Auditory filters were derived in 20 normal-hearing human listeners at center frequencies (CFs) of 913, 1095, 3651, and 4382 Hz using the roex (p,r) method. Comparisons were made between slopes of the filters' skirts at the neighboring CFs with filter output levels of 45 and 70 dB. The same comparisons were made with regard to filter equivalent rectangular bandwidth (ERB). In the 1000-Hz region, the low-frequency slopes (Pl) of filters centered at 913 and 1095 Hz were significantly correlated at both stimulus levels, while the high-frequency slopes (Pu) were similar only at the high test level. In the 4000-Hz region, for sinusoids of 3651 and 4382 Hz, the level effect was clearer as both Pu and Pl values diverged at the low level but were related at high levels. The ERBs centered at the same CFs displayed a similar level dependence. At the stimulus level most likely to be affected by an active feedback mechanism, auditory filters centered at nearly the same frequency displayed quite distinct frequency selectivity, and this trend was stronger in the 4000-Hz region than the 1000-Hz region. The findings suggest that a saturating, active cochlear mechanism may not be distributed evenly, or contribute to peripheral tuning with equal effectiveness throughout the length of the partition.

The aim of the study was to examine central auditory processes compromised by age, age-related hearing loss, and the presentation of a distracting cafeteria noise using auditory event-related potentials (ERPs). In addition, the relation of ERPs to behavioral measures of discrimination was investigated. Three groups of subjects participated: young normal hearing, elderly subjects with normal hearing for their age, and elderly hearing-impaired subjects. Psychoacoustic frequency discrimination thresholds for a 1000-Hz pure tone were determined in quiet and in the presence of a contralateral cafeteria noise. To elicit ERPs, small frequency contrasts were presented with and without noise under unattended and attended conditions. In the attended condition, behavioral measures of d′ detectability and reaction times were also obtained. Noise affected all measures of behavioral frequency discrimination significantly. Except N1, all ERP components in the standard and difference waveforms decreased significantly in amplitude and increased in latency to the same degree in all three subject groups, arguing against a specific age-related sensitivity to the effects of contralateral background noise. For N1 amplitude, the effect of noise was different in the three subject groups, with a complex interaction of age, hearing loss, and attention. Behavioral frequency discrimination was not affected by age but deteriorated significantly in the elderly subjects with hearing loss. In the electrophysiological test, age-related changes occurred at various levels. The most prominent finding in the response to the standard stimuli was a sustained negativity (N2) following P2 in the young subjects that was absent in the elderly, possibly indicating a deficit in the inhibition of irrelevant information processing. In the attended difference waveform, significantly larger N2b and smaller P3b amplitudes and longer N2b and P3b latencies were observed in the elderly indicating different processing strategies. The pronounced age-related changes in the later cognitive components suggest that the discrimination of difficult contrasts, although behaviorally maintained, becomes more effortful in the elderly.

This doctoral thesis is the result of a research effort performed in two fields of speech technology, i.e., speech recognition and mispronunciation detection. Although the two areas are clearly distinguishable, the proposed approaches share a common hypothesis based on psychoacoustic processing of speech signals. The conjecture implies that the human auditory periphery provides a relatively good separation of different sound classes. Hence, it is possible to use recent findings from psychoacoustic perception together with mathematical and computational tools to model the auditory sensitivities to small speech signal changes. The performance of an automatic speech recognition system strongly depends on the representation used for the front-end. If the extracted features do not include all relevant information, the performance of the classification stage is inherently suboptimal. The work described in Papers A, B and C is motivated by the fact that humans perform better at speech recognition than machines, particularly for noisy environments. The goal is to make use of knowledge of human perception in the selection and optimization of speech features for speech recognition. These papers show that maximizing the similarity of the Euclidean geometry of the features to the geometry of the perceptual domain is a powerful tool to select or optimize features. Experiments with a practical speech recognizer confirm the validity of the principle. It is also shown an approach to improve mel frequency cepstrum coefficients (MFCCs) through offline optimization. The method has three advantages: i) it is computationally inexpensive, ii) it does not use the auditory model directly, thus avoiding its computational cost, and iii) importantly, it provides better recognition performance than traditional MFCCs for both clean and noisy conditions. The second task concerns automatic pronunciation error detection. The research, described in Papers D, E and F, is motivated by the observation that almost all native speakers perceive, relatively easily, the acoustic characteristics of their own language when it is produced by speakers of the language. Small variations within a phoneme category, sometimes different for various phonemes, do not change significantly the perception of the language’s own sounds. Several methods are introduced based on similarity measures of the Euclidean space spanned by the acoustic representations of the speech signal and the Euclidean space spanned by an auditory model output, to identify the problematic phonemes for a given speaker. The methods are tested for groups of speakers from different languages and evaluated according to a theoretical linguistic study showing that they can capture many of the problematic phonemes that speakers from each language mispronounce. Finally, a listening test on the same dataset verifies the validity of these methods. / <p>QC 20120914</p> / European Union FP6-034362 research project ACORNS / Computer-Animated language Teachers (CALATea)

