Yairi E, Hall K D
Department of Speech and Hearing Science, University of Illinois at Urbana-Champaign.
J Commun Disord. 1993 Dec;26(4):231-44. doi: 10.1016/0021-9924(93)90018-6.
The purpose of this study was to compare duration characteristics of single repetitions of single-syllable words in the speech of preschool children who stutter (N = 15) recorded near the onset of their stuttering to those of control nonstuttering children (N = 18). Disfluent episodes were identified in audio tape recordings of the subjects' conversational speech. The digitized signals were analyzed by means of the CSpeech computer software (Milenkovic, 1987). Using visual displays of the sound-pressure waveforms, as well as spectrography, the durations of the first production of the word (1st Unit), the second production (2nd Unit), the silent interval, and the total disfluency were measured. There were no statistically significant differences between the two groups on any of these segments although there was a tendency for the stutters to exhibit shorter silent intervals between repeated units. Relative measures, however, indicated that the ratio of the 2nd Unit to the total disfluency was significantly larger for the stutterers than the controls. For both groups, the ratio of the 1st to the 2nd Unit was positive, that is, the first production of the word was longer than the second. There was also a tendency for the ratio of the silent interval to total disfluency to be smaller for the stutterers. Overall, there appears to be a tendency for repetitions of very early stutterers to be faster than repetitions of nonstuttering children.
