Multichannel Double-Talk Detector based on Fundamental Frequency Estimation

Multichannel acoustic echo cancellers aim at reducing the undesired acoustic coupling among microphones and loudspeakers in multichannel audio/video teleconferencing systems. In this scenario, double-talk refers to the situation in which there is an active speaker both in the remote room and in the local room. The detection of double-talk is one of the main issues to be faced in such systems to ensure a correct echo cancellation. Indeed, filters coefficients update has to be suppressed during double-talk in order to prevent the filter from diverging because of the presence of the local speaker. In this paper, a novel approach for double-talk detection is discussed based on the estimation of the fundamental frequency of the residual error signals through adaptive second-order notch filters. More specifically, simultaneous speaker activity in the remote and local rooms is revealed by exploiting the same frequency tracking introduced for multichannel decorrelation. Several experiments have been carried out to prove the effectiveness of the proposed approach also making comparison with other solutions of the state of the art.