A method and apparatus are provided for reducing noise in a signal. Under
one aspect of the invention, a correction vector is selected based on a
noisy feature vector that represents a noisy signal. The selected
correction vector incorporates dynamic aspects of pattern signals. The
selected correction vector is then added to the noisy feature vector to
produce a cleaned feature vector. In other aspects of the invention, a
noise value is produced from an estimate of the noise in a noisy signal.
The noise value is subtracted from a value representing a portion of the
noisy signal to produce a noise-normalized value. The noise-normalized
value is used to select a correction value that is added to the
noise-normalized value to produce a cleaned noise-normalized value. The
noise value is then added to the cleaned noise-normalized value to
produce a cleaned value representing a portion of a cleaned signal.