Judgments of disfluency by mothers of stuttering and normally fluent children.

The purpose of this study was to examine the relation between selected aspects of speech disfluency and perceptual judgments of these events by mothers of young stutterers and mothers of age- and sex-matched normally fluent children. Each mother independently listened to and judged as either "stuttered" or "not stuttered" recorded examples of a young stutterer's imitated productions of: (a) five different types of speech disfluency, (b) sound prolongations, and (c) sound/syllable repetitions of five different durations each, along with a comparable number of fluent utterances. Results indicated that although some between-group differences in judgments were observed, both groups most frequently judged sound/syllable repetitions to be stuttered, followed by whole-word repetitions and broken words. Fluent utterances, interjections, and sound prolongations were most frequently judged to be not stuttered by all mothers. Both groups judged sound prolongations averaging 258 ms in duration to be stuttered an average of 25% of the time, increasing to 68% for sound prolongations averaging 1254 ms; however, both groups of mothers judged sound/syllable repetitions of two or more iterations to be stuttered an average of 93% of the time. Findings suggest that there are not appreciable differences between mothers of stuttering and normally fluent children regarding their perceptual judgments of speech disfluencies, but each group might more frequently judge as stuttered those types of speech disfluencies characteristic of their own children's speech.