Latency of Vocalization Onset: Stutterers Versus Nonstutterers

Abstract
Eleven stutterers and matched controls were asked to produce as quickly as possible each of 26 different syllables following a visual stimulus. Three trials were given for each syllable. Responses were filtered to remove supraglottally produced sounds, and the time between the visual stimulus and the onset of vocalization was measured by a voice-operated relay and a computer’s internal clock. The results suggested that stutterers are slower in initiating vocalization across a wide variety of syllables, and the difference averages about 65 msec. Furthermore, when phonologic conditions delayed voice onset by a comparable amount, the stutterers gained enough time so that no significant differences were observed between the two groups. The results are interpreted as suggesting that auditory dysfunction cannot be a cause for slower vocalization reaction time in stutterers but that either vocal dysfunction or a lack of cerebral dominance may be responsible for these differences.