Spherical harmonic decomposition of a sound field based on observations along the equator of a rigid spherical scatterer
Journal article, 2021

We present a method for computing a spherical harmonic representation of a sound field based on observations of the sound pressure along the equator of a rigid spherical scatterer. Our proposed solution assumes that the captured sound field is height invariant so that it can be represented by a two-dimensional (2D) plane wave decomposition (PWD). The 2D PWD is embedded in a three-dimensional representation of the sound field, which allows for perfectly undoing the effect of the spherical scattering object. If the assumption of height invariance is fulfilled, then the proposed solution is at least as accurate as a conventional spherical microphone array of the same spherical harmonic order, which requires a multiple of the number of sensors. Our targeted application is binaural rendering of the captured sound field. We demonstrate by analyzing the binaural output signals that violations of the assumptions that the solution is based on—particularly height invariance and consequently also horizontal propagation—lead to errors of moderate magnitude.

Author

Jens Ahrens

Chalmers, Architecture and Civil Engineering, Applied Acoustics

Hannes Helmholz

Chalmers, Architecture and Civil Engineering, Applied Acoustics

David Lou Alon

Facebook Reality Labs

Sebastia V. Amengual Gari

Facebook Reality Labs

Journal of the Acoustical Society of America

0001-4966 (ISSN) 1520-8524 (eISSN)

Vol. 150 2 805-815

Binaural Rendering of Spherical Microphone Array Data

Oculus Inc., 2018-05-01 -- 2019-04-30.

Subject Categories

Media and Communication Technology

Communication Systems

Signal Processing

Areas of Advance

Information and Communication Technology

DOI

10.1121/10.0005754

More information

Latest update

8/24/2021