Spatial sound rendering has many applications such as music production, movies, electronic gaming and teleconferencing. Each of the applications may have different quality and complexity ...requirements. This paper presents a new spatial sound rendering framework that aims at producing realistic multichannel audio while being flexible and scalable so that is can be extended and adopted by various applications. The proposed framework uses multi-channel measured room impulse response (MMRIR) as the basis for building a room acoustic model which is used to synthesize multi-channel audio. The proposed framework has been evaluated by informal listening tests
Linux screen reader Parente, Peter; Clippingdale, Brett
ACM SIGACCESS Conference on Assistive Technologies: Proceedings of the 8th international ACM SIGACCESS conference on Computers and accessibility; 23-25 Oct. 2006,
10/2006
Conference Proceeding
The Linux Screen Reader (LSR) project is an open source effort to develop an extensible assistive technology for the GNOME desktop environment. The goal of the project is to create a reusable ...development platform for building alternative and supplemental user interfaces in support of people with diverse disabilities. In this paper, we highlight some key features of LSR including cascading scripts that tailor the user experience to particular applications and tasks, support for novel methods of input and output (e.g. concurrent spatial audio) suited to the needs and preferences of the user, and the ease and flexibility of extension development.
Generating spatial sound and playing it through headphones is a demanding task, since two important factors, ILD - inter-aural level difference and ITD - inter-aural time difference, need to be taken ...into consideration. The problem can be solved by the use of head related transfer functions (HRTF) which represent a set of empirically measured functions, one for each spatial direction. The complete reconstruction of HRTF is possible through the use of finite impulse response (FIR) filters with 512 coefficients each. Since the spectrum of HRTF consists of distinctive maximums and minimums, the spectrum could be approximated by the use of resonators and notch filters. The approximation of the complete spectrum (20 Hz - 20 kHz) could be done by the use of six resonators and one notch filter. Our approach to spatial sound generation using HRTF created by the use of recursive (IIR) filters presents a practical and computationally effective solution. It also indicates a way to uniformly model all factors connected to spatial sound perception.
Ambisonics is a series of spatial sound reproduction system based on spatial harmonics decomposition and each order approximation of sound field. Ambisonics signals are originally intended for ...loudspeakers reproduction. By using head-related transfer functions (HRTFs) filters, binaural Ambisonics converts the Ambisonics signals for static or dynamic headphone reproduction. In present work, the performances of static and dynamic binaural Ambisonics reproduction are evaluated and compared. The mean binaural pressure errors across target source directions are first analyzed. Then a virtual source localization experiment is conducted, and the localization performances are evaluated by analyzing the percentages of front-back and up-down confusion, the mean angle error and discreteness in the localization results. The results indicate that binaural Ambsonics reproduction with insufficiently high order (for example, 5-10 order) is unable to recreate correct high-frequency magnitude spectra in binaural pressures, resulting in degradation in localization for static reproduction. Because dynamic localization cue is included, dynamic binaural Ambisoncis reproduction yields obviously better localization performance than static reproduction with the same order. Even a 3-order dynamic binaural Ambisoncis reproduction exhibits appropriate localizations performance.
Provider: - Institution: - Data provided by Europeana Collections- Title: Binaural dummy heads measurements and sound spatialization Binaural sound is the one that is played through headphones and ...provides the sensation of being immersed in the environment where the sound was recorded, creating a spatial sound illusion to the listener. This type of sound is being widely used in the virtual reality field, mostly in videogames, where knowing the sound source¿s position gives advantages to the user. In this study, the procedure and results of the analysis and measurement of two acoustic dummy heads in a non-anechoic chamber are exposed. In order to do it, binaural impulse responses (BIR) of the dummy heads have been measured from multiple 3D positions around them, covering almost the entire surface of a sphere. In addition, speakers with customized features have been built to make these measurements. The most relevant application of this study is the possibility to create a new binaural sound just by using the BIR measurements, giving the immersed sensation to the listener and achieving sound¿s binauralization.- Título del TFG: Medidas de maniquís acústicos binaurales y espacialización de sonidos El sonido binaural es aquel que se reproduce mediante auriculares y que proporciona la sensación de estar inmerso en el entorno en el que fue grabado, creando una ¿ilusión¿ sonora espacial al oyente. Este tipo de sonido se está empleando cada vez más en el mundo de la realidad virtual, sobre todo en videojuegos, donde experimentar la posición de una fuente de sonido aporta grandes ventajas. En este trabajo se expone el procedimiento y los resultados del análisis y medida de dos maniquís acústicos (también denominados cabezas binaurales) en una cámara no anecoica. Para ello se han medido las respuestas al impulso binaurales (binaural impulse response, BIR) de los maniquís desde múltiples posiciones en 3D alrededor del mismo, hasta completar casi una esfera. Así mismo, se han construido altavoces especiales ex profeso que reunieran las características deseadas para esta tarea. La aplicación más relevante de este trabajo reside en la posibilidad de auralizar cualquier sonido con las respuestas binaurales medidas, proporcionando la sensación de inmersión al oyente y logrando la binauralización del sonido.- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
