Plane-Wave Decomposition of Acoustical Scenes Via Spherical and Cylindrical Microphone Arrays

Abstract

Spherical and cylindrical microphone arrays offer a number of attractive properties such as direction-independent acoustic behavior and ability to reconstruct the sound field in the vicinity of the array. Beamforming and scene analysis for such arrays is typically done using sound field representation in terms of orthogonal basis functions (spherical/cylindrical harmonics). In this paper, an alternative sound field representation in terms of plane waves is described, and a method for estimating it directly from measurements at microphones is proposed. It is shown that representing a field as a collection of plane waves arriving from various directions simplifies source localization, beamforming, and spatial audio playback. A comparison of the new method with the well-known spherical harmonics based beamforming algorithm is done, and it is shown that both algorithms can be expressed in the same framework but with weights computed differently. It is also shown that the proposed method can be extended to cylindrical arrays. A number of features important for the design and operation of spherical microphone arrays in real applications are revealed. Results indicate that it is possible to reconstruct the sound scene up to order p with p 2 microphones spherical array. Index TermsEDICS Categories: AUD-SMCA, AUD-LMAP.

Wave-based sound propagation for VR applications

“…Integrating HRTFs into wavebased techniques involves computation of propagation directions using plane wave decomposition. Prior plane-wave decomposition techniques either use spherical convolution [24] or solve a linear system [39], and are computationally expensive. Interactive wave-based techniques resort to simpler listener directivity models based on a spherical head and a cardioid function [26].…”

“…a rotating siren or a person covering his/her mouth. Additionally, integrating listener directivity into wave-based techniques requires a plane-wave decomposition of the sound field [39]. Previous techniques for performing plane-wave decomposition [23,24,39] are computationally expensive and limited to offline applications.…”

“…Additionally, integrating listener directivity into wave-based techniques requires a plane-wave decomposition of the sound field [39]. Previous techniques for performing plane-wave decomposition [23,24,39] are computationally expensive and limited to offline applications. Recently, physically-based methods have been proposed for sound radiation from directional sources such as fluids [38] and thin shells [5].…”

Spherical array processing with binaural sound reproduction for improved speech intelligibility

“…It can be seen from Fig. 1 however, that a preliminary step of plane wave decomposition (PWD) is required in order to estimate the plane-wave amplitude density function [17][18][19].…”

Capturing and Recreating Auditory Virtual Reality

“…Another method of decomposition 16 is to note that a relationship inverse to the desired one can be established as Ψ = F Λ, where F is a L q × L j matrix with elements f (k;ś q , s j ) equal to the potential caused at microphone at s q by the wave arriving from the direction s j . The equation for f (k;ś q , s j ) is…”