The perception of the direction of a sound source in the horizontal plane is largely dependent upon the relative arrival times of salient points in the waveform and upon the difference in amplitude at the two ears. Other effects such as binaural release from masking are mediated mainly by the percept of lateralisation. In an extensive literature review the major experiments in binaural unmasking. discrimination and lateralisation are introduced and the most influential binaural detection and lateralisation models discussed. It is argued that these models are all cross-correlation mechanisms operating upon the differences between the firing patterns of the two auditory nerves. A study of the response of the binaural system to changes in its input would be a critical test of such models, so an experiment to measure the threshold of a static tone in noise with temporally varying Interaural phase was performed. The results suggest that binaural processing is slow. The extent of lateralisation of bandpass (10%) filtered clicks of both low and high frequencies was studied with various interaural time and amplitude differences. A novel feature of the research, apart from the scaling technique used, was that subjects were encouraged to listen for multiple images. These experiments are sensitive to the breakdown of sensory fusion, and so pose a severe test for binaural models. Very similar results at both low- (260 Hz) and high- (8000 Hz) frequencies suggest a common lateralisation mechanism operating primarily upon interaural onset time differences. A binaural model is proposed which extends existing cross-correlation models. Included is an auditory nerve model which adapts and saturates. The other new element is coincidence detectors with significant (1 ms) integration times, which more closely represent the temporal Integration properties of real neural networks. The inclusion of the auditory nerve model Is very succesful, but the extended coincidence detectors prove less helpful. A single channel excitatory-inhibitory model Is also discussed.

Thesis (Ph. D.)--School of Electrical and Information Engineering, Faculty of Engineering, University of Sydney, 2001. / Title from title screen (viewed 13 January 2009). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the School of Electrical and Information Engineering, Faculty of Engineering. Includes bibliographical references. Also available in print form.

