Phonological short-term and working memory in 5- and 6-year-old children with speech sound disorders

Abstract

Objectives: The purpose of this study was to compare phonological short-term and working memory processes in children with speech sound disorders (SSD) and their typically developing (TD) peers. Additionally, the study aimed to explore the relationship among two memory functions, articulation and vocabulary abilities. Methods: Forty 5- and 6-year-old children enrolled: 20 children with SSD and 20 TD children. Children participated in three memory tasks, digit span forward, digit span backward, and nonword repetition. Results: In all tasks, significant differences were observed between SSD and TD groups, and between the 5- and 6-year-old age groups. According to task type and number of syllables, the performances of SSD and TD children were different in experimental tasks. Moreover, when the age was included as an independent variable of digit span tasks, another aspect of the differences between the groups was observed. In addition, the task performances were not correlated with the percentage of consonants correct, but instead showed a significant correlation with the receptive and expressive vocabulary in SSD and TD children. Conclusion: Phonological memory, especially phonological working memory, was weaker in SSD children in comparison to TD children. These results suggest that profound difficulties in phonological working memory are linked to persistent speech sound disorders. The theoretical and clinical implications are discussed about phonological memory and vocabulary acquisition in SSD children.