Effect of emphasis spread on VOT in coronal stops in Qatari Arabic

Emphasis (contrastive pharyngealization of coronals) in Arabic spreads from an emphatic consonant to neighboring segments. Previous research suggests that in addition to changing spectral characteristics of adjacent segments, emphasis might affect voice onset time (VOT) of voiceless stops because emphatic stops in Arabic dialects have considerably shorter VOT than their plain cognates. No study investigated whether emphatic co-articulation could shorten VOT in plain stops produced in emphatic environment. The present study investigates changes in VOT in syllable-initial /t/ using production data from sixteen speakers of Qatari Arabic, who read non-word syllables with initial plain and emphatic stops /t/ and /ṭ/ adjacent to another plain or emphatic consonant. The results show that emphasis spread is a gradient process that affects only spectral characteristics of segments, causing changes in vowel formants and spectral centre of gravity of stops. Long-lag VOT in plain /t/, however, was not shortened in emphatic syllables. The findings suggest that shorter VOT in voiceless emphatic stops in Qatari Arabic is not a mechanical aftermath of pharyngealization but, rather, a phonological requirement to maintain contrast between long-lag and short-lag VOT in plain and emphatic stops.