The relationship between speech perception, speech production, and vocabulary abilities in children : insights from by-group and continuous analyses

Purpose: The purpose of this study was to explore the relationship between speech perception, speech production, and vocabulary abilities in children with and without speech sound disorders (SSDs), analyzing the data both by group and continuously.Method: Sixty-one Australian English-speaking children aged 48-69 months participated in this study. Children's speech production abilities ranged along the continuum from SSDs through to typical speech. Their vocabulary abilities ranged along the continuum from typical to above average ("lexically preco-cious"). Children completed routine speech and language assessments in addi-tion to an experimental Australian English lexical and phonetic judgment task. Results: When analyzing data by group, there was no significant difference between the speech perception ability of children with SSDs and that of chil-dren without SSDs. Children with above-average vocabularies had significantly better speech perception ability than children with average vocabularies. When analyzing data continuously, speech production and vocabulary were both sig-nificant positive predictors of variance in speech perception ability, both individ-ually in simple linear regression and when combined in multiple linear regres-sion. There was also a significant positive correlation between perception and production of two of the four target phonemes tested (i.e., /k/ and /?/) among children in the SSD group.Conclusions: Results from this study provide further insight into the complex relationship between speech perception, speech production, and vocabulary abilities in children. While there is a clinical and important need for categorical distinctions between SSDs and typically developing speech, findings further highlight the value of investigating speech production and vocabulary abilities continuously and categorically. By capturing the heterogeneity among children's speech production and vocabulary abilities, we can advance our understanding of SSDs in children