ABSTRACT
Stuttering is one of the most prevalent speech and language disorders. Etiology of stuttering has been surveyed from different aspects such as biological, developmental, environmental, emotional, learning and linguistic. Literature shows that word length and syllable structure as linguistic features may influence frequency of disfluency in this disorder. Therefore, the aim of this study was to determine the effect of non-word length and syllable structure on frequency of disfluency in adults with stuttering. This cross- sectional descriptive- analytic study was performed on 18 adults who stutter with the age ranged between 20 to 39 years. Disfluency frequency was evaluated by asking the subjects to read a list contained 24 non- words. The non-words were selected based on word length [two and five syllables] and syllable structure [simple and difficult]. The obtained data were statistically analyzed through paired t-test using SPSS statistical software. The results showed that there was a significant difference between the frequency of disfluency in two and five syllable groups of non-words list [p=0.000]. There was a significant difference in the frequency of disfluency between simple and difficult syllable structure in two and five syllable groups of non- words list [p=0.000]. The findings of this study indicate that speech motor system performance in adults who stutter is affected by certain linguistic features such as word length and syllable structure