Subglottal pressure and final lowering in English

Quantitative models of intonation in a variety of languages typically specify a long-range down-trend across a sentence that provides a declining backdrop for the steeper rises and falls of more local pitch events such as accents and word tones. Studies of this declination in English and several other languages have isolated a component of somewhat steeper decline that covers only the last few centiseconds of laboratory speech utterances. This final lowering may be particular to utterances with a declarative intonation pattern, and that it is associated particularly with the ends of discourse units. Thus final lowering seems to be associated pragmatically with a sense of fading off or finality. To see whether final lowering can be attributed in part to a fading off of subglottal pressure, we examined the two measures together in two databases of utterances that varied in intonation contour. To minimize confounds from more local pitch specifications, we looked at the relationship between final lowering and subglottal pressure only in the intonational tail-i.e. the portion of the contour after the last pitch accent. The slope of the decline of the subglottal pressure varied as a function of the phonological specification of the tones in the tail. Utterances with declarative intonation or with any other contour sharing the phonological specification of a low tone at the end of the tail consistently showed a decline in subglottal pressure, whereas utterances with yes-no question intonation or any other contour sharing the phonological specification of a final high tone showed lesser declines, or even increases