Reconstruction of sound fields with a spherical microphone array

Spherical microphone arrays are very well suited for sound field measurements in enclosures or interior spaces, and generally in acoustic environments where sound waves impinge on the array from multiple directions. Because of their directional properties, they make it possible to resolve sound waves traveling in any direction. In particular, rigid sphere microphone arrays are robust, and have the favorable property that the scattering introduced by the array can be compensated for-making the array virtually transparent. This study examines a recently proposed sound field reconstruction method based on a point source expansion, ie equivalent source method, using a rigid spherical array. The study examines the capability of the method to distinguish between sound waves arriving from different directions (ie, as a sound field separation method). This is representative of the potential of the method to perform sound field identification and visualization in non-anechoic spaces, and ultimately for general in-situ measurements