Language and disfluency in nonstuttering children's conversational speech

Abstract

Several recent theories have suggested that the production of speech disfluencies is related, in part, to certain aspects of language formulation. One common characteristic of these theories is the proposal that the same basic mechanism is responsible for disfluency in people who stutter as well as in people who do not stutter. To learn more about the connection between language formulation and fluency in nonstuttering speakers, this study examined relationships between syntactic complexity, utterance length, and disfluency in the spontaneous speech of 12 normally fluent children (six girls and six boys, age 44–64 months), who produced 50-utterance spontaneous speech samples during conversations with a speech–language pathologist. On average, disfluent utterances were longer and more syntactically complex than fluent utterances. Discriminant analyses indicated that utterance length in clausal constituents was the most important factor (among those assessed in this study) for predicting the likelihood that an utterance would be disfluent. Analysis of subjects' individual speech samples indicated that the selected aspects of linguistic complexity could only classify fluent and disfluent utterances at better than chance levels for a subgroup of subjects. Findings provide one means of evaluating theories that explain speech disfluencies based on normal language formulation process. Results also emphasize the value of considering individual patterns in children's speech fluency, and highlight the need to consider factors such as the timing of utterances or other contextual factors, in addition to linguistic complexity, in future studies of children's speech fluency.