METHOD AND APPARATUS FOR IMPROVED RESIDUAL ECHO SUPPRESSION AND FLEXIBLE TRADEOFFS IN NEAR-END DISTORTION AND ECHO REDUCTION

摘要

A system and method is described for estimating residual echo and performing residual echo suppression on a signal. In particular, the system and method described herein: 1) provides a more accurate coherence-based approach where the sub-band nature of coherence-based residual echo estimation is leveraged using sub-band-based coherence measures and upper-bound envelopes to guide residual echo estimates; 2) provides joint estimation of the residual echo and a background stationary noise-floor; 3) provides more accurate residual echo estimation by combining the above two measures with information on near-end activity to selectively adjust the residual-echo estimation in sub-bands; and 4) provides improved control of near-end distortion by leveraging the noise-floor estimate and the internally calculated signal-to-echo ratios as additional guides/limits to help balance, flexibly, and as needed, near-end distortion with residual echo suppression. The resultant residual echo suppressor design provides significant improvement in both residual echo suppression and background noise preservation.

主权项

1. A method for suppressing residual echo, comprising:
detecting sound by a microphone at a near-end location to produce a microphone signal; performing echo cancellation on the microphone signal to remove a portion of the echo, wherein performance of echo cancellation generates an echo cancelled signal and an estimate of the linear echo component of the echo; converting the echo cancelled signal and the estimate of the linear echo component to the frequency domain; estimating echo leakage based on the frequency domain echo cancelled signal and the frequency domain estimate of the linear echo component to produce initial echo leakage values for sub-bands of the frequency domain echo cancelled signal; adjusting the initial echo leakage values based on a statistical analysis between the initial echo leakage values to generate final echo leakage values; and generating a final residual echo estimate based on the final echo leakage values.