Echo canceller with both double-talk detector and path change detector

An echo canceller with both double-talk detector (DTD) and echo path change detector (PCD) is put forward. Double-talk detector is based on the activity detection of speech, using sub-filter to detect the near end talk, and enhancing its performance by adding a sliding window. The path change detector works by comparing the performance between main-filter and sub-filter. There is a problem when an echo canceller has both detectors: It´s hard to discriminate between echo and near end speech after path changes, which can cause the echo of far voice increase suddenly and this echo is similar to the near end voice. To solve this problem, we propose to change double-talk detection threshold after path change happened. In addition, using the short silence mute at the beginning of a call, some random sequences will be sent to initialize the filter. The simulation results show that the proposed echo canceller has a satisfactory performance during double-talk and path change.