Effects of alterations in auditory feedback on stuttering frequency during fast and normal speech rates

Abstract

That stuttering is ameliorated under altered auditory feedback conditions (e.g., masking and delayed auditory feedback) has been known for over 40 years. While this effect was initially attributed to auditory factors, more recent explanations have suggested that a change in speech production, specifically slowed speed rate is responsible. The purpose of this study was to determine if stutterers could demonstrate fluency enhancement under various altered auditory feedback conditions at normal and fast speech rates. Using these rates, stutterers read eight 300-syllable passages under nonaltered auditory feedback (NAF), delayed auditory feedback (DAF), frequency-altered feedback (FAF), and a combination of DAF and FAF (DAF+FAF). Results showed that stutterers significantly reduced stuttering under all altered auditory conditions at both speech rates. These results indicate that a slowed speech rate is not necessary to achieve fluency enhancement under altered auditory conditions. Because sensory and motor events are inseparable components within the speech process, it is proposed that reduction in stuttering occurs as a result of alterations to both auditory feedback and speech production. [Work supported by NIH-DC-00201 awarded to Haskins Laboratories.]