CONTROL OF ADAPTATION STEP SIZE AND SUPPRESSION GAIN IN ACOUSTIC ECHO CONTROL

摘要

Provided is an acoustic echo control solution for mobile devices with performance comparable to acoustic echo cancellation, yet with lower complexity and maintained robustness to timing mismatches between far-end and near-end audio signals. Rather than subtracting (or cancelling) an estimated echo from the near-end signal, the energy-based filter control system and algorithm suppresses the frequency bands of the near-end signal where echo is present. Echo suppression operations are performed in the frequency-domain, and therefore filtering corresponds to multiplication. An estimate of the echo channel from the far-end to the near-end is used to estimate the echo in the near-end signal. This echo channel estimation process is followed by construction of a suppression filter that includes a controllable suppression gain parameter.