Patent ID: 8184828
Filing Date: 2012-05-22
Classification: G10L

Abstract:
1. A system for estimating the background noise in a loudspeaker-room-microphone system, where a loudspeaker is supplied with a source signal and a microphone senses the source signal distorted by the room and provides a distorted signal, the system comprises: an adaptive filter that receives the source signal and the distorted signal, and provides an estimated signal; a difference unit that provides an error signal indicative of the difference between the estimated signal and the distorted signal; a post filter that receives and filters a signal indicative of the error signal and provides a post filtered error signal; a spectral domain smoothing filter that receives the post filtered error signal and provides a spectral domain estimated-noise signal representing the estimated power spectral density of the background noise present in the room; a time domain smoothing filter that receives a first signal indicative of the post filtered error signal and provides a time domain estimated-noise signal representing the estimated mean power of the estimated background noise present in the room; a scaling factor calculation unit that receives a second signal indicative of the time domain estimated-noise signal and a third signal indicative of the spectral domain estimated-noise signal and provides a scaling factor; and a scaling unit that receives the scaling factor and applies the scaling factor to the spectral domain estimated-noise signal to provide an enhanced estimated-noise signal.