Patent Review : US5212764

Patent Review

The objective of the present invention is to provide a noise eliminating apparatus capable of effectively eliminating background noise components from a speech signal containing the same irrespective of the levels of the background noise components.Another objective of the present invention is to provide a noise eliminating apparatus in which coefficients for eliminating noise are renewed as many times aspossible so that background noise contained in a speech signal is effectively eliminated in response to a change of noise.The above-mentioned objectives of the present invention are achieved by a noise eliminating apparatus comprising: 

First feature extracting means for individually extracting a feature quantity X(f) (f = l, 2, . . . , n) of an input speech containing a noise for n channels 

(n is an integer);

Second feature extracting means for individually extracting a feature quantity N(f) of the noise for the 11 channels; and noise eliminating means, 

coupled to the first and second feature extracting means, for deriving a first noise eliminating variable k(f) and a second noise eliminating variable d(f) from the feature quantity X(f) of the input speech containing the noise provided for each of the n channels and the feature quantity N(f) of the noise provided for each of the n channels and for generating a feature quantity S(f) of a noise-eliminated input speech.