Post-treatment speech naturalness of Comprehensive Stuttering Program clients and differences in ratings among listener groups

Abstract

The purposes of this study were to investigate naturalness of the post-treatment speech of Comprehensive Stuttering Program (CSP) clients and differences in naturalness ratings by three listener groups. Listeners were 21 student speech-language pathologists, 9 community members, and 15 listeners who stutter. Listeners rated perceptually fluent speech samples of CSP clients obtained immediately post-treatment (Post) and at 5 years follow-up (F5), and speech samples of matched typically fluent (TF) speakers. A 9-point interval rating scale was used. A 3 (listener group)x2 (time)x2 (speaker) mixed ANOVA was used to test for differences among mean ratings. The difference between CSP Post and F5 mean ratings was statistically significant. The F5 mean rating was within the range reported for typically fluent speakers. Student speech-language pathologists were found to be less critical than community members and listeners who stutter in rating naturalness; however, there were no significant differences in ratings made by community members and listeners who stutter. Results indicate that the naturalness of post-treatment speech of CSP clients improves in the post-treatment period and that it is possible for clients to achieve levels of naturalness that appear to be acceptable to adults who stutter and that are within the range of naturalness ratings given to typically fluent speakers. Readers will be able to (a) summarize key findings of studies that have investigated naturalness ratings, and (b) interpret the naturalness ratings of Comprehensive Stuttering Program speaker samples and the ratings made by the three listener groups in this study.