Robust Early Echo Cancellation and Late Echo Suppression in the Stft Domain

Acoustic echo arises due to acoustic coupling between the loudspeaker and the microphone of a communication device. Acoustic echo cancellation and suppression techniques are used to reduce the acoustic echo. In this work we propose to first cancel the early echo, which is related to the early part of the echo path, and subsequently suppress the late echo, which is related to the later part of the echo path. The identification of the echo path is carried out in the Short-Time Fourier Transform (STFT) domain, where a trade-off is facilitated between distortion of the near-end speech, residual echo, convergence rate, and robustness to echo path changes. Experimental results demonstrate that the system achieves high echo and noise reduction while maintaining low distortion of the near-end speech. In addition, it is shown that the proposed system is more robust to echo path changes compared to an acoustic canceller alone.