Patent ID: 7218741

Claim:
An adaptive differential microphone array method comprises: receiving a signal; estimating a measured signal spectral covariance matrix of the signal; estimating a direction of arrival of the signal; determining a presence of a source of interest in the signal based on the direction of arrival of the signal, a noise spectral covariance matrix of the signal, and a source signal spectral power of the signal; estimating the noise spectral covariance matrix based on a determination of the presence of the source of interest and the measured signal spectral covariance matrix of the signal; estimating a source signal spectral power of the signal according to the presence of the source of interest the noise spectral covariance matrix and the noise spectral covariance matrix; and applying a differential microphone array filter to signal according to the direction of arrival, the noise spectral covariance matrix, and the source signal spectral power of the signal, wherein the noise spectral covariance matrix is adapted based on the presence of the source of interest over time.