US Patent 7923621 Tempo analysis device and tempo analysis method

A tempo analyzer to analyze the tempo of sound such as a musical composition or the like is provided in which a controller (9) takes, based on level information on a sound signal from an analysis data extraction unit (62), a frame which is a predetermined unit-time interval as a unit of process, detects positions of peaks of the level of the sound signal (apex of the change in level) higher than a predetermined level to find a time interval (peak-to-peak interval) between the peak positions in the frame, and determines a peak-to-peak time interval having occurred frequently as a tempo.