1. Takahashi, M., Yamamoto, G.: On the physical characteristics of Japanese vowels. Res. Electrotech. Lab. 326 (1931)
2. Furui, S., Akagi, M.: Perception of voice individuality and physical correlates. Trans. Tech. Com. Psychol. Physiol. Acoust. H85-18 (1985)
3. Zhu, W., Kasuya, H.: Perceptual contributions of static and dynamic features of vocal tract characteristics to talker individuality. IEICE Trans. Fundamentals E81-A, 268–274 (1998)
4. Imai, S.: Log magnitude approximation (LMA) filter. IEICE Trans. Fundamentals J63-A, 886–893 (1980)
5. Fujisaki, H., Hirose, K.: Analysis of voice fundamental frequency contours for declarative sentences of Japanese. J. Acoust Soc. Jpn (E) 5, 233–242 (1984)