Made available in DSpace on 2016-03-15T19:22:23Z (GMT). No. of bitstreams: 1 Helena Rodi Neumann.pdf: 13422269 bytes, checksum: ce11e30e375347489ae3599ab8586e30 (MD5) Previous issue date: 2014-01-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of this study is to evaluate the soundscape of Teodoro Sampaio Street, in the city of São Paulo, and its impact on quality of life of its users. The research involves both discussion about the control of urban noise, as the determination of the positive sounds that qualify and characterize the public space. First we undertake a literature review on urban soundscapes, their impacts on users, and nearby buildings. The proposal is to raise what has been said about the theme in Brazil, and cite some relevant research abroad. Some academic studies have addressed this issue in the country, but few showed some theoretical reflection on urban acoustics. In a second step, we intend to establish a theoretical foundation for understanding the behavior of sound in the external environment of the contemporary city. This is mainly based on the work of two key authors: Murray Schafer, who defined the concept of "Soundscape" in 1979, and Brandon LaBelle, proposing a recent study, 2010 on what it defines as acoustic territories. It follows with a presentation of noise analysis methods in urban areas. First it discusses graphical ways of presenting the urban sounds from technical noise maps, with equal loudness curves of intensity levels; to attractive and informative graphs and diagrams, enabling quick understanding of the acoustic situation of an urban stretch. Also demonstrates ways to quantify the noise sources, and characterize their noise, data that are essential for entry into specific software. This step also involves the presentation of a method for qualitative assessment of users, proposed in the book "Urban Sound Enviroment", the author Jian Kang. The following presents the analysis of urban street taken as a case study. Earlier develops a historical survey of the change of use of the territory, in xii order to characterize their role in the urban context. Furthermore, through the analysis of historical maps, check how this urban stretch was gradually consolidated. Then it goes to an assessment of current conditions, with the precise characterization of the surroundings, resulting in photographic essays and informative maps. The proposal is to collect all relevant data characterizing this location, which are fundamental to the deep understanding of its acoustic setting. The next step is to evaluate the quality of the soundscape. First, they are prepared "maps of sound events" based on acoustic observation of the site taken by the researcher. Then, are performed the objective measurements with sound level meters in situ, resulting in maps of analysis of intensity levels, considering the change of scenery from the week and Saturday. It follows with a qualitative assessment made based on interviews with the population, to verify the perception of urban and sound quality of the urban stretch. In conclusion, the results of all methods applied for acoustics and urban evaluation are related, to the central purpose of proving that the perception of urban quality is affected by sound intensity. / O objetivo deste trabalho é avaliar a paisagem sonora da Rua Teodoro Sampaio, na cidade de São Paulo, e o impacto desta na qualidade de vida dos seus usuários. A pesquisa envolve tanto a discussão sobre o controle de ruídos urbanos, quanto a determinação dos sons positivos que qualificam e caracterizam o espaço público. Primeiramente elabora-se uma revisão bibliográfica sobre paisagens sonoras urbanas, seus impactos nos usuários, e nas edificações próximas. A proposta é levantar o que já foi discutido sobre o tema no Brasil, e citar algumas pesquisas relevantes no exterior. Alguns trabalhos acadêmicos já abordaram este tema no pais, mas poucos apresentaram alguma reflexão teórica sobre a acústica urbana. Em um segundo momento pretende-se estabelecer uma fundamentação teórica para compreender o comportamento do som no ambiente externo da cidade contemporânea. Esta baseia-se principalmente no trabalho de dois autores centrais: Murray Schafer, que definiu o conceito de paisagem sonora ou Soundscape em 1979; e o Brandon LaBelle, que propõe um estudo recente, de 2010, sobre o que define como territórios acústicos. Segue-se com a apresentação das metodologias de análise dos ruídos em meio urbano. Primeiro discute-se meios gráficos de apresentar os sons urbanos, desde mapas de ruídos técnicos, com curvas isofônicas de níveis de intensidade; até gráficos e esquemas atrativos e informativos, que permitam a rápida compreensão da situação acústica de um trecho urbano. Também se demonstra formas de quantificar as fontes sonoras, e caracterizar seus ruídos; dados que são fundamentais para entrada em softwares específicos. Esta etapa envolve também a apresentação de um método de avaliação qualitativa dos usuários, proposta no livro Urban Sound Enviroment , do autor Jian Kang. x A seguir apresenta-se a análise urbana da rua tomada como estudo de caso. No início desenvolve-se um levantamento histórico da mudança de uso deste território, com o intuito de caracterizar seu papel no contexto urbano. Além disso, através da análise de mapas históricos da SMDU, verificar como este trecho foi progressivamente consolidado. Em seguida, passa-se para uma avaliação das condições atuais, com a precisa caracterização do entorno, que resulta em ensaios fotográficos e mapas informativos. A proposta é levantar todos os dados relevantes que caracterizam este local, que são fundamentais para a compreensão aprofundada do seu cenário acústico. O próximo passo é avaliar a qualidade da paisagem sonora. Primeiramente, são elaborados Mapas de eventos sonoros com base na observação do pesquisador da acústica do local. Em seguida, são realizadas as medições objetivas, com sonômetros in loco, que resultam em mapas de análise dos níveis de intensidade do local, considerando a mudança de cenário entre a semana e o sábado. Segue-se com a avaliação qualitativa, feita com base em entrevistas com a população, para verificar a percepção da qualidade urbana e sonora do trecho urbano. Como conclusão, os resultados de todos os métodos de avaliação acústica e urbana aplicados são relacionados, com o intuito central de comprovar que a percepção da qualidade urbana é impactada pela intensidade do som.

