Abstract: A double-talk detector (DTD) method of performing double-talk detection, an echo canceller, and a method of performing echo cancellation is used with an echo canceller (EC) to sense when an echo is corrupted by near-end speech (NES). The double-talk detector inhibits the adaptation of a synthesizing filter when NES is present, in order to avoid divergence of the adaptive algorithm. Due to the time varying properties of the echo path and the signal levels, a suitable decision threshold ensures the accuracy of the DTD. The double-talk detector utilizes an adaptive decision threshold which is capable of tracking variations in the echo path and signal/noise levels during a call.