title: The perception of speech naturalness of post-therapeutic and altered auditory feedback speech of adults with mild and severe stuttering.
abstract: The effect of therapy and altered auditory feedback (AAF) on the perception of speech naturalness of people who stutter was examined. Thirty-five naive young adult listeners rated speech samples from fluent speakers and individuals who stutter. Samples came from normal adults who spoke Standard American English; adults with mild or severe stuttering who spoke under conditions of non-altered feedback (NAF), delayed auditory feedback (DAF), and frequency-altered feedback (FAF); and adults with mild or severe stuttering prior to and following successful completion of a Precision Fluency Shaping Program. Speech produced under AAF was rated as significantly more natural sounding than speech from the same individuals under NAF (p < 0.0001). Speech produced during FAF was judged to be more natural sounding than that produced during DAF for those with mild (p = 0.003) and severe (p < 0.0001) stuttering. Mild stuttered speech was judged to have more natural-sounding speech than severe stuttered speech during AAF (p < 0.0001). Speech from individuals following therapy was rated significantly less natural sounding than that from individuals during AAF for both mild and severe stuttering (p < 0.0001). The speech of individuals prior to therapy was rated significantly more natural than their speech produced after therapy (p < 0.0001). Speech from normal fluent speakers was rated as significantly more natural sounding than all samples produced from the individuals who stutter (p < 0.0001). These findings support the contention that AAF benefits those who stutter through a reduction of stuttering with a gain in perceived speech naturalness.
authors.affiliation: Department of Communication Sciences and Disorders, East Carolina University, Greenville, NC 27858-4353, USA. stuarta@mail.ecu.edu
authors.forename: Andrew
authors.initials: A
authors.lastname: Stuart
authors.forename: Joseph
authors.initials: J
authors.lastname: Kalinowski
mesh_terms: D000328:Adult; D001676:Biofeedback, Psychology / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D015588:Observer Variation; D013067:Speech Perception; D013070:Speech Therapy; D013342:Stuttering / Q000628:therapy*; D016896:Treatment Outcome; D014831:Voice