[ES] La reproducción de las propiedades espaciales del sonido es una cuestión cada vez más importante en muchas aplicaciones inmersivas emergentes. Ya sea en la reproducción de contenido audiovisual en entornos domésticos o en cines, en sistemas de videoconferencia inmersiva o en sistemas de realidad virtual o aumentada, el sonido espacial es crucial para una sensación de inmersión realista. La audición, más allá de la física del sonido, es un fenómeno perceptual influenciado por procesos cognitivos. El objetivo de esta tesis es contribuir con nuevos métodos y conocimiento a la optimización y simplificación de los sistemas de sonido espacial, desde un enfoque perceptual de la experiencia auditiva. Este trabajo trata en una primera parte algunos aspectos particulares relacionados con la reproducción espacial binaural del sonido, como son la escucha con auriculares y la personalización de la Función de Transferencia Relacionada con la Cabeza (Head Related Transfer Function - HRTF). Se ha realizado un estudio sobre la influencia de los auriculares en la percepción de la impresión espacial y la calidad, con especial atención a los efectos de la ecualización y la consiguiente distorsión no lineal. Con respecto a la individualización de la HRTF se presenta una implementación completa de un sistema de medida de HRTF y se introduce un nuevo método para la medida de HRTF en salas no anecoicas. Además, se han realizado dos experimentos diferentes y complementarios que han dado como resultado dos herramientas que pueden ser utilizadas en procesos de individualización de la HRTF, un modelo paramétrico del módulo de la HRTF y un ajuste por escalado de la Diferencia de Tiempo Interaural (Interaural Time Difference - ITD). En una segunda parte sobre reproducción con altavoces, se han evaluado distintas técnicas como la Síntesis de Campo de Ondas (Wave-Field Synthesis - WFS) o la panoramización por amplitud. Con experimentos perceptuales se han estudiado la capacidad de estos sistemas para producir sensación de distancia y la agudeza espacial con la que podemos percibir las fuentes sonoras si se dividen espectralmente y se reproducen en diferentes posiciones. Las aportaciones de esta investigación pretenden hacer más accesibles estas tecnologías al público en general, dada la demanda de experiencias y dispositivos audiovisuales que proporcionen mayor inmersión. / [CA] La reproducció de les propietats espacials del so és una qüestió cada vegada més important en moltes aplicacions immersives emergents. Ja siga en la reproducció de contingut audiovisual en entorns domèstics o en cines, en sistemes de videoconferència immersius o en sistemes de realitat virtual o augmentada, el so espacial és crucial per a una sensació d'immersió realista. L'audició, més enllà de la física del so, és un fenomen perceptual influenciat per processos cognitius. L'objectiu d'aquesta tesi és contribuir a l'optimització i simplificació dels sistemes de so espacial amb nous mètodes i coneixement, des d'un criteri perceptual de l'experiència auditiva. Aquest treball tracta, en una primera part, alguns aspectes particulars relacionats amb la reproducció espacial binaural del so, com són l'audició amb auriculars i la personalització de la Funció de Transferència Relacionada amb el Cap (Head Related Transfer Function - HRTF). S'ha realitzat un estudi relacionat amb la influència dels auriculars en la percepció de la impressió espacial i la qualitat, dedicant especial atenció als efectes de l'equalització i la consegüent distorsió no lineal. Respecte a la individualització de la HRTF, es presenta una implementació completa d'un sistema de mesura de HRTF i s'inclou un nou mètode per a la mesura de HRTF en sales no anecoiques. A mès, s'han realitzat dos experiments diferents i complementaris que han donat com a resultat dues eines que poden ser utilitzades en processos d'individualització de la HRTF, un model paramètric del mòdul de la HRTF i un ajustament per escala de la Diferencià del Temps Interaural (Interaural Time Difference - ITD). En una segona part relacionada amb la reproducció amb altaveus, s'han avaluat distintes tècniques com la Síntesi de Camp d'Ones (Wave-Field Synthesis - WFS) o la panoramització per amplitud. Amb experiments perceptuals, s'ha estudiat la capacitat d'aquests sistemes per a produir una sensació de distància i l'agudesa espacial amb que podem percebre les fonts sonores, si es divideixen espectralment i es reprodueixen en diferents posicions. Les aportacions d'aquesta investigació volen fer més accessibles aquestes tecnologies al públic en general, degut a la demanda d'experiències i dispositius audiovisuals que proporcionen major immersió. / [EN] The reproduction of the spatial properties of sound is an increasingly important concern in many emerging immersive applications. Whether it is the reproduction of audiovisual content in home environments or in cinemas, immersive video conferencing systems or virtual or augmented reality systems, spatial sound is crucial for a realistic sense of immersion. Hearing, beyond the physics of sound, is a perceptual phenomenon influenced by cognitive processes. The objective of this thesis is to contribute with new methods and knowledge to the optimization and simplification of spatial sound systems, from a perceptual approach to the hearing experience. This dissertation deals in a first part with some particular aspects related to the binaural spatial reproduction of sound, such as listening with headphones and the customization of the Head Related Transfer Function (HRTF). A study has been carried out on the influence of headphones on the perception of spatial impression and quality, with particular attention to the effects of equalization and subsequent non-linear distortion. With regard to the individualization of the HRTF a complete implementation of a HRTF measurement system is presented, and a new method for the measurement of HRTF in non-anechoic conditions is introduced. In addition, two different and complementary experiments have been carried out resulting in two tools that can be used in HRTF individualization processes, a parametric model of the HRTF magnitude and an Interaural Time Difference (ITD) scaling adjustment. In a second part concerning loudspeaker reproduction, different techniques such as Wave-Field Synthesis (WFS) or amplitude panning have been evaluated. With perceptual experiments it has been studied the capacity of these systems to produce a sensation of distance, and the spatial acuity with which we can perceive the sound sources if they are spectrally split and reproduced in different positions. The contributions of this research are intended to make these technologies more accessible to the general public, given the demand for audiovisual experiences and devices with increasing immersion. / Gutiérrez Parera, P. (2020). Optimization and improvements in spatial sound reproduction systems through perceptual considerations [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/142696

<p>Examensarbetet har finansierats av Interactive Institute Piteå med medel från strukturfondsprojektet LJUDIT. Arbetet har utförts på och handletts av Interactive Institute Piteå.</p> / LJUDIT

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