Patent ID: 6982377

Claim:
A method of time-scale modification of a digital audio signal comprising the steps of: separating the digital audio signal into a plurality of frequency bands; detecting the energy in each frequency band; determining the frequency band having the highest energy; separately time-scale modifying each of the plurality of frequency bands producing corresponding time-scale modified frequency band signals by analyzing each frequency band in a set of first equally spaced, overlapping time windows having a first overlap amount S a , selecting a base overlap S s for output synthesis corresponding to a desired time scale modification, calculating a measure of similarity between overlapping frames of the frequency band having the highest energy for a range of overlaps between S s +k min to S s +k max of the single audio signal, where k min is a minimum overlap deviation and k max is a maximum overlap deviation, determining an overlap deviation k m yielding the largest measure of similarity for the frequency band having the highest energy, calculating a measure of similarity between overlapping frames of frequency bands other than the highest energy frequency band for a range of overlaps around k m smaller than the range between S s +k min to S s +k max , determining an overlap deviation k i yielding the largest measure of similarity for each frequency band other than having the highest energy frequency band, synthesizing an output signal for each frequency band in a set of second equally spaced, overlapping time windows having the corresponding determined overlap amount; and combining the separate time-scale modified frequency band signals.