This dissertation is about sound in context. Since sensory processing is inherently multimodal, research in sound is necessarily multidisciplinary. The present work has been guided by principles of systematicity, ecological validity, complementarity of  methods, and integration of science and art. The main tools to investigate the mediating relationship of people and environment through sound have been empiricism and psychophysics. Four of the seven included papers focus on perception. In paper A, urban soundscapes were reproduced in a 3D installation. Analysis of results from an experiment revealed correlations between acoustic features and physiological indicators of stress and relaxation. Paper B evaluated soundscapes of different type. Perceived quality was predicted not only by psychoacoustic descriptors but also personality traits. Sound reproduction quality was manipulated in paper D, causing two effects on source localisation which were explained by spatial and semantic crossmodal correspondences. Crossmodal correspondence was central in paper C, a study of colour association with music. A response interface employing CIE Lab colour space, a novelty in music emotion research, was developed. A mixed method approach supported an emotion mediation hypothesis, evidenced in regression models and participant interviews. Three papers focus on design. Field surveys and acoustic measurements were carried out in restaurants. Paper E charted relations between acoustic, physical, and perceptual features, focussing on designable elements and materials. This investigation was pursued in Paper F where a taxonomy of sound sources was developed. Analysis of questionnaire data revealed perceptual and crossmodal effects. Lastly, paper G discussed how crossmodal correspondences facilitated creation of meaning in music by infusing ecologically founded sonification parameters with visual and spatial metaphors. The seven papers constitute an investigation into how sound affects us, and what sound means to us. / Denna doktorsavhandling handlar om ljud i sammanhang. Eftersom informationsbehandling genom sinnena alltid är multimodal så kräver ljudforskning en tvärvetenskaplig forskningsansats. Arbetet i denna avhandling har vägletts av principer såsom systematik, ekologisk validitet, samspel mellan metoder, och integration av vetenskap och konst. De viktigaste redskapen för att undersöka den ömsesidiga påverkan mellan människa och miljö genom ljud har varit empiri och psykofysik.Fyra artiklar handlar om perception. I artikel A återskapades urbana ljudlandskap i en 3D-ljudinstallation. Analys av experimentresultat avslöjade samband mellan akustiska mått och fysiologiska markörer av stress och avslappning.  Artikel B utvärderade olika typer av ljudlandskap. Upplevd kvalitet kunde prediceras inte bara av psykoakustiska mått utan även av personlighetsdrag. Ljudåtergivningskvalitet manipulerades i artikel D och orsakade två effekter på lokalisering av en ljudkälla vilka förklarades av rumslig och semantisk korsmodala kopplingar. Korsmodalitet var huvudpunkten i artikel C, en studie av färgassociation till musik. Ett användargränssnitt utvecklades som använder färgrymden CIE Lab, en nyhet i forskningfältet musik och känslor. En abduktiv metod stödde hypotesen att känslouttryck medierar korsmodala kopplingar, vilket framgick av regressionsmodeller och intervjuer med försökspersonerna.Tre artiklar handlar om design. Fältundersökningar och ljudmätningar utfördes i restauranger. Artikel E kartlade samband mellan akustiska, fysiska och perceptuella särdrag, med fokus på formbara element och material. Detta arbete fortsattes i artikel F varigenom en taxonomi av ljudkällor utvecklades. Analys av enkätdata avslöjade perceptuella och korsmodala effekter. Slutligen, artikel G diskuterade hur korsmodala kopplingar främjade meningsskapande i musik genom att ekologiskt motiverade sonifikationsparametrar samverkade med visuella och spatiala uttryck. De sju artiklarna utgör landmärken i avhandlingens utforskande av hur ljud påverkar oss, och vad ljud betyder för oss. / <p>QC 20151118</p>

