Patent ID: 8098813

Claim:
A method for removing an echo component in a first signal received at an audio input device, said method comprising the steps of: outputting a second signal from an audio output device; receiving at the audio input device the first signal wherein the echo component in the first signal is the result of the second signal traversing an echo path; detecting if the first signal only comprises the echo component; determining an estimate indicative of the echo path by comparing the first signal and the second signal when it is detected that the first signal only comprises echo; applying the estimate indicative of the echo path to the first signal to determine an equalised first signal, the equalised first signal providing an estimate of the second signal that would have created the first signal after passing through the echo path; comparing the equalised first signal with the second signal to determine an estimate indicative of the echo component; and removing the echo component from the first signal in dependence on the estimate indicative of the echo component; wherein the step of detecting if the first signal only comprises the echo component comprises comparing a characteristic of the equalised first signal to a characteristic of the second signal.