Дисертації з теми "Spatial sound perception"

Doutoramento em Música
This thesis explores the possibilities of spatial hearing in relation to sound perception, and presents three acousmatic compositions based on a musical aesthetic that emphasizes this relation in musical discourse. The first important characteristic of these compositions is the exclusive use of sine waves and other time invariant sound signals. Even though these types of sound signals present no variations in time, it is possible to perceive pitch, loudness, and tone color variations as soon as they move in space due to acoustic processes involved in spatial hearing. To emphasize the perception of such variations, this thesis proposes to divide a tone in multiple sound units and spread them in space using several loudspeakers arranged around the listener. In addition to the perception of sound attribute variations, it is also possible to create rhythm and texture variations that depend on how sound units are arranged in space. This strategy permits to overcome the so called "sound surrogacy" implicit in acousmatic music, as it is possible to establish cause-effect relations between sound movement and the perception of sound attribute, rhythm, and texture variations. Another important consequence of using sound fragmentation together with sound spatialization is the possibility to produce diffuse sound fields independently from the levels of reverberation of the room, and to create sound spaces with a certain spatial depth without using any kind of artificial sound delay or reverberation.
Esta tese explora as possibilidades da Audição Espacial em relação à percepção do som e apresenta três composições acusmáticas baseadas numa estética musical que enfatiza esta relação e a incorpora como uma parte do seu discurso musical. A primeira característica importante destas composições é a utilização exclusiva de sinusóides e de outros sinais sonoros invariáveis no tempo. Embora estes tipos de sinais não apresentem variações no tempo, é possível percepcionar variações de altura, intensidade e timbre assim que estes se movem no espaço, devido aos processos acústicos envolvidos na audição espacial. Para enfatizar a percepção destas variações, esta tese propõe dividir um som em múltiplas unidades e espalhá-las no espaço utilizando vários monitores dispostos à volta da plateia. Além da percepção de variações de características do som, também é possível criar variações de ritmo e de textura que dependem de como os sons são dispostos no espaço. Esta estratégia permite superar o problema de “sound surrogacy” implícito na música acusmática, uma vez que é possível estabelecer relações causa-efeito entre o movimento do som e a percepção de variações de características do som, variações do ritmo e textura. Outra consequênça importante da utilização da fragmentação com a espacialização do som é a possibilidade de criar campos sonoros difusos, independentemente dos níveis de reverberação da sala, e de criar espaços sonoros com uma certa profundidade, sem utilizar nenhum tipo de delay ou reverberação artificiais.

This thesis provides an overview of work conducted to investigate human spatial hearing in situations involving multiple concurrent sound sources. Much is known about spatial hearing with single sound sources, including the acoustic cues to source location and the accuracy of localisation under different conditions. However, more recently interest has grown in the behaviour of listeners in more complex environments. Concurrent sound sources pose a particularly difficult problem for the auditory system, as their identities and locations must be extracted from a common set of sensory receptors and shared computational machinery. It is clear that humans have a rich perception of their auditory world, but just how concurrent sounds are processed, and how accurately, are issues that are poorly understood. This work attempts to fill a gap in our understanding by systematically examining spatial resolution with multiple sound sources. A series of psychophysical experiments was conducted on listeners with normal hearing to measure performance in spatial localisation and discrimination tasks involving more than one source. The general approach was to present sources that overlapped in both frequency and time in order to observe performance in the most challenging of situations. Furthermore, the role of two primary sets of location cues in concurrent source listening was probed by examining performance in different spatial dimensions. The binaural cues arise due to the separation of the two ears, and provide information about the lateral position of sound sources. The spectral cues result from location-dependent filtering by the head and pinnae, and allow vertical and front-rear auditory discrimination. Two sets of experiments are described that employed relatively simple broadband noise stimuli. In the first of these, two-point discrimination thresholds were measured using simultaneous noise bursts. It was found that the pair could be resolved only if a binaural difference was present; spectral cues did not appear to be sufficient. In the second set of experiments, the two stimuli were made distinguishable on the basis of their temporal envelopes, and the localisation of a designated target source was directly examined. Remarkably robust localisation was observed, despite the simultaneous masker, and both binaural and spectral cues appeared to be of use in this case. Small but persistent errors were observed, which in the lateral dimension represented a systematic shift away from the location of the masker. The errors can be explained by interference in the processing of the different location cues. Overall these experiments demonstrated that the spatial perception of concurrent sound sources is highly dependent on stimulus characteristics and configurations. This suggests that the underlying spatial representations are limited by the accuracy with which acoustic spatial cues can be extracted from a mixed signal. Three sets of experiments are then described that examined spatial performance with speech, a complex natural sound. The first measured how well speech is localised in isolation. This work demonstrated that speech contains high-frequency energy that is essential for accurate three-dimensional localisation. In the second set of experiments, spatial resolution for concurrent monosyllabic words was examined using similar approaches to those used for the concurrent noise experiments. It was found that resolution for concurrent speech stimuli was similar to resolution for concurrent noise stimuli. Importantly, listeners were limited in their ability to concurrently process the location-dependent spectral cues associated with two brief speech sources. In the final set of experiments, the role of spatial hearing was examined in a more relevant setting containing concurrent streams of sentence speech. It has long been known that binaural differences can aid segregation and enhance selective attention in such situations. The results presented here confirmed this finding and extended it to show that the spectral cues associated with different locations can also contribute. As a whole, this work provides an in-depth examination of spatial performance in concurrent source situations and delineates some of the limitations of this process. In general, spatial accuracy with concurrent sources is poorer than with single sound sources, as both binaural and spectral cues are subject to interference. Nonetheless, binaural cues are quite robust for representing concurrent source locations, and spectral cues can enhance spatial listening in many situations. The findings also highlight the intricate relationship that exists between spatial hearing, auditory object processing, and the allocation of attention in complex environments.

