Acoustic echo cancellation for surround sound using perceptually motivated convergence enhancement

Acoustic echo cancellation (AEC) has become an essential and well-known enabling technology for hands-free communication and human-machine interfaces. AEC for two or more reproduction channels aims at identifying the echo paths between the microphone and each audio reproduction source in order to cancel the associated echo contribution. A number of preprocessing methods have been proposed to decorrelate stereo audio signals in order to enable an unambiguous identification of each echo path and to thus ensure robustness to changing sound source locations. While several of these methods provide enough decorrelation to achieve proper AEC convergence in the stereo case, considerations of subjective sound quality have frequently not been addressed adequately. This paper compares the performance of several methods in terms of both convergence speed and aspects of sound perception, and proposes a novel signal decorrelation approach with attractive properties. The superior performance of the proposed method is demonstrated for 5.1 surround sound reproduction.