Analysis and Design of Multichannel Systems for Perceptual Sound Field Reconstruction

Abstract

Abstract-This paper presents a systematic framework for the analysis and design of circular multichannel surround sound systems. Objective analysis based on the concept of active intensity fields shows that for stable rendition of monochromatic plane waves it is beneficial to render each such wave by no more than two channels. Based on that finding, we propose a methodology for the design of circular microphone arrays, in the same configuration as the corresponding loudspeaker system, which aims to capture inter-channel time and intensity differences that ensure accurate rendition of the auditory perspective. The methodology is applicable to regular and irregular microphone/speaker layouts, and a wide range of microphone array radii, including the special case of coincident arrays which corresponds to intensity-based systems. Several design examples, involving first and higher-order microphones are presented. Results of formal listening tests suggest that the proposed design methodology achieves a performance comparable to prior art in the center of the loudspeaker array and a more graceful degradation away from the center.Index Terms-Active intensity, microphone array, microphone directivity, multichannel audio, spatial hearing, surround sound recording, tangent panning law, time-intensity trading.

Perceptual Spatial Audio Recording, Simulation, and Rendering: An overview of spatial-audio techniques based on psychoacoustics

“…Another often cited reason to avoid using ICTDs is the difficulty of controlling the direction of a virtual source by means of time delays. This view has been recently challenged [30], as it will be discussed in Section IV-C.…”

“…Perceptual Sound Field Reconstruction (PSR) [30], [54] is a recently developed flexible multichannel recording, reproduction and synthesis technology. Similarly to DirAC it provides a systematic framework for recording and reproduction of sound scenes.…”

“…The five channel PSR system design based on intensity and time-intensity principles, as specified above, was subjectively evaluated and compared with 2nd-order Ambisonics in terms of subjective localization accuracy [30]. Fig.…”

Localization Experiments with Reporting by Head Orientation: Statistical Framework and Case Study

“…A large variety of characteristics have been studied, ranging from the just-noticeable-differences in localization accuracy, adaptation, and learning effects, to the influence of the source's spectral content and room reflections [1][2][3]. Recent experiments also studied the contribution of high frequency content in the presence of a noise masker [4], the degradation of localization accuracy with outer ears occlusions [5] and bilateral hearing aids [6], and the localization of multiple coherent sound sources [7].…”

“…Subjects are typically asked to indicate the direction of the perceived sound source by (a) reporting the closest loud-speaker, fixed acoustic pointer or label [7,4,2]; (b) steering a movable pointer [8]; (c) reporting the direction on a graphical user interface (GUI) or on paper [6]; or (d) turning their face toward the perceived sound source after the stimulus has been presented [9,5]. This paper is concerned with experiments where subjects report the position of the perceived sound source by turning toward it while the stimulus is being presented.…”