Le diagnostic de l’acouphène repose sur le rapport verbal du patient. Cependant, les paramètres psychoacoustiques, tels que la hauteur et la sonie de l’acouphène, sont essentiels pour l’évaluation et pour discriminer les fausses plaintes. Quantifier le percept de l’acouphène reste un objectif de recherche important. Nous avons cherché à: (1) évaluer la précision d'une nouvelle méthode d'évaluation des acouphènes du type « likeness rating » avec une méthode de présentation continue de la hauteur, en considérant la formation musicale, et (2) vérifier si les mesures psychoacoustiques de l’acouphène ont la sensibilité et la spécificité pour détecter les personnes simulant un acouphène. Nous avons recruté des musiciens et des non-musiciens souffrant d'acouphènes et des simulateurs sans acouphènes. La plupart d’entre eux ont été testés une seconde fois quelques semaines plus tard. La hauteur de l’acouphène a d’abord été évaluée en utilisant la méthode « likness rating ». Des sons purs ont été présentés de manière aléatoire de 0.25 kHz à 16 kHz et les participants devaient coter la ressemblance de chaque son par rapport à leur acouphène, et en ajuster son volume de 0 à 100 dB SPL. La hauteur a ensuite été évaluée par une méthode, où les participants devaient apparier la hauteur de leur acouphène en déplaçant leur doigt sur une bande tactile générant des sons purs en continu de 0.5 kHz à 20 kHz par pas de 1 Hz. Les capacités à apparier des sons externes ont été évaluées en utilisant cet appareil. La hauteur prédominante de l’acouphène était similaire entre les deux méthodes pour les musiciens et les non-musiciens, bien que les musiciens montraient de meilleures capacités d’appariement face à des sons externes. Les simulateurs ont coté la sonie bien au-dessus que les autres groupes avec un grand degré de spécificité (94,4%), et ont été inconsistants dans l’appariement de cette sonie (pas de la hauteur) d’une session à une autre. Les données de la seconde session montrent des réponses similaires pour l’appariement de la hauteur pour les deux méthodes ainsi que pour tous nos participants. En conclusion, la hauteur et la sonie correspondent au percept de l’acouphène et doivent en plus être utilisées avec des échelles visuelles analogiques, qui sont plus corrélées avec la gêne et la détresse. Enfin, l’appariement de la sonie est sensible et spécifique à déterminer la présence de l’acouphène. / The diagnosis of tinnitus relies on self-report. Psychoacoustic measurements of tinnitus pitch and loudness are essential for assessing and discriminating true claims from false. For this reason, the quantification of tinnitus remains a challenging research goal. We aimed to: (1) assess the precision of a new tinnitus likeness rating procedure with a continuous pitch presentation method, controlling for music training, and (2) test whether tinnitus psychoacoustic measurements have the sensitivity and specificity required to detect people faking tinnitus. Musicians and non-musicians with tinnitus, and simulated malingerers without tinnitus were tested. Most were retested several weeks later. Tinnitus pitch matching was first assessed using the likeness rating method: Pure tones between 0.25 to 16 kHz were presented randomly to participants who had to rate the likeness of each tone to their tinnitus, and to adjust its loudness from 0 to 100 dB SPL. Tinnitus pitch matching was then assessed with a continuous pitch method. Participants had to match the pitch of their tinnitus by moving their finger across a touch sensitive strip, which generated a continuous pure tone from 0.5 to 20 kHz in 1 Hz step. Pitch matching abilities to external tones were assessed using this device. The predominant tinnitus pitch was consistent across the two methods for both musicians and non-musicians, although musicians displayed better external tone pitch matching abilities. Simulated malingerers rated loudness much above the other groups with a high degree of specificity (94.4%) and were unreliable in loudness (not pitch) matching from one session to the other. Retest data showed similar pitch matching responses for both methods for all participants. In conclusion, tinnitus pitch and loudness reliably corresponds to the tinnitus percept and psychoacoustic loudness matches are sensitive and specific to the presence of tinnitus. Furthermore, this novel method should be used along with visual analog scales, which are more correlated to mood and distress.

Thesis (Au.D.)--James Madison University, 2010. / Includes bibliographical references.

Thesis (Au.D.)--James Madison University, 2010. / Includes bibliographical references.

