Relationship of length and grammatical complexity to the systematic and nonsystematic speech errors and stuttering of children who stutter

Abstract The purpose of this study was to evaluate whether increased utterance length and grammatical complexity are associated with changes in frequency of systematic speech errors (i.e., phonological processes, or sound changes affecting an entire class of sounds or sound sequence [Edwards & Shriberg, 1983] ), and nonsystematic speech errors (i.e., a word or string of words that apparently deviates from the speaker's intention, but that is not characteristic of the child's systematic [phonological process]) of children who stutter (CWS). Subjects were 10 boys (S's mean age = 50.6 months; SD = 13.07 months) who exhibited both stuttering and disordered phonology, each of whom was audiotaped and videotaped while interacting with his/her mother during a 30-minute play/conversation period. Twenty-five stuttered and 25 nonstuttered utterances from each subject's conversational speech sample were measured in terms of utterance length, grammatical complexity, and systematic and nonsystematic speech errors. An utterance was then categorized as “high” or “low” in length and grammatical complexity relative to the subject's median for each of the two variables, and then related to total frequency of systematic and nonsystematic speech errors. Results indicated that stuttered utterances were significantly more complex and longer than nonstuttered utterances; however, there were no significant differences in systematic and nonsystematic errors for either stuttered or nonstuttered utterances relative to the grammatical complexity or length of utterance. Findings were taken to suggest that increased length and/or grammatical complexity of an utterance does not influence the frequency of systematic and nonsystematic speech errors, but does seem, as others have shown, to influence the frequency of stuttering.