The Effects of Speech Sound Disorder on Vocabulary Development

Abstract

Objectives: The purpose of this study was to examine the role of speech sound disorders in the development of children’s vocabulary through longitudinal analysis. Methods: Three hundred and twenty-four 6-year-old children were assessed in severity groups with speech sound disorders (SSD: general level, a slight error, the recommendation for in-depth examination, and suspected speech sound disorder). This study examined whether the model of change in vocabulary (receptive, expressive) original score according to age (3, 5, and 7 years old) of four SSD groups was suitable for the Latent Growth Model. In addition, cross-analysis was used to examine whether there was a significant difference in the classification of receptive and expressive vocabulary development normality (abnormal, normal development, slight delay, and vocabulary development delay) according to age changes in the four groups. Results: Results found that the severity of SSD did not affect vocabulary development continuity, but had a significant effect on the classification of vocabulary development normality standards. The severity of SSD had a significant effect on the development delay of the 7-year-old receptive vocabulary and the development delay of the 3-year-old expressive vocabulary. Conclusion: It would be desirable to check the vocabulary development of children with SSD according to age, understanding that subjects with suspected SSD can show significant differences in expressive vocabulary at the age of 3 and receptive vocabulary development at the age of 7.