Speech source localization in near field

In array signal processing, a plane wave and uncorrelated signal sources are assumed for the sake of simplicity (far-field and independent signal sources assumption). However, this far-field assumption does not always hold for a microphone array, resulting in distortion in the array output. The performance of DOA estimation is poor in the case of correlated signal sources. A microphone array model, based on the near field, is built. A new DOA algorithm is presented. The modified MUSIC algorithm is adopted to eliminate the effect of the correlated signal sources in the subspace method. This algorithm utilizes three dimensional (frequency, amplitude and orientation angle) searching for the spectrum peak; its effectiveness is verified by computer simulation.