Vowel spectrum variability due to the source-tract coupling
René Carré, Bernard Guérin · The Journal of the Acoustical Society of America · 1985
The importance of source-tract coupling on the formant frequencies and bandwidths has already been demonstrated. Moreover, the amplitude of each harmonic component is not stable when the coupling effect occurs (for /a/ vowel for instance) [R. Carré, “Vocal source-vocal tract coupling: effects on the vowel spectrum,” The fourth F.A.S.E. Symposium, Venezia (1981)]. This phenomenon has been studied for male and female vowels (/a/, /i/, /u/) and for increasing and decreasing fundamental frequency. Studies on voiced plosives are in progress. Harmonic amplitude variations up to 20 dB have been observed, the reference being given by covariance techniques during the closed glottis conditions. Consequences for speech synthesis and speech recognition will be discussed.