time - scaled , sound signals are generated by mixing weighted time - and frequency - domain processed signals , the former signal generally representing speech - based signals while the latter representing music - based signals . the weights applied to each type of signal may be determined by a scaling factor , which in turn is related to the desired speed at which a listener desires to hear a sound signal . in one example of the invention , only stationary signal portions of an input sound signal are used to generate time - scaled processed signals . an adaptive frame - size may also be used to pre - process the separate signals prior to being weighted , which at least decreases the amount of unwanted reverberative sound qualities in a resulting sound signal . together , techniques envisioned by the present invention produce improved , speed adjusted sound signals .