ADAPTIVE NOISE REDUCTION SYSTEM AND UNKNOWN SYSTEM TRANSFER CHARACTERISTIC IDENTIFYING METHOD USING THE SAME

摘要

PURPOSE: To reduce an influence of a desired signal to perform a proper cancel operation for the noise. ;CONSTITUTION: A noise signal correlated with the noise signal in a principal input signal is supplied as a reference input signal to a first adaptive filter means 24 to from a signal approximating the noise in the principal input signal. The output signal of the adaptive filter means 24 is subtacted from the principal input audio signal to cancel the noise. The adaptive filter means 24 adaptively updates the coefficient of the filter so that the output power of a estimated error is minimized. A third sound collecting means which collects desired sounds and a second adaptive filter means 34 which generates a signal approximating the desired audio signal from the output signal of this third sound collecting means 34 are provided. The output signal of the second adaptive filter means 34 is used to reduce or eliminate the desired sounds in the output signal of a first synthesizing means, and the signal which does not include the desired audio signal is supplied as the probable error to the first adaptive filter means 24.;COPYRIGHT: (C)1994,JPO