During mixing of two musical tracks, the variations in combined output volume are reduced by analyzing either the intrinsic amplitude at which each track was mastered or the output amplitude (i.e. subsequent to amplification of the audio signal), and modifying either the intrinsic amplitude or amplification...http://www.google.es/patents/US20020172379?utm_source=gb-gplus-sharePatente US20020172379 - Automated compilation of music
