Control of short lag VOT (voice-onset time) for voiced English stops

Abstract

The American English stops /b/, /d/, and /g/ are produced with negative VOT (−150–0 ms) or short-lag VOT (0–30 ms). These two variants have been shown to occur with approximately equal frequency across speakers, although individual preferences are common. It has been hypothesized that the characteristic VOTs of short-lag stops are determined by relatively simpler articulatory control mechanisms than negative VOT variants. Specifically, if the vocal folds are approximated prior to constriction release, and intraoral pressure is vented only at the point of maximum constriction (without supraglottal expansion), the VOT will be determined by the venting process controlled by the time-varying constriction aperture. Thus, the release kinematics could account for effects of place of articulation and vowel context on short-lag VOTs. In the current work, the plausibility of this hypothesis is evaluated. The kinematics of constriction release gestures was examined from x-ray microbeam data. Descriptions of the time-varying geometries of constriction releases were input to a simple model of breath-stream dynamics and simulated VOT values were obtained. The descriptive and simulated data are consistent with the hypothesis that the characteristic durations of short-lag VOTs are determined by the venting process controlled by the supraglottal stop release gesture.