Patent ID: 7558636

Claim:
A method of providing a time domain digital output signal corresponding to a time domain input signal comprising: (a) converting said time domain input signal into one or more frequency domain input signals; (b) for each of said frequency domain input signals: (i) providing a signal index corresponding to said each of said frequency domain input signals to characterize each of said frequency domain input signals as containing a desirable signal or one of a plurality of different types of noise based on various characteristics of different types of noise and desired signals wherein the method includes providing at least a first sub-index corresponding to a change in a first characteristic of the corresponding frequency domain input signal and a second sub-index corresponding to a change in a second characteristic of the corresponding frequency domain input signal, and providing a signal index determined from the first and second sub-indices; (ii) providing a gain signal corresponding to said signal index; and (iii) amplifying or attenuating said each of said frequency domain input signal in response to said gain signal to provide a frequency domain output signal; and (c) combining said frequency domain output signals to provide said time domain output signal.