Perceptually-Motivated Nonlinear Channel Decorrelation for Stereo Acoustic Echo Cancellation

Acoustic echo cancellation with stereo signals is generally an underdetermined problem because of the high coherence between the left and right channels. In this paper, the authors present a novel method of significantly reducing inter-channel coherence without affecting the audio quality. The work takes into account psychoacoustic masking and binaural auditory cues. The proposed non-linear processing combines a Shaped Comb-ALlpass (SCAL) filter with the injection of psychoacoustically masked noise. The authors show that the proposed method performs significantly better than other known methods for reducing inter-channel coherence.