Locating an Acoustic Source Using a Mutual Information Beamformer

Beamforming remains one of the most common methods for estimating the Direction Of Arrival (DOA) of an acoustic source. Beamformers operate using at least two sensors that look among a set of geometrical directions for the one that maximizes received signal power. In this paper we consider a two-sensor beamformer that estimates the DOA of a single source by scanning the broadside for the direction that maximizes the mutual information between the two microphones. This alternative approach exhibits robust behavior even under heavily reverberant conditions where traditional power-based systems fail to distinguish between the true DOA and that of a dominant reflection. Performance is demonstrated for both algorithms with sets of simulations and experiments as a function of different environmental variables. The results indicate that the newly proposed beamforming scheme can accurately estimate the DOA of an acoustic source.