PITCH CLASS ESTIMATING DEVICE, PITCH CLASS ESTIMATING METHOD, AND PROGRAM

摘要

PROBLEM TO BE SOLVED: To estimate a fundamental frequency of a target sound (particularly, a mixed sound of a plurality of sounds) with high precision.

SOLUTION: The sound estimating device D estimates the fundamental frequency F0 of a sound signal V from a probabilistic density function P of fundamental frequencies being a distribution of weight values ω[F] of respective tone models M[F] when the sound signal V is modeled as a mixed distribution of a plurality of tone models M[F]. A weight value computing section 23 computes the weight value ω[F] based upon estimated shapes C[F] showing how much the tone models M[F] support a harmonic structure of the sound signal V. An estimated shape specifying section 21 specifies estimated shapes C[F] based upon an amplitude spectrum S of the sound signal V, and the tone models M[F] and weight values ω[F]. A similarity analyzing section 271 computes similarity index values R[F] showing whether the tone models M[F] are similar to the estimated shapes C[F] specified from the tone models M[F]. A weight value correcting section 273 decreases a weight value ω[F] of a fundamental frequency F, the nonsimilarity of which is indicated by the similarity index value R[F] among the weight values ω[F].

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