Voice-onset time and electroglottographic dynamics in stutterers' speech: implications for a differential diagnosis.

Three stuttering subjects were used to test findings that voice-onset time (VOT) in the fluent utterances of stuttered speech are slower than those of their normal-speaking peers. Acoustic analysis revealed the stutterers' VOTs to be slower, but when analysed by a t test the difference was found not to be significant at the P = 0.05 level. Electroglottographic (EGG) dynamics were also studied to provide comparative data for recent research which notes specific EGG activity amongst stutterers following severe blocks. Analysis revealed that both experimental and control subjects exhibited this pattern randomly. It is concluded that, at present, EGG methodology is not sufficiently advanced to be able to characterise reliably the range of laryngeal behaviours that are associated with stuttering. The technique therefore is not presently viable as a diagnostic tool.