Provider: - Institution: - Data provided by Europeana Collections- La creciente popularidad de los sistemas y aplicaciones de realidad virtual, así como las videoconferencias y los videojuegos, ...exigen grandes esfuerzos en la virtualización de audio en tiempo real, contribuyendo poderosamente al sentido de inmersión del usuario. El posicionamiento del sonido se logra mediante la convolución de las fuentes de audio con las colecciones de Head Related Impulse Responses, cuya medición puede ser tediosa y costosa. La interpolación brinda la oportunidad de ahorrar tiempo y esfuerzo al permitirnos obtener muestras fielmente nuevas de unas pocas. El objetivo de esta tesis es diseñar e implementar algoritmos de interpolación para HRIR y Binaural Room Impulse Responses.- Increasing popularity of virtual reality systems and applications, such as videoconferencing and gaming, is demanding vast efforts in real-time audio virtualization, contributing powerfully to the user s sense of immersion. Sound positioning is achieved by means of convolving audio sources with Head Related Impulse Responses collections, whose measurement can be tedious and costly. Interpolation gives the opportunity to save time and efforts by allowing us to obtain faithfully new samples from few ones. The aim of this thesis is to design and implement interpolation algorithms for HRIRs and Binaural Room Impulse Responses.- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
Provider: - Institution: - Data provided by Europeana Collections- ES La Separacón de Fuentes ha sido un tema de intensa investigación en muchas aplicaciones de tratamiento de señaal, cubriendo desde ...el procesado de voz al análisis de im'agenes biomédicas. Aplicando estas técnicas a los sistemas de reproducci'on espacial de audio, se puede solucionar una limitaci ón importante en la resíntesis de escenas sonoras 3D: la necesidad de disponer de las se ñales individuales correspondientes a cada fuente. El sistema Wave-field Synthesis (WFS) puede sintetizar un campo acústico mediante arrays de altavoces, posicionando varias fuentes en el espacio. Sin embargo, conseguir las señales de cada fuente de forma independiente es normalmente un problema. En este trabajo se propone la utilización de distintas técnicas de separaci'on de fuentes sonoras para obtener distintas pistas a partir de grabaciones mono o estéreo. Varios métodos de separación han sido implementados y comprobados, siendo uno de ellos desarrollado por el autor. Aunque los algoritmos existentes están lejos de conseguir una alta calidad, se han realizado tests subjetivos que demuestran cómo no es necesario obtener una separación óptima para conseguir resultados aceptables en la reproducción de escenas 3D- EN Source Separation has been a subject of intense research in many signal processing applications, ranging from speech processing to medical image analysis. Applied to spatial audio systems, it can be used to overcome one fundamental limitation in 3D scene resynthesis: the need of having the independent signals for each source available. Wave-field Synthesis is a spatial sound reproduction system that can synthesize an acoustic field by means of loudspeaker arrays and it is also capable of positioning several sources in space. However, the individual signals corresponding to these sources must be available and this is often a difficult problem. In this work, we propose to use Sound Source Separation techniques in order to obtain different tracks from stereo and mono mixtures. Some separation methods have been implemented and tested, having been one of them developed by the author. Although existing algorithms are far from getting hi-fi quality, subjective tests show how it is not necessary an optimum separation for getting acceptable results in 3D scene reproduction- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
Provider: - Institution: - Data provided by Europeana Collections- Spat~ is a real-time spatial processing software which runs on the Ircam Music Workstation in
the Max graphical signal processing ...environment. It provides a library of elementary modules
(pan-pots, equalizers, reverberators...) linkable into a compact processor integrating the
localization of sound events together with the manipulation of room acoustical quality. This
processor can be configured for various reproduction formats over loudspeaker or
headphones, and controlled through a higher-level user interface including perceptual
attributes derived from psychoacoustical research. Applications include studio recording and
computer music, virtual reality or variable acoustics in rooms.- Contribution au colloque ou congrès : CIARM: International Conference on Acoustics and Musical Research- Version numérique intégrale de l'article- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
Nowadays, visual analytics is mainly performed by programming approaches and viewing the results on a desktop monitor. However, due to the capabilities of smart glasses, new user interactions and ...representation possibilities become possible. This refers especially to 3D visualizations in the medical field, as well as, the industry domain, as valuable depth information can be related to the complex real-world structures and related data, which is also denoted as immersive analytics. However, the applicability of immersive analytics and its drawbacks, especially in the context of mixed reality, are quite unexplored. In order to validate the feasibility of immersive analytics for the aforementioned purposes, we designed and conducted a usability study with 60 participants. More specifically, we evaluated the effects of spatial sounds, performance changes from one analytics task to another, expert status, and compared an immersive analytics approach (i.e., a mixed-reality application) with a desktop-based solution. Participants had to solve several data analytics tasks (outlier's detection and cluster recognition) with the developed mixed-reality application. Thereby, the performance measures regarding time, errors, and movement patterns were evaluated. The separation into groups (low performer vs. high performer) was performed using a mental rotation pretest. When solving analytic tasks in mixed reality, participants changed their movement patterns in the mixed reality setting significantly, while the use of spatial sounds reduced the handling time significantly, but did not affect the movement patterns. Furthermore, the usage of mixed reality for cluster recognition is significantly faster than the desktop-based solution (i.e., a 2D approach). Moreover, the results obtained with self-developed questionnaires indicate 1) that wearing smart glasses are perceived as a potential stressor and 2) that the utilization of sounds is perceived very differently by the participants. Altogether, industry and researchers should consider immersive analytics as a suitable alternative compared to the traditional approaches.
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