The role of gestural phasing in Western Andalusian Spanish aspiration.

This study examines the phenomenon of post-aspirated voiceless stops in Western Andalusian Spanish in /s/ + voiceless stop sequences. Previous analyses have proposed that the post-aspiration arises through a reorganization of the glottal spreading gesture for /s/ and the oral constriction gesture for the stop. This theory is tested by steadily increasing speakers' production rate, which has been shown to trigger spontaneous changes in gestural organization in speech and other motor activities. Results from the study support the initial hypothesis. There is a switch from productions with with preaspiration and short VOT to those with long VOT as rate increases. Additionally, there is a tradeoff between VOT and pre-closure aspiration, indicating they may result from the same gesture. Lastly, the variability in production shows a number of hallmarks of phase transitions in human coordination. In sum, a change in gestural organization provides a simple explanation for post-aspirated stops in this dialect.