逐次計算による音声ピッチ周波数の変動特性

Abstract

Humans have been talking to each other using some form of speech for at least 50000 years. Speech signal is classified as consonant and vowel. Though the consonant is a transient sound, and has little power, the vowel has large signal power because it is quasi-periodic signal which determines main characteristics of speech signal. It is abbreviated as fundamental frequency or pitch of sound. This paper states a successive method to estimate average pitch frequency by using exponentially weighted infinite sum of instantaneous pitch frequencies. Our second aim is to calculate pitch deviation which is measured from its average frequency, applying the same manner stated above. Responces of average frequency and deviations for the signal having sinusoidal frequency modulation are discussed. And transient characteristics are also investigated. As an experiment, calculated results of average pitch frequencies and deviations for several speech signals are shown.