Pitch extraction apparatus for an acoustic signal waveform
AssigneeYamaha Corporation
InventorShigeki Fujii
Life of this patent
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Abstract
A pitch extraction apparatus for extracting (detecting)a pitch of an acoustic signal which includes circuitry for calculating the stability of the acoustic signal. The stability calculation exhibits a larger value as the amplitude of the acoustic signal is larger and when the frequency is low. Pitch extraction is performed using the calculated stability. In addition, a pitch extraction apparatus which includes a pitch extractor for extracting a pitch of an acoustic signal by discriminating whether or not an input is a voiced or voiceless sound. Based on the determination that the input is a voiceless sound, the input to or the output from the pitch extractor will be inhibited.
Claims14
A pitch extraction apparatus comprising:
- stability calculating means for calculating, on the basis of an acoustic signal, stability which exhibits a larger value when the amplitude of the acoustic signal is relatively larger and the frequency of the acoustic signal is relatively lower;
- multiplying means for calculating a product of said stability and said acoustic signal to provide a product signal;
- and
- pitch extraction means for extracting a pitch on the basis of the product signal output from said multiplying means.
Dependencies are inferred from the claim text.