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.

Recent advancements in audio technology for computer games has made possible for implementations with binaural audio. Compared to regular stereo sound, binaural audio offers possibilities for a player to experience spatial sound, including sounds along the vertical plane, using their own headphones. A computer game prototype called “Crystal Gatherer” was created for this study to explore the possibilities of binaural audio imple- mentation regarding localization and perception of objects that make sound in a 3D game. The game featured two similar game levels, with the difference that one used binaural sound, and the other stereo sound. The levels consisted of a dark space that the player could navigate freely with the objective to find objects that make sound, called “crystals”, as fast as they could. An experiment was conducted with 14 test sub- jects that played the game, qualitative and quantitative data was collected, including the time the players took to complete the game levels, respectively, and answers about how they experienced the levels. A majority of test subjects reported that they per- ceived a difference between the levels. No significant difference was found between the levels in terms of efficacy of finding the objects that made sound. Some test subjects stated that they found localization was better in the binaural level of the game, others found the stereo level to be better in this respect. The study shows that there can exist possibilities for binaural audio to change the perception of audio in computer games.

Le maintien de la stabilité posturale est généralement décrit comme le résultat de l’intégration de plusieurs modalités sensorielles : vision, proprioception, tactile plantaire et système vestibulaire. Bien qu’étant une source riche d’informations spatiales, l’audition a été très peut étudiée dans ce cadre. Dans cette thèse, nous nous sommes intéressés à l’influence spécifique du son sur la posture.La première partie de ces travaux concerne la mise en place et la caractérisation perceptive d’un système de spatialisation ambisonique d’ordre 5. Ce système permet de générer et de déplacer des sons dans tout l’espace 3D entourant l’auditeur, ainsi que de synthétiser des espaces sonores immersifs et réalistes.Ensuite, ce système a été utilisé comme un outil pour la génération de stimuli adaptés à l’étude de l’influence du son sur la posture. Ainsi, la posture debout statique de sujets jeunes et en bonne santé a été étudiée dans un ensemble de cinq expériences posturales. Les résultats de ces différentes études montrent que l’information auditive spatiale peut être intégrée dans le système de régulation posturale, et permettre aux sujets d’atteindre une meilleure stabilité posturale.Deux pistes sont évoquées pour interpréter cette stabilisation : d’un côté, l’utilisation des indices acoustiques pour construire une carte spatiale de l’espace environnant, représentation par rapport à laquelle les sujets peuvent se stabiliser ; de l’autre, des phénomènes d’intégration multi-sensorielle, où la modalité auditive permettrait de potentialiser l’intégration des différentes informations fournies par les autres modalités impliquées dans le contrôle postural
Postural control is known to be the result of the integration by the central nervous system of several sensory modalities. In the literature, visual, proprioceptive, plantar touch and vestibular inputs are generally mentioned, and the role of audition is often neglected, even though sound is a rich and broad source of information on the whole surroundind 3D space. In the frame of this PhD, we focused on the specific role of sound on posture. The first part of this work is related to the design, the set-up and the perceptual evaluation of a fifth order ambisonics sound spatialization system. This system makes it possible to generate and move sound sources in the 3D space surrounding the listener and also to synthesize immersive and realistic sound environments. Then, this sound spatialization system was used as a tool to generate sound stimuli used in five different postural tests. In these tests, we studied the static upright stance of young and healthy subjects. The results of these studies show that the spatial auditory information can be integrated in the postural control system, allowing the subjects to reach a better stability.Two complementary trails are proposed to explain these stabilizing effects. Firstly, the spatial acoustic cues can contribute to the building of a mental representation of the surrounding environment; given this representation, the subjects could improve their stability. Secondly, we introduce multisensory integration phenomena: the auditory component could facilitate the integration of the other modalities implied in the postural control system

