Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)


Communication Sciences and Disorders

First Advisor

Paul R. Hoffman


Stuttering and nonstuttering children's articulatory timing abilities as measured by duration differences were compared as rate, stress and phonetic complexity were varied and both internal and external timing sources were used. Use of external timing sources resulted in within normal limit performance by the stutterers as compared to their nonstuttering peers. Significant average intrasubject variability occurred on phonetic complexity tasks involving a variable linguistic sentence and its reiterative counterpart and on a syllable expansion through clustering task. Use of internal timing sources resulted in within normal limit performance by the stutterers on both rate tasks but on only one of two stress tasks. Significant relative timing differences between the two groups were revealed on one reiterative sentence task and on one formulation of rate task. Significant average intrasubject variability between the two groups occurred on rate tasks using both external and internal timing sources. Results support the theory that stutterers are less skilled motorically when producing more complex utterances and exhibit disturbances in prosody. Future analyses of utterances involving extensive hierarchical changes in rate, stress and phonetic complexity are needed to reveal subtle differences between the timing abilities of stutterers and their nonstuttering peers. Stimuli should be taken from normal conversational speech in order to provide natural samples of emotional and linguistic interaction during fluent and disfluent speech production.