Middle Eastern Journal of Disability Studies

Background and Objective: Various studies have shown that there is a difference in phonological working–memory function between stuttering people and healthy. Many studies have shown that working memory capacity can be improved through education. Different studies have done on clinical populations with working memory deficiencies, their results have shown that impact of training on the performance of speech and language is undeniable. It is important consider the deficiencies of working memory as a factor that impact on speech, language and its effect on stuttering improvement. On the other hand, previous studies have shown effect of working memory deficiency on people with stuttering but few studies have ever addressed about the effect of improved status of working memory in stuttering. There is a lack of specific information regarding to the treatment of stuttering in school–age children. Therefore, the present study was to determine the effectiveness of non–word repetition on stuttering severity of stuttered school–age children. 
Methods: A total of 5 stuttered school–age children from waiting lists of different speech therapy clinics were participated in this single subject study. After determining their baseline status and measuring their stuttering severity (stuttering severity was determined based on the syllable stuttered percentage for each session and the curve of the baseline was drawn) and finally, children entered into the intervention program. For determining the baseline status, a series of supplementary evaluations were performed before the treatment. Supplementary evaluations were performed just before and after the treatment; as follows, (a) measurement of the syllable stuttered percentage according to unplanned telephone call, (b) performing non-word repetition test by Bakhtiar et al., and (c) severity rating (SR) test by families. Finally, the children entered into the treatment program and received 18 individual treatment sessions on non-word training. Variations of stuttering severity were systematically measured and documented during and after conducting treatment protocol. The research tool was the non-word repetition protocol.
Results: Data analysis showed that participants recorded a statistically significant change (p<0.05) and decline in percentage of syllables stuttered and severity stuttering, following the intervention. Based on the study findings, children's performance was stable at the baseline, following the treatment, the participants showed reduced percentage of syllables stuttered. PND indicators suggested that the intervention was effective for a participant to 100% certainty. The effectiveness of treatment was 80% in participants 3 and 4 and 50% in participants 2 and 5. According to Cohen’s d indicators, the effect of treatment was high in all 4 participants. According to the pre–post assessments, the usual stuttering severity, worst stuttering severity and SS % decreased in participants after the treatment, compared to before and only in the participant 5 did the usual stuttering severity remain unchanged before and after the study.
Conclusion: The results from this study showed that an intervention of non-word repetition statistically eventuated in decreases of the severity of stuttering in children participated in this study; consequently, these results provide the preliminary evidence that supports the usage of a non-word intervention as a complementary treatment approach by another treatment approach in children who stutter. However, significantly reduce the severity of stuttering is debatable.