Author :
Publisher :
Page : pages
File Size : 17,83 MB
Release : 2004
Category :
ISBN :
Three-dimensional (3D) sound is a significant component of virtual reality. 3D sound systems or directional sound systems are designed to animate the sound space produced by real sound sources. In this thesis, basic concepts of 3D sound are introduced. The Head Related Transfer Functions (HRTFs) are analyzed in both the time and frequency domain. A 3D sound system is implemented using practical, measured HRTF data.
Author : Bosun Xie
Publisher : J. Ross Publishing
Page : 505 pages
File Size : 46,5 MB
Release : 2013-07-23
Category : Technology & Engineering
ISBN : 1604270705
This book systematically details the basic principles and applications of head-related transfer function (HRTF) and virtual auditory display (VAD), and reviews the latest developments in the field, especially those from the author’s own state-of-the-art research group. Head-Related Transfer Function and Virtual Auditory Display covers binaural hearing and the basic principles, experimental measurements, computation, physical characteristics analyses, filter design, and customization of HRTFs. It also details the principles and applications of VADs, including headphone and loudspeaker-based binaural reproduction, virtual reproduction of stereophonic and multi-channel surround sound, binaural room simulation, rendering systems for dynamic and real-time virtual auditory environments, psychoacoustic evaluation and validation of VADs, and a variety of applications of VADs. This guide provides all the necessary knowledge and latest results for researchers, graduate students, and engineers who work in the field of HRTF and VAD.
Author : William G. Gardner
Publisher : Springer Science & Business Media
Page : 176 pages
File Size : 13,56 MB
Release : 1998-04-30
Category : Technology & Engineering
ISBN : 9780792381563
3-D Audio Using Loudspeakers is concerned with 3-D audio systems implemented using a pair of conventional loudspeakers. A well-known problem with these systems is the requirement that the listener be properly positioned for the 3-D illusion to function correctly. This book proposes using the tracked position of the listener's head to optimize the acoustical presentation, thus producing a much more realistic illusion over a larger listening area than existing loudspeaker 3-D audio systems. Head-tracking can be accomplished by applying pattern recognition techniques to images obtained from a video camera. Thus, an immersive audio environment can be created without donning headphones or other equipment. 3-D Audio Using Loudspeakers discusses the theory, implementation, and testing of a head-tracked loudspeaker 3-D audio system. Crosstalk cancellers that can be steered to the location of a tracked listener are described. The objective performance of these systems has been evaluated using simulations and acoustical measurements made at the ears of human subjects. Many sound localization experiments were also conducted; the results show that head-tracking both significantly improves localization when the listener is displaced from the ideal listening location, and also enables dynamic localization cues. Much of the theory and experimental results presented are also applicable to loudspeaker 3-D audio systems in general, not just head-tracked ones. 3-D Audio Using Loudspeakers is of interest to researchers studying virtual acoustic displays, and to engineers developing the same. The book serves as a valuable reference to anyone working in this field.
Author : Kazuhiro Iida
Publisher : Springer Nature
Page : 234 pages
File Size : 49,47 MB
Release : 2019-10-23
Category : Medical
ISBN : 9811397457
This book covers all aspects of head-related transfer function (HRTF), from the fundamentals through to the latest applications, such as 3D sound systems. An introductory chapter defines HRTF, describes the coordinate system used in the book, and presents the most recent research achievements in the field. HRTF and sound localization in the horizontal and median planes are then explained, followed by discussion of individual differences in HRTF, solutions to this individuality (personalization of HRTF), and methods of sound image control for an arbitrary 3D direction, encompassing both classic theory and state of the art data. The relations between HRTF and sound image distance and between HRTF and speech intelligibility are fully explored, and measurement and signal processing methods for HRTF are examined in depth. Here, supplementary material is provided to enable readers to measure and analyze HRTF by themselves. In addition, some typical HRTF databases are compared. The final two chapters are devoted to the principles and applications of acoustic virtual reality. This clearly written book will be ideal for all who wish to learn about HRTF and how to use it in their research.
Author : Erkuden Lopez
Publisher :
Page : 84 pages
File Size : 38,76 MB
Release : 1995
Category :
ISBN :
Author : Durand R. Begault
Publisher :
Page : 248 pages
File Size : 29,84 MB
Release : 2000
Category : Computer sound processing
ISBN :
Author : John Garas
Publisher : Springer Science & Business Media
Page : 201 pages
File Size : 42,18 MB
Release : 2012-12-06
Category : Technology & Engineering
ISBN : 1441987762
Adaptive 3D Sound Systems focuses on creating multiple virtual sound sources in 3D reverberant spaces using adaptive filters. Adaptive algorithms are introduced and explained, including the multiple-error filtered-x algorithm and the adjoint LMS algorithm. The book covers the physical, psychoacoustical, and signal processing aspects of adaptive and non-adaptive 3D sound systems. Included is an introduction to spatial hearing, sound localization and reverberation, frequency selectivity of the human auditory system, the state of the art in HRTF-based 3D sound systems, binaural synthesis, and loudspeaker displays. The adaptive approach to HRTF-based 3D sound systems is examined in detail for the general case of creating multiple virtual sound sources at the ears of multiple listeners in a reverberant 3D space. The derived solution can be applied to other applications, such as cross-talk cancellation, loudspeakers and room equalization, concert hall simulation, and active sound control. Several solutions for the problem of moving listeners are introduced. Strategies for enlarging the zones of equalization around the listeners' ears, correct loudspeakers positioning, and using multiresolution filters are proposed. Fast multiresolution spectral analysis using non-uniform sampling is developed for implementation of multiresolution filters. The well-focused topics, along with implementation details for adaptive algorithms, make Adaptive 3D Sound Systems suitable for multimedia applications programmers, advanced level students, and researchers in audio and signal processing.
