Investigation of several types of nonlinearities for use in stereo acoustic echo cancellation

In this paper, we investigate several types of nonlinearities used for the unique identification of receiving room impulse responses in stereo acousti c echo cancellation. The effectiveness is quantified by the mutual coherenc e of the transformed signals. The perceptual degradation is studied by psyc hoacoustic experiments in terms of subjective quality and localization accu racy in the medial plane. The results indicate that, of the several nonline arities considered, ideal half-wave rectification and smoothed half-wave re ctification appear to be the best choices for speech. For music, the nonlin earity parameter of the ideal rectifier must be readjusted. The smoothed re ctifier does not require this readjustment, but is a little more difficult to implement.