Acoustic correlates of utterance-initial glottal stop in ‘ōlelo Hawaiʻi

The phoneme inventory of ʻōlelo Hawaiʻi (Hawaiian) consonants includes glottal stop. Cross-linguistic work has shown that utterance-medially, including in ʻōlelo Hawaiʻi, this phoneme is frequently not produced with full glottal closure and is instead often realized as creaky phonation. However, there is little previous work on the acoustic properties of utterance-initial phonemic glottal stop. We compared acoustics measurements of utterance-initial glottal stop with utterance-initial vowels in data from 13 speakers of Modern ʻōlelo Hawaiʻi from Hilo. Measures indexed overall fundamental frequency, energy, spectral tilt (Residual L1*), and harmonics-to-noise ratios. While there was little evidence for prototypical creaky voice, reliable differences for all measures were present on the vowel. A Linear Discriminant Analysis of the data was also able to predict whether an utterance started with glottal stop based on the combination of these measures. Our results suggest that speakers of Modern ʻōlelo Hawaiʻi likely produce full glottal closure when this phoneme is utterance-initial, as opposed to utterance-medial. These results provide the first systematic analysis in any language of the influence of utterance-initial glottal stop on the acoustic properties of a following vowel.