Signal-based late residual echo spectral variance estimation

A commonly used technique to attenuate acoustic echo signals in hands-free devices is acoustic echo cancellation (AEC). In practice, the AEC is unable to provide sufficient echo reduction due to system misalignment, modeling errors and the insufficient length of the estimated acoustic echo path. Hence, AEC is usually used in conjunction with one or more postfilters to suppress the remaining echo. For the estimation of the postfilter the residual echo is required. In the past, several approaches have been proposed which estimate the late residual echo spectral variance using the far-end signal and parameters that are obtained from the estimated echo path. In this work, we propose a signal-based algorithm to estimate the parameters. Thus, among other advantages, the postfilter can also be used in combination with acoustic echo suppression.