The disclosure includes description of a method of noise reduction
according to one possible implementation. An audio signal is sampled at a
sample rate f. The audio signal is converted to a digital signal in the
time domain. For each of a series of frames of time, the digital signal
in the time domain is converted to a digital signal in frequency domain
for the frame of time. The converting includes determining a set of
frequency domain values. The frequency domain values in the set are
created by a set of digital filters, and the digital filters are related
to each other by a constant ratio of filter bandwidth to center
frequency, related to a perceptual scale for audio processing. A set of
minimum magnitude frequency domain values is obtained. These values
include, 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. The set of minimum magnitude frequency domain values are
subtracted from the audio signal and the frequency domain, for a
particular frame of time. The subtracted audio signal is converted to the
time domain, and the converted audio signal is output. The disclosure
also includes description of a communication device, a playback device, a
multimedia recording device, a recording device, and other devices and
processes.