The supraglottal articulation of prominence in English: linguistic stress as localized hyperarticulation.

The results of an articulatory investigation of the supraglottal correlates of linguistic prominence in English, and a proposal of a unified description of linguistic stress are reported. Three models of stress are evaluated: that prominence expands jaw movement, that stress expands an abstract articulatory scale involving the opening and closing of the vocal tract, and that stress involves a localized shift toward hyperarticulate speech. A corpus of x-ray microbeam records of sensible speech is studied, within which the stress pattern is controlled and is checked by means of an intonational analysis. Jaw movement data yield similar results to earlier studies, but kinematic differences interpreted with reference to a gestural theory suggest that different subjects use different articulatory strategies to articulate stress contrasts. In addition, the jaw, lip, and tongue interact in the articulation of stress in subject dependent ways. Thus the articulation of stress should be formulated in terms of abstract articulatory goals, rather than in terms of individual articulator positioning. Finally, the data show that stress affects the articulation of nonsonority distinctions such as backness in vowels and point of articulation in consonants. A hyperarticulation model of stress is discussed in terms of these results.