Source models for fricative consonants

Abstract

Source parameters for models of fricative consonants were derived from experiments using mechanical models having the profile of midsagittal x rays given in Fant [Acoustic Theory of Speech Production (Mouton, The Hague, 1970)]. By positioning a pressure probe at several points along the wall of each model's tract, it was shown that sound‐generation characteristics of fricatives such as /s, ∫/ differ fundamentally from those of ç, x/ with regard to source location, source spectrum level at low frequencies, and the relationship between source spectrum amplitude and mean volume velocity. In both cases, sound is generated when turbulent air strikes relatively rigid boundaries. The angle of the boundary with respect to the flow of air is the significant factor in this case. For /s, ∫/, the obstacle is at right angles, for/ç, x/, the “obstacle,” the tract wall, is nearly parallel to the flow. Implications for vocal tract models will be discussed. [Work supported by a Hunt Fellowship awarded by the Acoustical Society, and a grant awarded by the North Atlantic Treaty Organization in 1984.]