Linguistic factors associated with stuttering-like disfluencies in Japanese preschool and school-aged children who stutter

Introduction: Stuttering is influenced by different linguistic factors, such as sentence- and word- level factors. However, its developmental differences remain unclear. Thus, this study examined the developmental differences in the linguistic factors associated with stuttering-like disfluencies (SLD) among Japanese preschool and school-aged children who stutter. Methods: We analyzed utterances from 30 Japanese-speaking children who stutter aged 5-10 years. Participants were divided into three groups according to their age (5-6, 7-8, and 9-10 years old). Results: Significant effects of sentence length, bunsetsu length, syllable weight, and bi-mora frequency on SLD frequency were observed across the age groups. In contrast, there was not a significant effect of mora frequency on SLD frequency. Conclusions: Both sentence- and word-level factors affected SLD in children who stutter aged 5-10 years. Future research should be conducted with children below 5 years of age to observe detailed developmental differences in the linguistic factors that affect stuttering.