Patent ID: 7224810

Claim:
A method of noise reduction comprising: sampling an audio signal at a sample rate f; converting the audio signal to a digital signal in time domain; for each of a series of frames of time, converting the digital signal in the time domain to a digital signal in frequency domain for the frame of time; wherein the converting includes determining a set of frequency domain values, the frequency domain values in the set created by a set of digital filters, the digital filters related to each other by a constant ratio of filter bandwidth to center frequency, related to a perceptual scale for auditory processing; obtaining a set of minimum magnitude frequency domain values including, at each frequency represented by the frequency domain values, a frequency domain value having a minimum magnitude from among frequency domain values for such frequency over a time interval spanning multiple frames of time; subtracting the set of minimum magnitude frequency domain values from the audio signal in frequency domain, for a particular frame of time; converting the subtracted audio signal to time domain; and outputting the converted audio signal.