ECHO SUPPRESSOR AND NON-LINEAR PROCESSOR OF ECHO CANCELLER

摘要

ABSTRACT The invention relates to an acoustic echo suppressor and a non-linear processor for an echo canceller in a 4-wire data transmission network. An echo canceller is typically controlled by comparing the power levels (PWR|N, ' PS|N) of the near-end and far-end signals (RIN, 8IN). The transfer function of an acoustic echo path is usually very non uniform. According to the invention, the spectrum of the far-end signal (R|N) is treated, before the signal power level is calculated, with a weighted filter (21), which models the effect of the transfer function of acoustic echo. As a result, the double talk dynamics is improved, since high-energy vowels of far-end speech, which normally cause low-energy vowels of near-end speech to be clipped in an echo suppressor, will be attenuated.