Providing the Non-Word Repetition test and determining its validity and reliability and comparing phonological working memory in 4 to 6 Farsi-speaking normal and SSD children in Tehran City

Abstract Introduction: Speech Sound Disorders (SSD) is a common childhood disorder characterized by developmentally inappropriate errors in speech production that can reduce intelligibility. Some data suggests that a deficit in phonological working memory may contribute to the disorder. Phonological working memory as a part of the working memory system which is responsible for coding and storage of phonological information. Many researchers have employed Non-Word Repetition (NWR) to measure phonological working memory. The aim of this study was to providing a Non-Word Repetition test and determining its validity and reliability and explore differences the phonological working memory in 4 to 6 years old Farsi-speaking normal and SSD children. Material and Methods: The participants in this study were 32 SSD children and 32 normal children-matched for age and sex- as a control group. Phonological working memory was examined in both groups with NWR task. For this purpose, NWR task was designed, and after determining its validity and reliability, was employed in both groups. Mann-Whitney U Test was conducted to examine the differences in mean scores in NWR task. Results: 25 non-words in this test, has content validity. Coefficient correlation between consecutive performances was obtained .997 (P<.001). Mean scores in SSD children compared with the control group was lower and results of statistical test revealed that the children’s ability to repeat non-words in normal and SSD group are significantly different (P<.001). Conclusion: Non-word Repetition test showed high validity and reliability. Weaker performance of the SSD children in NWR task could be due to a weakness in hold novel sound sequences in phonological working memory presumably doesn’t allow stable long-term phonological representations to be established. In the absence of known etiological factors, a deficit in phonological working memory may consider as a cause of SSD in children. Key words: Speech Sound Disorders (SSD), phonological working memory, Non-Word Repetition (NWR) test, validity, reliabilit