Adaptive Eigenvalue Decomposition Algorithm for Passive Acoustic Source Localization

To find the position of an acoustic source in a room the relative delay between two (or more) microphone signals for the direct sound must be determined. The generalized cross-correlation method is the most popular technique to do so and is well explained in a landmark paper by Knapp and Carter. Since this work (published in 1976) not many new ideas have been proposed and not much has been done to deal with the difficult problem of reverberation. In this memo, a new approach is proposed that is based on eigenvalue decomposition. Indeed, the eigenvector corresponding to the minimum eigenvalue of the covariance matrix of the microphone signals contains the impulse responses between the source and the microphone signals (and therefore all the information we used for time delay estimation). In experiments, the proposed algorithm performs well and is very accurate.