Les terminaux mobiles offrent à ce jour des performances de plus en plus élevées (CPU, résolution de l’écran, capteurs optiques, etc.) Cela rehausse la qualité vidéo des services média, que ce soit pour le visionnage de contenu vidéo (streaming, TV, etc.) ou pour des applications interactives telles que le jeu vidéo. Mais cette évolution concernant l'image n'est pas ou peu suivie par l'intégration de systèmes de restitution audio de haute qualité dans ce type de terminal. Or, parallèlement à ces évolutions concernant l'image, des solutions de son spatialisé sur casque, à travers notamment la technique de restitution binaurale basée sur l'utilisation de filtres HRTF (Head Related Transfer Functions) voient le jour.Dans ce travail de thèse, nous nous proposons d’évaluer l’intérêt que peut présenter le son binaural lorsqu'il est utilisé sur une application mobile audiovisuelle. Une partie de notre travail a consisté à déterminer les différents sens que l’on pouvait donner au terme « application mobile audiovisuelle » et parmi ces sens ceux qui d’une part étaient pertinents et d’autre part pouvaient donner lieu à une évaluation comparative avec ou sans son binaural.Le couplage entre son binaural et visuel sur mobile occasionne en premier lieu une question d’ordre perceptive : comment peut-on organiser spatialement une scène virtuelle dont le son peut se déployer tout autour de l’utilisateur, et dont le visuel est restreint à un si petit écran ? La première partie de cette thèse est consacrée à cette question. Nous menons une expérience visant à étudier le découplage spatial possible entre un son binaural et un visuel rendus sur smartphone. Cette expérience révèle une forte tolérance de l’être humain face aux dégradations spatiales pouvant survenir entre les deux modalités. En particulier, l’absence d’individualisation des HRTF, ainsi qu’un très grand découplage en élévation ne semblent pas affecter la perception. Par ailleurs, les sujets semblent envisager la scène « comme si » ils y étaient eux-mêmes directement projetés, à la place de la caméra, et cela indépendamment de leur propre distance à l’écran. Tous ces résultats suggèrent la possibilité d’une association entre son binaural et visuel sur mobile dans des conditions d’utilisation proches du grand public.Dans la seconde partie de la thèse, nous tentons de répondre à la question de l’apport du binaural en déployant une expérience « hors les murs », dans un contexte plausible d’utilisation grand public. Trente sujets jouent dans leur vie quotidienne à un jeu vidéo de type Infinite Runner, développé pour l’occasion en deux versions, une avec du son binaural, et l’autre avec du son monophonique. L’expérience dure cinq semaines, à raison de deux sessions par jour. Ce protocole procède de la méthode dite "Experience Sampling Method", sur l’état de l’art de laquelle nous nous sommes appuyés. Nous calculons à chaque session des notes d’immersion, de mémorisation et de performance, et nous comparons les notes obtenues entre les deux versions sonores. Les résultats indiquent une immersion significativement meilleure pour le binaural. La mémorisation et la performance ne sont en revanche pas soumises à un effet statistiquement significatif du rendu sonore. Au-delà des résultats, cette expérience nous permet de discuter de la question de la validité des données en fonction de la méthode de déploiement, en confrontant notamment bien-fondé théorique et faisabilité pratique
In recent years, smartphone and tablet global performances have been increased significantly (CPU, screen resolution, webcams, etc.). This can be particularly observed with video quality of mobile media services, such as video streaming applications, or interactive applications (e.g., video games). However, these evolutions barely go with the integration of high quality sound restitution systems. Beside these evolutions though, new technologies related to spatialized sound on headphones have been developed, namely the binaural restitution model, using HRTF (Head Related Transfer Functions) filters.In this thesis, we assess the potential contribution of the binaural technology to enhance the quality of experience of an audiovisual mobile application. A part of our work has been dedicated to define what is an “audiovisual mobile application”, what kind of application could be fruitfully experienced with a binaural sound, and among those applications which one could lead to a comparative experiment with and without binaural.In a first place, the coupling of a binaural sound with a mobile-rendered visual tackles a question related to perception: how to spatially arrange a virtual scene whose sound can be spread all around the user, while its visual is limited to a very small space? We propose an experiment in these conditions to study how far a sound and a visual can be moved apart without breaking their perceptual fusion. The results reveal a strong tolerance of subjects to spatial discrepancies between the two modalities. Notably, the absence or presence of individualization for the HRTF filters, and a large separation in elevation between sound and visual don’t seem to affect the perception. Besides, subjects consider the virtual scene as if they were projected inside, at the camera’s position, no matter what distance to the phone they sit. All these results suggest that an association between a binaural sound and a visual on a smartphone could be used by the general public.In the second part, we address the main question of the thesis, i.e., the contribution of binaural, and we conduct an experiment in a realistic context of use. Thirty subjects play an Infinite Runner video game in their daily lives. The game was developed for the occasion in two versions, a monophonic one and a binaural one. The experiment lasts five weeks, at a rate of two sessions per day, which relates to a protocol known as the “Experience Sampling Method”. We collect at each session notes of immersion, memorization and performance, and compare the notes between the monophonic sessions and the binaural ones. Results indicate a significantly better immersion in the binaural sessions. No effect of sound rendering was found for memorization and performance. Beyond the contribution of the binaural, we discuss about the protocol, the validity of the collected data, and oppose theoretical considerations to practical feasibility

