Convention Paper
Physical Properties of Modal Beamforming in the Context of Data-Based Sound Reproduction
AES Convention 139 · Paper 9468 · October 2015
Abstract
A sound field captured by a microphone array can be decomposed into plane waves, and auralized by means of sound field synthesis or binaural synthesis. The achievable performance is limited by the spatial resolution of the plane wave decomposition. Typically, the plane wave decomposition is performed with respect to an expansion center. If the expansion center is translated, the accuracy of the plane wave representation decreases. It is thus likely that the reproduced sound field also suffers form artifacts at off-center listening positions. The aim of this paper is to investigate the physical properties of a sound field represented as plane wave decomposition. The sound field is re-expanded with respect to different positions, and the corresponding modal spectra are investigated. This analysis successfully explains the spectral and temporal properties of spatially continuous and discrete modal beamforming.
