Patent ID: 9087501
Filing Date: 2015-07-21
Classification: G10H

Abstract:
1. A sound signal analysis apparatus comprising: at least one non-transitory memory device; at least one processor; a sound signal input portion for inputting a sound signal indicative of a musical piece; a tempo detection portion for detecting a tempo of each of sections of the musical piece by use of the input sound signal; a judgment portion for judging stability of the tempo; and a control portion for controlling a certain target in accordance with a result judged by the judgment portion, wherein the tempo detection portion has: a feature value calculation portion for calculating a first feature value indicative of a feature relating to existence of a beat and a second feature value indicative of a feature relating to tempo for each of the sections of the musical piece; and an estimation portion for concurrently estimating a beat position and a change in tempo in the musical piece by selecting, from among a plurality of probability models described as sequences of states classified according to a combination of a physical quantity relating to existence of a beat in each of the sections and a physical quantity relating to tempo in each of the sections, a probability model whose sequence of observation likelihoods each indicative of a probability of concurrent observation of the first feature value and the second feature value in the each section satisfies a certain criterion, wherein the sound signal input portion, the tempo detection portion, the judgment portion, and the control portion are implemented at least in part by the at least one processor executing at least one program recorded on the at least one non-transitory memory device.