This thesis analyses if the change of auditory feedback can improve the effectiveness of performance in the interaction with a non-visual system, or with a system used by individuals with visual impairment. Two prototypes were developed, one with binaural audio and the other with stereo audio. The interaction was evaluated in an experiment where 22 participants, divided into two groups, performed a number of interaction tasks. A post-interview were conducted together with the experiment. The result of the experiment displayed that there were no great difference between binaural audio and stereo regarding the speed and accuracy of the interaction. The post-interviews displayed interesting differences in the way participants visualized the virtual environment that affected the interaction. This opened up interesting questions for future studies.

Virtual Reality (VR) is gaining more and more popularity as a research tool in the field of Human-Robot Interaction (HRI). To fully deploy the potential of VR and benefit HRI studies, we need to establish the basic understanding of the relationship between the physical, real-world interaction (Live) and VR. This study compared Live and VR HRI with a focus on proxemics, as proxemics preference can reflect comprehensive human intuition, making it suitable to be used to compare Live and VR. To evaluate the influence of different modalities in VR, virtual scenes with different visual familiarity and spatial sound were compared as well. Lab experiments were conducted with a physical Pepper robot and its virtual copy. In both Live and VR, proxemics preferences, the perception of the robot (competence and discomfort) and the feeling of presence were measured and compared. Results suggest that proxemic preferences do not remain consistent in Live and in VR, which could be influenced by the perception of the robot. Therefore, when conducting HRI experiments in VR, the perceptions of the robot need be compared before the experiments. Results also indicate freedom within VR HRI as different VR settings are consistent with each other.

