Multiple source localisation in the spherical harmonic domain

Spherical arrays facilitate processing and analysis of sound fields with the potential for high resolution in three dimensions in the spherical harmonic domain. Using the captured sound field, robust source localisation systems are required for speech acquisition, speaker tracking and environment mapping. Source localisation becomes a challenging problem in reverberant environments and under noisy conditions, leading to potentially poor performance in cocktail party scenarios. This paper evaluates the performance of a low-complexity localisation approach using spherical harmonics in reverberant environments for multiple speakers. Eigen-beams are used to estimate pseudo-intensity vectors pointing in the direction of sound intensity. This paper proposes a clustering approach in which the intensity vectors of active sound sources and strong reflections are extracted, yielding an estimate of the source direction in azimuth and inclination as an approach to source localisation.