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Pitch-period smoothing

Pitch-period smoothing (PP-smoothing) uses an estimate of the fundamental frequency (F0) to determine optimal parameters for spectral analysis and feature smoothing. The idea can be applied in a variety of ways, the most sophisticated of which is probably Kawahara's STRAIGHT analysis system. Some are listed below. In all cases, knowledge of the voice period (when the speech is voiced) allows parameters to be tailored to minimize voice-related fluctuations. In case one is tempted to dismiss the idea, because speech is not always voiced and because when it is F0 estimation is known to be unreliable, it should be stressed that these methods have a reasonable behavior when the speech is unvoiced, or the F0estimate wrong.

Alain de Cheveigne