L'objectif de cette thèse est l'optimisation de la qualité perçue de la reproduction sonore par un système audio multicanal, dans un contexte de salle d'écoute domestique. Les travaux de recherche présentés s'articulent selon deux axes. Le premier concerne l'effet de salle, et plus particulièrement les aspects physiques et perceptifs liés aux premières réflexions d'une salle. Ces éléments sont décrits spécifiquement, et une expérience psychoacoustique a été menée afin d'étendre les données disponibles quant à leur perceptibilité, c'est à dire leur capacité à modifier la perception du son direct, que ce soit en termes de timbre ou de localisation. Les résultats mettent en évidence la dépendance du seuil en fonction du type de stimulus, ainsi que son évolution en fonction de la configuration spatiale de l'onde directe et de la réflexion. Pour une condition donnée, le seuil de perceptibilité est décrit comme une fonction de directivité dépendant de l'incidence de la réflexion.Le deuxième axe de travail concerne les méthodes de correction de l'effet de la salle de reproduction. Les méthodes numériques classiques sont d'abord étudiées. Leur principale lacune réside dans l'absence de prise en compte du rôle spécifique des propriétés temporelles et spatiales des première réflexions. Le travail de thèse se termine par la proposition d'une nouvelle méthode de correction utilisant un algorithme itératif de type FISTA modifié afin de prendre en compte la perceptibilité des réflexions. Le traitement est implémenté dans une représentation où l'information spatiale est analysée sur la base des harmoniques sphériques
The goal of this Ph. D. thesis is to optimize the perceived quality of multichannel sound reproduction systems, in the context of a domestic listening room. The presented research work have been pursued in two different directions.The first deals with room effet, and more particularly with physical and perceptual aspects of first reflections within a room. These reflections are specifically described, and a psychoacoustical experiment have been carried out in order to extend the available data on their perceptibility, i.e. their potency in altering the perception of the direct sound, whether in its timbral or spatial features. Results exhibit the variation of the threshold depending on the type of stimulus, as well as on the spatial configuration of the direct sound and the reflection. For a given condition, the perceptibility threshold is given as a directivity function depending on the direction of incidence of the reflection.The second topic deals with room correction methods. Firstly, state-of-the art digital methods are investigated. Their main drawback is that they don't consider the specific impact of the temporal and spatial attributes of first reflections. A new correction method is therefore proposed. It uses an iterative algorithm, derivated from the FISTA method, in order to take into account the perceptibility of the reflections. All the processing is carried out in a spatial sound representation, where the spatial properties of the sound are analysed thanks to spherical harmonics

Dans cette thèse, nous proposons la mise en place d'un système de réalité augmentée fondé sur le son 3D et la sonification, ayant pour objectif de fournir les informations nécessaires aux non- voyants pour un déplacement fiable et sûr. La conception de ce système a été abordée selon trois axes. L'utilisation de la synthèse binaurale pour générer des sons 3D est limitée par le problème de l'individualisation des HRTF. Une méthode a été mise en place pour adapter les individus aux HRTF en utilisant la plasticité du cerveau. Évaluée avec une expérience de localisation, cette méthode a permis de montrer les possibilités d'acquisition rapide d'une carte audio-spatiale virtuelle sans utiliser la vision. La sonification de données spatiales a été étudiée dans le cadre d'un système permettant la préhension d'objet dans l'espace péripersonnel. Les capacités de localisation de sources sonores réelles et virtuelles ont été étudiées avec un test de localisation. Une technique de sonification de la distance a été développée. Consistant à relier le paramètre à sonifier aux paramètres d'un effet audio, cette technique peut être appliquée à tout type de son sans nécessiter d'apprentissage supplémentaire. Une stratégie de sonification permettant de prendre en compte les préférences des utilisateurs a été mise en place. Les " morphocons " sont des icônes sonores définis par des motifs de paramètres acoustiques. Cette méthode permet la construction d'un vocabulaire sonore indépendant du son utilisé. Un test de catégorisation a montré que les sujets sont capables de reconnaître des icônes sonores sur la base d'une description morphologique indépendamment du type de son utilisé.

