Echo cancellation is one of the most important factors affecting the quality of speech communications using voice-over Internet protocol (VoIP), especially when users have discrete microphones and loudspeakers rather than a standard headset. Because the remote voice appears near the loudspeaker, both the near and far voices appear at the microphone. A new approach to aid the echo-cancelling algorithm embeds a hidden watermark signal into the arriving signal. Detecting this signature allows the algorithm to stop or restart the process of the adaptive echo cancellation.
This paper costs $33 for non-members and is free for AES members and E-Library subscribers.