Disfluencies and phonological revisions in a nonword repetition task in school-age children who stutter

Abstract

Phonological encoding and associated functions, including monitoring of covert and overt speech, have been attributed relevant roles in stuttering. The aim of this study was to investigate these processes by testing the effects of nonword length in syllables (3-, 4-, 6-syllable), phonotactics, and phonemic/phonetic complexity on disfluencies and phonological revisions in 26 school-age children who stutter (CWS, n = 13) and matched fluent controls (CWNS). Participants repeated nonwords in two sessions separated by an hour. Within-group comparisons of percentage disfluencies using nonparametric tests resulted in significantly more disfluencies for the 6- compared to the 3-syllable nonwords and suggested that nonword length influences disfluencies in the CWS. The groups were comparable in the percentage of disfluencies at all levels of nonword length. The findings failed to provide conclusive evidence that phonological complexity and phonotactic manipulations have a greater effect on disfluencies in CWS compared to CWNS. The findings of significantly fewer phonological revisions and the lack of a significant correlation between disfluencies and revisions in the CWS in Session 1 compared to the CWNS are interpreted to suggest reduced external auditory monitoring. Demands on incremental phonological encoding with increasing task complexity (the Covert Repair Hypothesis, Postma & Kolk, 1993) and reduced external auditory monitoring of stuttered speech can account for the disfluencies, speech errors, and revisions in the speech of school-age CWS.