Acoustic characteristics of fricatives and fricative‐like models

Abstract

Spectra of spoken fricatives and of the output of mechanical models designed to mimic fricatives were compared in order to test the applicability of such models to speech, and to explore the acoustic mechanisms of fricative production. Power spectra were computed from recordings of five speakers uttering the sustained fricatives [φ, f, θ, s, s, x]. Mechanical models were assembled using a variety of articulatory and aerodynamic data, guided by previous work with models [C. Shadle, J. Acoust. Soc. Am. Suppl. 1 75, S24 (1984)]. The models fell into three groups according to source location and type. To produce [s, s] an obstacle is required at the approximate location of the teeth. A very short front cavity is required for [φ, f, θ]; the jet of air must be located near the tube wall or other surface to mimic the role of the lips. For [x, c] the palate and possibly alveolar ridge act as a turbulence‐generating surface anterior to the constriction. Although perfect spectral matches are not attained in all cases, the mechanical models can be used to test the adequacy of source‐filter representations of the fricatives. [Work supported by NINCDS.]