Method of, and apparatus for, planar audio tracking

Abstract

A planar audio tracking system comprises a square array of four microphones (M, M, M, M) arranged as first and second cross-dipole microphones and a virtually constructed monopole microphone. The signals from these microphones undergo directional pre-processing and the results are applied to a filtered sum beamformer (FSB) (). The FSB identifies functions (h(0), h(π/2), and h) of the FSB which are representative of impulse responses from desired audio source(s) to the first and second cross-dipole and the monopole microphone, respectively. The functions of the first cross-dipole and the monopole microphones and the functions of the second cross-dipole and the monopole microphones are cross correlated to produce respective estimates (ψ(l) and ψ(l)) representative of the lag of the most dominant audio source. An angle-estimate ({circumflex over (φ)}) of the most dominant source is determined using the estimates of lag. Other embodiments of the tracking system may comprise 3 microphones arranged in a circular array and forming first and second cross-dipoles and a virtual monopole.