Penser les traitements du son spatialisés en ambisonie permet de mettre en valeur le potentiel musical de la décomposition du champ sonore en harmoniques sphériques, et amène à redéfinir la représentation de l’espace sonore. Cette thèse défend que les représentations abstraites et intermédiaires de l’espace sonore permettent d’élaborer de nouvelles approches originales de la mise en espace du son. Le raisonnement amenant à cette affirmation commence par l’appropriation musicale de l’approche ambisonique. La création de nouveaux traitements de l’espace et du son amène à utiliser de manière originale les signaux associés aux harmoniques sphériques, et à concevoir différemment les relations qui les régissent, ainsi que leur hiérarchisation. La particularité de ces approches expérimentales et les caractéristiques singulières des champs sonores générés, nécessitent de concevoir de nouveaux outils théoriques et pratiques pour leur analyse et leur restitution. Les changements opérés permettent alors de libérer cette approche des enjeux techniques et matériels initiaux en ambisonie. Mais ils permettent surtout de s’émanciper des modèles psychoacoustiques et acoustiques sur lesquels ces techniques reposent originellement. Dans ce contexte, les signaux associés aux harmoniques sphériques ne sont plus nécessairement une représentation rationnelle du champ sonore, mais deviennent une représentation abstraite de l’espace sonore possédant en soi, un potentiel musical. Cette thèse propose alors un nouveau modèle de spatialisation fondé sur une décomposition matricielle de l’espace sonore permettant de valider les hypothèses
The creation of sound effects in space with Ambisonics highlights the musical potential of sound field decomposition by spherical harmonics, and redefines the representation of the sound space. This thesis defends that the abstract and intermediate representations of the sound space make it possible to develop new original approaches to sound spatialization. The reasoning that leads to this affirmation begins with the musical appropriation of the ambisonic approach. The creation of new space and sound processing patterns in Ambisonics leads to an original way of using signals associated with spherical harmonics, and to a different conception of the relations between them, and their hierarchization. The specificities of these experimental approaches and the singular characteristics of the sound fields generated call for the design of new theoretical and practical tools, for their analysis and restitution. The performed changes make it possible to free this approach from the initial technical and material issues of Ambisonics. But above all, it emancipates this approach from the psychoacoustic and acoustic models on which ambisonic techniques are originally defined. In this context, the signals associated with spherical harmonics are no longer necessarily a rational representation of the sound field but become an abstract representation of the sound space possessing in itself a musical potential. To validate the hypotheses, this thesis then proposes a new spatialization model based on a matrix decomposition of the sound space

This thesis covers the area of soundfield representation, reconstruction and perception. The complexity and information content of a soundfield presents many mathematical and engineering challenges for accurate reconstruction. After an in-depth review of the field of mathematical soundfield representation, an analysis of the numerical and practical constraints for soundfield reconstruction is presented. A review of work in experimental psycho-acoustics higlights the variability of spatial sound perception. It is shown that the error and uncertainty in perception is of a comparable magnitude to the accuracy achievable by present soundfield systems. Therefore, the effects of hearing adaption, sensory bias, sensory conflict, and contextual memory cannot be ignored. If the listening environment is inappropriate or in conflict with the desired perceptual experience, little is gained from more complex soundfield representation or reconstruction. The imp! lications of this result to the delivery of spatial audio is discussed and some open problems for further exploration and experimentation are detailed.

It is not uncommon to read claims of music’s ability to affect our sense of time and its rate of passage. Indeed, such effects are often considered among the most distinctive and prized aspects of musical aesthetics. Yet when it comes to the similarly abstract notion of space and its manipulation by musical structures, theorists are generally silent. My dissertation addresses this gap in the literature and shows how music’s spatial effects arise through an affective engagement with musical works. In this study, I examine an eclectic selection of compositions to determine how the spaces we inhabit are transformed by the music we hear within them. Drawing on Maurice Merleau-Ponty’s theory of embodied perception, as well as research on acoustics, sound studies, and media theory, I deploy an affective model of spatial perception—a model that links the sense of space with the moment-to-moment needs and desires of the perceiver— to explain how these musical modulations of space occur. My claim is that the manner in which the music solicits our engagement affects how we respond, which in turn affects what we perceive. I begin by discussing the development of recording technology and how fixed media works deemed “spatial music” reinforce a particular conception of space as an empty container in which sound sources are arrayed in specific locations relative to a fixed listening position. After showing how innovative studio techniques have been used to unsettle this conventional spatial configuration, I then discuss examples of Renaissance vocal music, instrumental chamber music, and 20th century electronic music in order to develop a richer understanding of the range of spatial interactions that musical textures and timbres can provide. In my final chapter, I draw upon these varieties of affective engagement to construct a hermeneutic analysis of the spatial experience afforded by Steve Reich’s Electric Counterpoint, thereby modeling a phenomenological method for grounding interpretation in embodied, rather than strictly discursive, practices. By soliciting movement through the call for bodily action, music allows us an opportunity to fit together one world of possibilities with another, thereby providing an occasion for grasping new meanings presented through the work. The spatial aspect of music, therefore, does not consist in merely recognizing an environmental setting populated by individual sound sources. Through the embodied practices of music perception and the malleability of space they reveal, we are afforded an opportunity to reshape our understanding of the world around us.

