The private life of stops: VOT in a real-time corpus of spontaneous Glaswegian

While Voice Onset Time (VOT) is known to be sensitive to a range of phonetic and linguistic factors, much less is known about VOT in spontaneous speech, since most studies consider stops in single words, sentences and/or in read speech. Scottish English is typically said to show less aspirated voiceless stops than other varieties of English, but there is also variation, ranging from unaspirated stops in vernacular speakers to more aspirated stops in Scottish Standard English; change in the vernacular has also been suggested.This paper presents results from a study which used a fast, semi-automated procedure for analyzing positive VOT, and applied it to stressed syllable-initial stops from a realand apparent-time corpus of naturally-occurring spontaneous Glaswegian vernacular speech. We confirm significant effects on VOT for place of articulation and local speaking rate, and trends for vowel height and lexical frequency. With respect to time, our results are not consistent with previous work reporting generally shorter VOT in elderly speakers, since our results from models which control for local speech rate show lengthening over real-time in the elderly speakers in our sample. Overall, our findings suggest that VOT in both voiceless and voiced stops is lengthening over the course of the 20 th century in this variety of Scottish English. They also support observations from other studies, both from Scotland and beyond, indicating that gradient shifts along the VOT continuum reflect subtle sociolinguistic control. 1 This paper substantially extends an earlier study which gave preliminary results for 12 speakers (Stuart-Smith et al. 2015). JSS is very grateful to the Leverhulme Trust for the funding which supported this research (RPG-142). MS was supported by the Social Sciences and Humanities Research Council (430-2014-00018) and the Fonds de recherche du Québec – Société et culture (183356). We are very grateful to Cordula Klein for help with manual correction of the TextGrids, to Misha Schwartz for scripts to parse the TextGrids, and Thea Knowles for help with AutoVOT and comments on drafts. Audiences at ICLaVE7, NWAV34 and LabPhon14 have given us valuable feedback on earlier versions. We are also grateful to the two anonymous reviewers and to the editors of this special issue of Laboratory Phonology.