COMBINED ACOUSTIC ECHO CANCELLATION, DEREVERBERATION AND NOISE-REDUCTION - A 2 MICROPHONE APPROACH

This paper presents new algorithms for acoustic echo cancellation and noise reduction which use two (or possibly more) microphone signals. I n contrast to the single microphone method the multimicrophone approac h can exploit the spatial coherence properties of sound fields which a rise from noise and reverberated speech. Besides the standard FIR echo canceller the proposed algorithms comprise an adaptive filter to elim inate non coherent signal components. The combined system achieves bet ter Erle than the FIR echo canceller alone, attenuates ambient noise, dereverberates near end speech, and possibly leads to implementations with reduced complexity. The paper analyzes the acoustical properties of typical environments, presents the algorithms and experimental resu lts.