Active binaural sound localization

Estimating the direction of arrival of sound in three dimensional space is typically performed by generalized time-delay processing on a set of signals from an array of omnidirectional microphones. This requires specialized multichannel A/D hardware. Our work is motivated by the desire to only use standard two-channel audio A/D, which is commonly available on personal computers. To estimate direction of arrival of sound, we change the pose of the microphones by mounting them on a computer-controlled pan-and-tilt unit. In this paper, we describe two approaches. The first uses two omnidirectional microphones on a fixed baseline, which has two rotational degrees of freedom. The second uses a directional microphone with two rotational degrees of freedom. We show algorithms for estimation of sound direction of arrival using these configurations. Preliminary experimental results demonstrate the feasibility of the approach.