Völcker, Björn (Google Inc., Kungsbron 2, Stockholm, Sweden)
Kleijn, W. Bastiaan (School of Engineering and Computer Science, Victoria University of Wellington, New Zealand)
Modern echo control algorithms, both those based on echo cancellation and echo suppression, benefit from an external estimate of the delay between the loudspeaker and microphone signals. In echo suppression the external delay is used directly. In echo cancellation it lowers computational effort and reduces the probability of large errors, particularly in situations with signal distortion. We propose a delay estimation algorithm that, in its simplest form, counts for each candidate delay co-occurrences of particular events, such as “signal present”, in the two signals. The method has low complexity and is robust against (linear and) nonlinear signal distortion. Our experiments on representative signals confirm that the method performs significantly better than conventional procedures while reducing computational complexity and memory requirements.