ACOUSTIC SIGNAL ANALYSIS DEVICE, ACOUSTIC SIGNAL ANALYSIS METHOD, AND ACOUSTIC SIGNAL ANALYSIS PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide an acoustic signal analysis device capable of estimating a beat point and tempo in real time with high accuracy.SOLUTION: An acoustic signal analysis device 10 tentatively determines the presence of a beat and tempo in the current section on the basis of a probability model that is described as a series of states classified by a combination of a physical quantity relating to the presence of a beat in each section of a music and a physical quantity relating to tempo. The tentatively determined tempo is corrected on the basis of the tempo determined in a past section, and tempo in the current section is determined on the basis of the corrected tempo. A beat phase equivalent to a time till a beat point seen from the current section is calculated on the basis of the determined tempo. In a section in which it is tentatively determined that a beat exists and in which section the beat phase is included in a prescribed range and one or a plurality of sections that follow the section, the absolute value of the beat phase is corrected so that it is reduced by a prescribed correction value. It is determined that the beat exists in a section in which the positive/negative signs of the beat phase have changed, and the determination result is outputted together with the determined tempo.