A New Structure for Combining Echo Cancellation and Beamforming in Changing Acoustical Environments

This paper proposes a new robust structure for combining acoustic echo cancellation and microphone array beamforming. The new structure employs short adaptive filters in the acoustic echo cancellers that precede the beamformer, allowing for quick tracking of time variations within the hands-free environment. The beamformer is followed by a single echo canceller to further suppress echo. Simulations show that by taking into consideration the dynamic behaviour of the hands-free environment, the proposed structure reconverges faster compared to standard combined structures during changing acoustical environment conditions. An improvement in ERLE of up to 10 dB is observed during reconvergence.