Patent ID: 7016488
Filing Date: 2006-03-21
Classification: H04B

Abstract:
1. A method for performing non-linear processing of an audio signal for selectively preserving true background noise, comprising: receiving a receive path signal and a send path signal, wherein the send path signal comprises the true background noise; estimating an error signal based on the receive path signal and the send path signal to produce an estimated error signal level; selectively extracting the true background noise from the send path signal and estimating a noise level of the extracted true background noise to produce an estimated true background noise level based at least on the receive path signal and the error signal, wherein the true background noise is extracted when no near-end talker signal and no far-end talker signal is detected; selectively transmitting the extracted true background noise into the audio signal when the extracted true background noise is selectively extracted; injecting predetermined background noise into the audio signal when the extracted true background noise is not transmitted into the audio signal, wherein the predetermined background noise is selected from one of a plurality of noise types; comparing the estimated true background noise level to a predetermined criteria; and using the estimated true background noise level and the error signal level to selectively preserve, based on the comparing, the true background noise in the audio signal.