title: Vocal tract length perturbation and its application to male-female vocal tract shape conversion.
abstract: An alternative and complete derivation of the vocal tract length sensitivity function, which is an equation for finding a change in formant frequency due to perturbation of the vocal tract length [Fant, Quarterly Progress and Status Rep. No. 4, Speech Transmission Laboratory, Kungliga Teknisha Hogskolan, Stockholm, 1975, pp. 1-14] is presented. It is based on the adiabatic invariance of the vocal tract as an acoustic resonator and on the radiation pressure on the wall and at the exit of the vocal tract. An algorithm for tuning the vocal tract shape to match the formant frequencies to target values, such as those of a recorded speech signal, which was proposed in Story [J. Acoust. Soc. Am. 119, 715-718 (2006)], is extended so that the vocal tract length can also be changed. Numerical simulation of this extended algorithm shows that it can successfully convert between the vocal tract shapes of a male and a female for each of five Japanese vowels.
authors.affiliation: ATR Human Information Science Laboratories, 2-2-2 Hikaridai, Keihanna Science City, Kyoto 619-0288, Japan. seiji.adachi@ibp.fraunhofer.de
authors.forename: Seiji
authors.initials: S
authors.lastname: Adachi
authors.forename: Hironori
authors.initials: H
authors.lastname: Takemoto
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kitamura
authors.forename: Parham
authors.initials: P
authors.lastname: Mokhtari
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Honda
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D008433:Mathematics; D008954:Models, Biological; D012680:Sensitivity and Specificity; D012727:Sex Characteristics; D013016:Sound; D014827:Vocal Cords / Q000033:anatomy & histology* / Q000502:physiology; D014831:Voice / Q000502:physiology*