An electroglottographic study on the effect of following context on glottal constriction in Australian English coda /t/

To achieve inhibition of voicing for voiceless speech sounds, the glottis may be either spread or constricted. Glottal spreading may lead to breathiness, and constriction to glottalization. Previous research has shown that glottalization associated with English coda /t/ differs as a function of surrounding environment, with glottalization more likely when the following word begins with a sonorant consonant (such as /l, n/) compared to other environments. However, it is unclear the extent to which following sonorant consonants induce glottalization compared to following vowels. We used an electroglottograph to record 12 Australian English speakers producing phrases eliciting coda /t/ in target words preceding words with onset sonorants /n, l/ (now, long) and onset vowels /əʉ, ə/ (only, again). Open quotient (OQ) was established through the second half of the target word vowel. Increasing OQ indicates breathiness whereas lowering OQ indicates constriction. Using generalized additive mixed modelling we found that the OQ of vowels preceding coda /t/ in the sonorant-following context was significantly lower than in vowel-following contexts. This indicates greater glottal constriction when a sonorant consonant follows the coda /t/, showing that coda /t/ voicelessness is implemented differently before sonorant consonants compared to vowels