When vowels glottalize without strictly aligning with prosodic boundaries: marking prosodic structure in American and Australian English

Abstract Vowel glottalization, as voice quality variation, occurs at phrase edges or under prominence, often in conjunction with resolving onsetless syllables or vowel-vowel hiatus. This study examines whether and how voice quality in two varieties of English, American and Australian, is manifested at phrase edges and under prominence in vowels that are neither strictly initial nor final. Analyses of spectral and noise measures show that both varieties utilize voice quality to signal prominence and boundaries, even in non-edge contexts. Specifically, increased glottalization reflects stronger laryngeal articulation in line with domain-initial and prominence-induced strengthening. Conversely, phrase-final positions are characterized by phrase-final creak, which is often observed with phrase-final weakening. While both varieties show similar vowel glottalization usage, Australian English tends to use voice quality more extensively to mark focus than American English, with a greater overall tendency toward glottalization. This suggests that the impressionistic difference perceived in the general use of voice quality between the varieties (more robust glottalized vowels in Australian English) stems from differences in the use of glottalization in marking prosodic structure. These findings underscore the role of non-contrastive voice quality in shaping prosodic structure across varieties while also revealing dialect-specific interactions between phonetics and prosody in its manifestation.