The modification of speech naturalness during rhythmic stimulation treatment of stuttering.

This study investigated the modification of speech naturalness during stuttering treatment. It systematically replicated an earlier study (Ingham & Onslow, 1985) that demonstrated that unnatural-sounding stutter-free speech could be shaped into more natural-sounding stutter-free speech by using regular feedback of speech-naturalness ratings during speaking tasks. In the present study, the some procedure was used with three persons who stutter-2 adolescent girls and 1 adult man-during rhythmic stimulation conditions. The two adolescent participants spoke only English, but Spanish was the first and English the second language (ESL) of the adult participant. For the 2 adolescents, it was demonstrated that their unnatural-sounding rhythmic speech could be shaped to levels found among normally fluent speakers without losing the fluency-inducing benefits of rhythmic speech. The findings indicate that speech-naturalness feedback may be a powerful procedure for overcoming a problematic aspect of rhythmic speech treatments of stuttering. However, it was not possible to deliver reliable speech-naturalness feedback to the adult ESL speaker, who also displayed a strong dialect. The study highlights the need to find strategies to improve interjudge agreement when using speech naturalness ratings with speakers who display a strong dialect.

Evaluation of a stuttering treatment based on reduction of short phonation intervals.

This paper reports the results of an efficacy study of a stuttering treatment program known as Modifying Phonation Intervals (MPI), which trains stuttering speakers to reduce the frequency of relatively short phonation intervals (PIs) during connected speech across speaking tasks and situations. Five young adult male stuttering speakers were treated in this computer-based program that systematically trains speakers to reduce selected short PIs found to functionally control stuttering. The treatment process was evaluated using multiple-baseline designs. Treatment was largely self-managed and based on a performance-contingent schedule of within-clinic speaking tasks (Establishment), beyond-clinic speaking tasks (Transfer), and systematic decreases in assessment occasions (Maintenance). Assessments were made at regular intervals before, during, and after treatment. All speakers achieved stutter-free and natural-sounding speech during within- and beyond-clinic speaking tasks at the completion of Maintenance. All were tested 12 months after completion of Maintenance, and all maintained the results. The findings from this study suggest that this procedure may make a significant contribution to stuttering treatment practice.