . . . . . . . . 312Winter, B. . . . . . . . . . . . . . . 224Wirth, K. . . . . . . . . . . 379, 395Witew, I. . . . . . . . . . . . . . . . .132Wittek, H. . . . . . . . . . . . . . . 357Wittstock, V. . . . . . . . . . . . . . 97Wolfe, J. . . . . . . . . . . . . . . . . . 77

Wolff, K. . . . . . . . . . . . . . . . .227Wolff, O. . . . . . . . . . . 119, 120Woloszyn, P.. . . . . . . . . . . . .56Woolley, A. . . . . . . . . . . . . . 343Wullens, F. . . . . . . . . . . . . . 125Wurzel, D. . . . . . . . . . . . . . . 104Wurzinger, G. . . . . . . . . . . 284Wäsle, J. . . . . . . . . . . . . . . . . 84

Yankonis, M. . . . . . . . . . . . . .98

Zaitsev, V. . . . . . . . . . . . . . . 156Zakharia, M. . . . . . . . . . . . 197Zaleski, O.. . . . . . . . . .49, 169Zangers, J. . . . . . . . . . . . . . 243Zannin, P. . . . . . . . . . . . . . . 407Zarzalis, N. . . . . . . . . . . . . .444Zeibig, A. . . . . . .86, 145, 306Zeitler, A. . . . . . . . . . . . . . . 318Zeitler, B. . . . . . . . . . . . . . . 274Zerbs, C. . . . . . . . . . . . . . . . 314Zha, X. . . . 58, 96, 135, 272,

409, 417Zhang, J. . . . . . . . . . . . . . . .126Zhang, V. . . . . . . . . . . . . . . 440Zhou, X. . . . 58, 96, 135, 409Zickmantel, F. . . . . . . 56, 406Ziegenhals, G. . . . . . . . . . 375Ziemann, A. . .400, 428–430Zimmermann, S.. . . . . . . . .71Zimpfer-Jost, V. . . . . .72, 404Zoghaib, L. . . . . . . . . . . . . . 164Zucchini, M. . . . . . . . . . . . . 305


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