Effects of Glottalisation, Preceding Vowel Duration, and Coda Closure Duration on the Perception of Coda Stop Voicing.

Abstract

English has multiple potential acoustic cues to coda stop voicing, including the duration of the preceding vowel, the coda closure duration, and, in some varieties, glottalisation. Glottalisation associated with coda stops appears to be a recent change to Australian English (AusE) with younger speakers using glottalisation more than older speakers in production. Here we report on a study designed to examine AusE-speaking listeners' perception of cues to coda stop voicing. Listeners were presented with audio stimuli in which preceding vowel duration, coda closure duration, and the relative proportions of the rhyme that these occupy were manipulated and co-varied with the presence or absence of glottalisation. The results show that listeners used preceding vowel duration to cue coda stop voicing, and that coda closure duration was a weaker cue to voicing when not varied in conjunction with preceding vowel duration. In addition, glottalisation facilitated increased perception of coda voicelessness, even when paired with very long preceding vowels, which otherwise signal coda voicing. Although age-related differences in production have previously been reported, we found that both older and younger listeners used glottalisation similarly in perception. These results may provide support for a sound change led by a shift in perception.