Speech processing in the watermarked domain: Application in adaptive Acoustic Echo Cancellation

Audio watermarking, or embedding information in a host signal was originally used for digital copyright protection purposes. As audio coding, watermarking is progressively brought in audio processing applications.In this paper, we investigate some benefits of watermarking in signal processing. We focus here on a generic application: adaptive Acoustic Echo Cancellation (AEC). The proposed Watermarked AEC (WAEC) is based on a coupling of two adaptive filters. The first one extracts a rough estimation of the echo response to the known stationary watermark embedded in the speech signal. This extracted estimation constitutes the reference signal for the second adaptive filter. Driven by the known watermark, the second adaptive filter estimates then the actual echo path. The goal here is to drive the estimation of the echo path by the watermark itself, in order to take advantage of its optimal properties (whiteness and stationarity). As expected, the proposed WAEC exhibits better transient and steady state performance than the classical one. These results of some interest follow from the fact that the second adaptive filter deals with much more stationary signals that the first one.