Prosodic constraints on glottalization of vowel-initial syllables in American English

Abstract

Earlier work on the glottalization of vowel-initial syllables sought an account in terms of the morphosyntactic hierarchy and isolated intonational facts, without accounting for the possible role of prosodic constituent structure. In a corpus of digitized, prosodically labeled speech (FM radio news style, 371 vowel-onset syllables produced by a single female speaker), (a) a syllable which begins in intonational constituent and is pitch accented is likely to show a glottal onset (91%), (b) constituent-initial position and pitch accent each separately increase the likelihood of glottal onset (66% and 47%, respectively). Noninitial nonaccented syllables are much less likely to be glottalized (16%; some of these syllables may have a pitch accent that is small in comparison with the strongly realized accents often produced in FM news speech). Constituent-initial glottalization occurs even for reduced-vowel syllables, which earlier work suggested was rare: 83% of reduced-vowel syllables in constituent-initial position glottalized, but only 24% in noninitial position. Preliminary results for a second speaker show a similar pattern, illustrating both the value of revisiting earlier analyses with prosodic structure in mind, and the usefulness of a large prosodically labeled database of continuous speech.