[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.
[CAT] 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 no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/142696
TESIS

O espaço, o tempo e o som, são paradigmas inerentes à condição humana. A paisagem sonora que nos rodeia chega até nós de todos os lados, e o cérebro tem a capacidade, juntamente com fenómenos físicos, de perceber exatamente de onde vem determinado som, mesmo não estando em contato visual com a fonte sonora. Sendo tão natural ao Homem esta noção de “espaço sonoro”, era também natural a aplicação da espacialização sonora nas expressões artísticas onde o som é fundamental. A música seria a primeira expressão artística onde, conscientemente, se pensaria uma peça que oferecesse ao espetador uma sensação de espaço distinta do habitual concerto. No cinema, o primeiro filme onde é usada a espacialização sonora, mais frequentemente denominado surround, foi no “Fantasia” de Walt Disney (1941). A orquestra, responsável por sonorizar o filme foi dividida em quatro secções, e captada em quatro pistas independentes, que foram posteriormente reproduzidas em quatro altifalantes distintos. Na música, a espacialização é um assunto debatido desde muito cedo. Já em 1600 Giovanni Gabrieli, músico veneziano e organista principal da basílica de S. Marcos, dispôs vários instrumentistas por vários pontos da basílica, interpretando composições musicais da sua própria autoria, que criou especialmente para serem tocadas na basílica. Isto representa o conceito base de espacialização e mostra que, como referido anteriormente, desde cedo músicos e compositores se debatem com este tema. Pierre Boulez, por exemplo, compôs “Répons”. Esta é uma peça importantíssima no estudo da espacialização, onde o objecto central é uma orquestra, e à sua volta encontra-se a audiência. Espalhados por seis pontos distintos encontram-se diferentes instrumentistas solistas que, captados por microfones, são processados em tempo real e reproduzidos em diferentes espaços da sala. Esta peça “obrigou” ao desenvolvimento de software e hardware específico para a sua concretização. A espacialização da banda sonora de “Bom Dia, Alegria!” resulta do estudo da relação entre a perceção auditiva, o espaço acústico e a arte musical, dando assim origem à presente dissertação.
Space, time and sound are paradigm connected to human condiction. Soundscape that around us, arrives all over the place, and the brain has capacity with physical phenomenal to realize exactly where comes an particular sound, even if not in visual contact with the sound source. Being so natural to man this notion of "sound space" was also the application of natural spatial sound in artistic expression where the sound is critical. The music would be the first artistic expression which consciously one would think a piece that offers the spectator a distinct feeling from the usual concert space. In Cinema, the first film where the sound spatialization was used more often called surround, was in "Fantasia " Walt Disney (1941). ! The orchestra responsible to make the sound to the film was divided into four sections, and captured four independent tracks, which were later reproduced in four different speakers. In music, the spatial distribution is a subject debated since long ago. Already in year of 1600 Giovanni Gabrieli, Venetian musician and principal organist of St. Mark's Basilica, arranged several musicians for several points of the basilica, playing musical compositions of his own composition, which created especially to be played in the basilica. This is the basic concept of spatial and shows that, as mentioned above, early musicians and composers are struggling with this issue. Boulez, for example, composed "Répons". This is a very important part in the study of spatialization, where the central object is an orchestra, and around it is the audience. Spread across six distinct points are different instrumentalists soloists who, captured by microphones are processed in real time and played in different room spaces. This piece "forced" to software development and specific hardware to achieve them. The spatialization of the "Bom dia, Alegria!" soundtrack, results of the study of the relationship between auditory perception, the acoustic space and the art of music, thus giving rise to this dissertation.