Patent ID: 8064966

Claim:
A method of processing an audio signal in a “hands-free” telephone device, in particular a self-contained device that is suitable for being fitted removably in a motor vehicle, the device including a microphone for picking up a speech signal from a near speaker, and a loudspeaker for reproducing a speech signal from a remote speaker, the loudspeaker being suitable for giving rise to an interfering acoustic echo by coupling with the microphone, said audio signal processing method comprising: echo cancellation processing by implementing an adaptive linear filter algorithm, the algorithm being iterated at a given adaptation stepsize; processing for detecting and taking account of a double talk situation; and processing for evaluating an index representative of the degree of convergence or divergence of the adaptive linear filter algorithm; wherein said processing for detecting and taking account of a double talk situation comprises the steps consisting in: a) assessing whether at least one predetermined condition is satisfied, said condition relating to said index representative of the degree of convergence or divergence of the algorithm, as evaluated; b) deducing that a double talk situation has arisen on the basis of the result of the assessment in step a); and c) in the event of double talk arising, modifying at least one parameter of the adaptive linear filter algorithm, in response to detecting said double talk situation.