Nonlinear Residual Echo Suppression using a Power Filter Model of the Acoustic Echo Path

Abstract

Loudspeakers and amplifiers of mobile communication receivers may cause significant nonlinear distortion in the acoustic echo path, resulting in a limitation of the performance of linear echo cancelers. In this contribution, we present a nonlinear acoustic echo suppressor in order to increase the attenuation of the nonlinearly distorted residual echo. The proposed approach is based on a power filter model of the acoustic echo path which is applied to the estimation of the power spectral density of the nonlinear residual echo. These time-variant estimates are used to appropriately adjust the frequency-dependent gain values of the echo suppressor. The performance of the proposed approach is evaluated in realistic experimental set-ups.