Author : Franz Zotter
Publisher : Springer
Page : 210 pages
File Size : 39,32 MB
Release : 2019-04-30
Category : Technology & Engineering
ISBN : 3030172074
This open access book provides a concise explanation of the fundamentals and background of the surround sound recording and playback technology Ambisonics. It equips readers with the psychoacoustical, signal processing, acoustical, and mathematical knowledge needed to understand the inner workings of modern processing utilities, special equipment for recording, manipulation, and reproduction in the higher-order Ambisonic format. The book comes with various practical examples based on free software tools and open scientific data for reproducible research. The book’s introductory section offers a perspective on Ambisonics spanning from the origins of coincident recordings in the 1930s to the Ambisonic concepts of the 1970s, as well as classical ways of applying Ambisonics in first-order coincident sound scene recording and reproduction that have been practiced since the 1980s. As, from time to time, the underlying mathematics become quite involved, but should be comprehensive without sacrificing readability, the book includes an extensive mathematical appendix. The book offers readers a deeper understanding of Ambisonic technologies, and will especially benefit scientists, audio-system and audio-recording engineers. In the advanced sections of the book, fundamentals and modern techniques as higher-order Ambisonic decoding, 3D audio effects, and higher-order recording are explained. Those techniques are shown to be suitable to supply audience areas ranging from studio-sized to hundreds of listeners, or headphone-based playback, regardless whether it is live, interactive, or studio-produced 3D audio material.
Author : Ramona Bomhardt
Publisher : Logos Verlag Berlin GmbH
Page : 162 pages
File Size : 36,80 MB
Release : 2017-09-04
Category : Science
ISBN : 3832545433
Human sound localization helps to pay attention to spatially separated speakers using interaural level and time differences as well as angle-dependent monaural spectral cues. In a monophonic teleconference, for instance, it is much more difficult to distinguish between different speakers due to missing binaural cues. Spatial positioning of the speakers by means of binaural reproduction methods using head-related transfer functions (HRTFs) enhances speech comprehension. These HRTFs are influenced by the torso, head and ear geometry as they describe the propagation path of the sound from a source to the ear canal entrance. Through this geometry-dependency, the HRTF is directional and subject-dependent. To enable a sufficient reproduction, individual HRTFs should be used. However, it is tremendously difficult to measure these HRTFs. For this reason this thesis proposes approaches to adapt the HRTFs applying individual anthropometric dimensions of a user. Since localization at low frequencies is mainly influenced by the interaural time difference, two models to adapt this difference are developed and compared with existing models. Furthermore, two approaches to adapt the spectral cues at higher frequencies are studied, improved and compared. Although the localization performance with individualized HRTFs is slightly worse than with individual HRTFs, it is nevertheless still better than with non-individual HRTFs, taking into account the measurement effort.
Author : Wen Zhang
Publisher :
Page : 332 pages
File Size : 29,80 MB
Release : 2010
Category : Acoustic filters
ISBN :
There has been a growing interest in spatial sound generation arising from the development of new communications and media technologies. Binaural spatial sound systems are capable of encoding and rendering sound sources accurately in three dimensional space using only two recording/playback channels. This is based on the concept of the Head-Related Transfer Function (HRTF), which is a set of acoustic filters from the sound source to a listener's eardrums and contains all the listening cues used by the hearing mechanism for decoding spatial information encoded in binaural signals. The HRTF is usually obtained from acoustic measurements on different persons. In the case of discrete data and sets of measurements corresponding to different human subjects, it is desirable to have a continuous functional representation of the HRTF for efficiently rendering moving sounds in the virtual spatial audio systems; further this representation should be well-suited for customization to an individual listener. In this thesis, modal analysis is applied to examine the HRTF data structure, that is to employ the wave equation solutions to expand the HRTF with separable basis functions. This leads to a general representation of the HRTF into separated spatial and spectral components, where the spatial basis functions modes account for the HRTF spatial variations and the remaining HRTF spectral components provide a new means to examine the human body scattering behavior. The general model is further developed into the HRTF continuous functional representations. We use the normalized spatial modes to link near-field and far-field HRTFs directly, which provides a way to obtain the HRTFs at different ranges from measurements conducted at only a single range. The spatially invariant HRTF spectral components are represented continuously using an orthogonal series. Both spatial and spectral basis functions are well known functions, thus the developed analytical model can be used to easily examine the HRTF data feature-individualization. An important finding of this thesis is that the HRTF decomposition with the spatial basis functions can be well approximated by a finite number, which is defined as the HRTF spatial dimensionality. The dimensionality determines the least number of the HRTF measurements in space. We perform high resolution HRTF measurements on a KEMAR mannequin in a semi-anechoic acoustic chamber. Both signal processing aspects to extract HRTFs from the raw measurements and a practical high resolution spatial sampling scheme have been given in this thesis.
