The relevance of DAF-induced speech disruption to the understanding of stuttering

The literature on delayed auditory feedback (DAF) repeatedly makes reference to the occurence of disfluencies under DAF in nonstutterers. However, no attempt has been made to determine the relative frequency of occurence of various types of disfluencies in nonstutterers under DAF. The present study investigated the frequency of occurence of various types of disfluencies in normal-speaking subjects in five successive oral readings under DAF. Twenty-four young adults read aloud a prose passage five times successively under 200 msec of bilateral DAF. Measures of the frequency of different types of disfluencies, locus of occurence of disfluencies in the speech sample, adaptation and consistency indicate that DAF-induced disfluencies are remarkably similar to those found in stuttering. It is suggested that DAF and stuttering disrupt speech at approximately the same “level” along the speech production process, possibly at the prosodic level.