Ce travail se situe dans le cadre de la recherche de systèmes de notation permettant de transcrire de façon symbolique l’aspect concret et sensoriel, et non seulement abstrait et structurel, des artefacts de la musique par ordinateur. Dans ce but, nous exposons tout d’abord un modèle formel complet et minimal des objets et structures audionumériques, en référence aux critères de la perception ; ce modèle est implémenté sous la forme d’un langage fonctionnel Turing-potent qui permet d’effectuer l’équivalence entre l’expression mathématique d’un signal et sa réalisation informatique. Puis, nous employons ce formalisme afin d’exprimer un ensemble de critères de synthèse sonore, ce qui donne lieu à un logiciel de synthèse dont l’expressivité est considérable. Ces outils sont organisés suivant le schéma des théories Schaefferiennes, par une décomposition catégorielle dans laquelle les paramètres correspondent à des notions morphologiques. Finalement, nous rendons compte d’une série d’expériences visant à évaluer la pertinence de ces critères dans l’audition humaine, avec le concours d’un musicologue, puis sur un ensemble de sujets, et enfin vis-à-vis d’un public aussi large que possible. Ceci nous conduit à remettre en question la méthodologie la plus adéquate pour traiter ce type de problème, qui nous rapproche des sciences humaines et sociales, et suggère une démarche de science participative. / This piece of work is situated in the context of research on notation systems enabled to transcribe symbolically the concrete and sensorial aspect, and not only the abstract and structural aspect, of computer music artefacts. In this perspective, we first expose a complete and minimal formal model for digital audio objects and structures, relatively to the criteria of perception ; this model is implemented as a Turing-potent functional language, that draws the correspondance between the mathematical expression of a signal and its computational realisation. Then, we apply this formal construction to the expression of a number of schemes for sound synthesis, producing a software synthetiser whose expressivity is consequent. These tools are organised following the lines of Schaefferian theories, through a decomposition into categories whose parameters correspond with morphological notions. Finally, we draw the conclusions of a series of experiments aiming to evaluate the relevance of those schemes in human hearing, with the assistance of a musicologist, then with a number of subjects, and eventually by associating a public that is as wide as possible. This leads us to question the methodology most appropriate to tackle this kind of problem, which brings us closer to social science, and suggests a participative science approach.

No description available.

La musique du jeu MMORPG (« Massively Multiplayer Online Role-Playing Game ») World of Warcraft de la compagnie Blizzard Entertainment est prise comme modèle pour démontrer comment le timbre (instrumental et orchestral), en parallèle avec l’image, peut représenter des éléments de l’environnement virtuel. Dans un premier volet de l’analyse, une approche tripartite privilégiant l’observation des niveaux neutre, poïétique et esthésique est utilisée pour étudier les cas des trames musicales de trois régions du jeu : Dun Morogh (montagnes enneigées), Stranglethorn Vale (jungle tropicale) et Uldum (désert aride). L’instrumentation et l’orchestration de ces musiques sont étudiées pour déterminer en quoi le timbre peut se faire la représentation métaphorique de certaines caractéristiques d’un environnement naturel. Des entrevues menées auprès de compositeurs et un sondage soumis à des joueurs servent à vérifier la pertinence des résultats des analyses. Un autre volet de l’étude s’attarde à la manière avec laquelle le timbre, et plus particulièrement la symbolique qui lui est culturellement attribuée, est sollicité dans la construction de l’identité de peuples imaginaires. La musique représentative de quatre peuples de World of Warcraft est analysée en ce sens, soit celle des « Humans », des « Orcs », des « Tauren » et des « Blood Elves ». En conclusion, le timbre apparaît comme un important vecteur de signification s’inscrivant dans un processus d’amorçage qui, lui, contribue à ancrer la signification de l’image et à favoriser l’immersion du joueur en plus de stimuler son appréciation esthétique du jeu. / Music from Blizzard Entertainment’s infamous MMORPG (Massively Multiplayer Online Role-Playing Game) World of Warcraft is analyzed in order to illustrate how instrumental and orchestral timbre, along with image, can represent various elements of the virtual environment shown on screen. For the first part of the analysis, a tripartite approach requiring the study of the neutral, poietic, and esthesic levels is used. The music of three zones of the game is analyzed, namely that of Dun Morogh (snowy mountains), Stranglethorn Vale (tropical jungle), and Uldum (arid desert). Instrumentation and orchestration are the main aspects studied to determine how timbre can metaphorically illustrate certain characteristics of a natural environment. Interviews with video game music composers, and a survey submitted to World of Warcraft players helped to verify the relevance of our results. The second part of this study takes a look at how the symbolism culturally attributed to timbre intervenes in the construction of the identity of imaginary peoples. In this regard, the musical themes of four different peoples taken from the World of Warcraft universe are analyzed, namely that of the Humans, the Orcs, the Tauren, and the Blood Elves. In conclusion, timbre appears as an important source of meaning that, through a priming process, contributes to the anchoring of the image’s meaning. Moreover, it most likely facilitates the players’ immersion as well as their aesthetic appreciation of the game.