Binaural technology for e.g. rendering auditory virtual environments (original) (raw)
Related papers
2011
This thesis has been submitted to the Faculty of Engineering, Science and Medicine at Aalborg University in partial fulfillment of the requirements for the award of the Ph.D. degree. The research was carried out at the University's Section of Acoustics in the period from June 2006 to August 2009. I would like to thank all the colleagues at the Section of Acoustics for the inspiring environment. Special thanks to Henrik Møller and Dorte Hammershøi for offering me the PhD position that led to the research presented here. Some of the investigations conducted for this Thesis, and other pilot studies that are not included here, made used of a database of HRTFs, ATFs and HTTFs measurements on human subjects which was available from previous works at the Section of Acoustics. The group of colleagues that conducted those measurements is kindly acknowledged and mentioned where appropriate throughout the Thesis. Claus Vestergaard Skipper is acknowledged for his help with the mechanical work and mounting of the arc of loudspeakers that was used in several of the studies reported here, and Henrik Zimmermann for helping me translating the summary to Danish. Brian Katz and Durand Begault are thanked for their invitation to participate in the round robin of HRTFs measurement systems, which materialized in part of Chapter 2. I would also like to thank my friends in Denmark and in Argentina, who supported me during the process of working towards a Ph.D. Special thanks to my partner Kristian, whose artistic mind helped my development in all aspects of life.
1998
This paper presents the method of binaural synthesis for use in creation of three-dimensional sound images in virtual reality and multimedia applications. Special attention is given to the selection of head-related transfer functions (HRTFs), and how this choice affects the further processing. A brief introduction to spatial hearing is gi ven, followed by a division of the sound transmission to the eardrum. The selection of HRTFs for binaural synthesis is discussed. It is then desc ribed how the binaural synthesis is carried o ut using information on sound transmission in the room as input. Examples of headphone characteristics are given, and it is described how the correct eardrum signals are obtained by headphone reproduction.
The Influence of Nonindividual Hrtf in Binaural Reproduction Using Headphones
2012
A 3D virtual surround sound environment can be created for a listener using headphone reproduction. For this purpose, a set of head related transfer functions are needed. These functions are convolved with audio signals of a sound source resulting in a 3D virtual spatialization of the source. Two of the most common problems in headphone reproduction are in-head-localization and front-back confusion. In the present paper we are concentrating on analysing the influence of a personal or not personal Hrtf use. For this task it has been measured and built a database with individual Hrtfs for more than one person and performed subjective audio listening tests. In these listening tests we have been evaluated the perfomance of the reduction of reversal confusion in localization when different nonindividual Hrtf in as compared to using individual Hrtf for different types of audio signals.
The Journal of the Acoustical Society of America, 2013
A virtual auditory space can be presented to a listener based on binaural synthesis using head-related transfer functions (HRTFs) that are obtainable by measurements or numerical simulations. Due to hardware complexity, HRTF measurements are typically made for a fixed source distance though they are used in binaural synthesis for variable source distances. However, it is known that HRTFs depend on source distance especially for proximal sources for distance less than 1 m. So it is possible that binaural synthesis with HRTFs for a fixed source distance may result in degradations for proximal sound image perception. In this paper, experiments were performed to examine how the use of distantvariant or -invariant HRTFs affect the perception of a proximal sound source in a virtual auditory space in which the listener's motion is compensated by head tracking. HRTFs for source distances up to 1 m, in 5 cm steps, are numerically simulated using the boundary element method. Results show the difference between presented and perceived source distances being significantly smaller when distance-variant HRTFs were used. This indicates that the use of HRTFs corresponding to actual sound source position leads to accurate perception of a proximal source.
2014
Laboratory studies of virtual auditory display (VAD) systems have dominated the evaluation of individually customized binaural technology, that is, an evaluation to reveal whether an application is working for individual listeners when care has been taken to make the system work for each of them as best as possible. The studies reviewed in this paper attempted to move away from strict laboratory studies to investigate more complex auditory localization tasks, and to attempt to iteratively improve VAD system performance for human subjects showing significant differences in the customized deployment of binaural technology for headphone reproduction. Differences between subjects typically exist both in physical and perceptual responses to incident sound, the most obvious difference being in the observed pattern of spectral variation in their individually-measured Head-Related Transfer Functions (HRTFs). More important for the VAD application under investigation, however, are the observ...
Trends in Acquisition of Individual Head-Related Transfer Functions
The Technology of Binaural Listening, 2013
Head-related transfer functions, HRTFs, that is, the pair of acoustic transfer functions from a sound source in anechoic space to the human ears, are important elements of binaural technology. In order to make practical use of them, fast and comfortable means for the aquisition of individual HRTFs are required and, furthermore, convenient data formats for their comprehensive representation are needed. This chapter first recapitulates early and seminal work in the field of HRTFs. From here, a concise picture of recent trends for spatially discrete and continuous measurement of HRTFs, with a focus on the more recent continuous, that is, dynamic approach, is developed. For the continuous method, latest results regarding the optimization of the loudspeaker excitation signal for the measurement are presented. With respect to HRTF representation and usage, the chapter refers to spatially-discrete databases in time-or frequency-domain and, additionally, to the spatial Fourier-series domain. The latter constitutes an ideal basis for both interpolation and extrapolation of discrete data as well as for the representation of the results of spherically-continuous measurements. 3 Both the data and the project documentation are available from the European Acoustics Association, EAA 4
2017 IEEE 3rd VR Workshop on Sonic Interactions for Virtual Environments (SIVE)
Sound in Virtual Reality (VR) has been explored in a variety of algorithms which try to enhance the illusion of presence, improving sound localization and spatialization in the virtual environment. As new systems are developed, different models are applied. There is still the need to evaluate and understand the main advantages of each of these approaches. In this study, a performance comparison of two methods for real-time 3D binaural sound tested preferences and quality of presence for headphones in a VR experience. Both the mathematical based HRTF and the convolution based measured HRTF from the MIT KEMAR show a general similarity in the participants sense of localization, depth and presence. Nevertheless, the tests also indicate a preference in elevation perception for the convolution-based measured HRTF. Further experiments with new tools, techniques, contexts, and guidelines are therefore required to highlight the importance and differences between these two methods and other implementations.
Acoustical Science and Technology, 2003
This paper reviews development of spatial auditory display technology based upon 20 years of research evaluating digital filters designed to spatially position auditory images associated with sound sources presented via earphones. The motivation for this review was to attempt to provide clarification regarding some of the issues and assumptions that underlie such research-driven binaural technology development. After a general discussion of research goals and methods, instructive research results are presented to underscore the main points, especially with regard to questions that could serve to stimulate further useful work on directional filter design. These include questions of how best to customize filters for individual users, and, conversely, how to optimize filters for general use. Also considered are the related questions of how best to evaluate the performance of generic Head-Related Transfer Functions (HRTFs), in contrast to those that are measured for the use of a specific individual. At the heart of this review is a focus on the methods that are most appropriate for the evaluation of auditory imagery resulting from synthetic sound spatialization. While a primary goal for binaural synthesis is to spatially position an auditory image, methods typically employed to study the ability of human listeners to spatially localize an actual sound source address only a narrow subset of the issues that are important to the development of adequate spatial auditory display technology.