| 摘要 |
PROBLEM TO BE SOLVED: To estimate pitch with a high degree of accuracy. SOLUTION: A pitch estimation section 10 estimates a fundamental frequency F0 of an object sound, from a probability density function P of a fundamental frequency for indicating a weight valueω[F] of each sound model M[f], when modeling the object sound as a mixed distribution of a plurality of sound model M[F] for indicating a harmonics structure. An index calculation section 50 calculates a note number index value N according to the number of note for constituting the object sound. A control section 60 controls processing by the pitch estimation section 10 on the basis of the note number index value N. For example, the control section 60 controls an iteration cycle m of the unit processing according to the note number index value N, in a structure in which the pitch estimation section 10 estimates the probability density function P by iteration of unit processing for updating the weight valueω[F]. Moreover, the control section 60 controls a threshold Pth on the basis of the note number index value N, in a structure in which the pitch estimation section 10 estimates a peak frequency more than the threshold Pth in the probability density function as the fundamental frequency F0 of the object sound. COPYRIGHT: (C)2008,JPO&INPIT
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