On the problem of detection and discrimination of double talk and change in the echo path

The problem of detection and discrimination of double talk and change in the echo path in a telephone channel is consid ered A change in echo path requires fast adaptation of the channel model to be able to equalize the echo dynamics On the other hand the adaption rate should be reduced when double talk occurs Thus it is critical to quickly detect a change in echo path while not confusing it with double talk which gives a similar e ect The proposed likelihood based approach compares a global channel model with a local one over a sliding window both estimated with the Recursive Least Squares algorithm