Echo Reduction Using Wiener Gains Considering Short-Time Correlation Between Echo and Near-End Speech

This paper introduces a frequency-domain acoustic echo reduction process based on a new Weiner-filtering method assuming a short-time correlation between an acoustic echo and a near-end speech. The conventional echo reduction method based on Wiener filtering estimates the gain based on the assumption that acoustic echo and near-end speech are statistically independent. However, this assumption does not always hold true in practice because the gain is estimated in a very short period where the echo and near-end speech are not uncorrelated. As a result, the conventional method occasionally causes the perceptual degradation of sound quality during a double-talk situation; therefore, the performance is still not sufficient. Our goal was to accurately calculate the echo-reduction gain to decrease the speech distortions produced by the echo-reduction process. The proposed method solves a least mean square error of the Weiner-filtering method by taking into account the short-time correlation between echo and near-end speech to obtain a better echo-reduction gain. The performance of this method was demonstrated by simulation results in which speech distortions were decreased.