Third International Conference on Spoken Language Processing (ICSLP 94)
In spite of several pioneering studies in the field, the acoustic, geometric and aerodynamic characteristics of fricative consonants are far from being completely understood. The work presented here aims at clarifying the relationships between the noise source spectrum and the vocal tract geometry and aerodynamics. It has been in part motivated by the need for knowledge of sources for articulatory synthesis. Transfer function and radiated sound spectra have been measured quasi-simultaneously on a subject producing sustained whispered vowels and voiceless fricative consonants at different speech effort levels. For the same human subject, an enhanced Electropalatography (eEPG) system has been used to determine the size and shape of the constriction independently of aerodynamically-based estimates. Source spectra have been obtained by a pseudo-inverse filtering technique. The dependency of overall SPL and source tilt upon the glottal area for vowels and upon the constriction area for fricatives and the flow in the vocal tract is quantified. A tendency of a slight increase of constriction area with speech effort has also been shown by both eEPG and aerodynamically determined areas, and could possibly be ascribed to the subject's strategies for producing different effort levels.
Bibliographic reference. Badin, Pierre / Shadle, Christine H. / Ngoc, Y. Pham Thi / Carter, J. N. / Chiu, W. S. C. / Scully, Ceila / Stromberg, K. (1994): "Frication and aspiration noise sources: contribution of experimental data to articulatory synthesis", In ICSLP-1994, 163-166.