An articulatory-acoustic-aerodynamic analysis of [s] in VCV sequences

Previous studies of the effect of vowel context on fricatives show seeming contradictions in the case of /s/: acoustic analysis shows the greatest context effect, while aerodynamic analysis shows relatively little effect, for the same subject. In this study, aerodynamic, acoustic, and articulatory data for the same subject producing /s, z/ in a variety of contexts were compared systematically. The strong acoustic effect of the /u - u/ context exists with /z/ as well as /s/, and appears to arise from a whistle-like source mechanism caused by lip rounding; the main tongue constriction does not appear to be immune to vowel context. Our interpretation of aerodynamic data as constrictions in series can be generalized to include the influence of lip rounding, thus: for this speaker and for these speaker-like sequences, the area of the vocal tract constriction for /s/ is independent of the vowel context but the overall aerodynamic effect does vary with lip rounding. Our aerodynamic and acoustic data seem to be consistent; both support the view that some rounding extends into the /s/ fricative.