The relationship between early literacy skills and speech-sound production in students with intellectual disability and communication difficulties: a cross-sectional study.

Earlier research and reports from educational practice seem to suggest that teaching early literacy skills may facilitate speech-sound production in students with intellectual disabilities, but further research is needed to confirm a potential connection. This study investigated (1) the relationship between speech-sound production, phonological awareness, and letter-sound knowledge in students with intellectual disabilities and communication difficulties, and (2) to what degree phonological awareness and letter-sound knowledge explain the variance in speech-sound production over and above IQ and chronological age. A group of 116 students, aged 7-21, enrolled in Swedish compulsory schools for students with intellectual disabilities participated in this study. All had limited reading skills. The test results for phonological awareness, letter-sound knowledge, and speech-sound production had a wide range. The results showed that early literacy skills were moderately and significantly correlated with speech-sound production. After controlling for IQ and age in a regression model, the addition of phonological awareness and letter-sound knowledge explained 29% of the variance in speech-sound production. The results suggest that phonological awareness and letter-sound knowledge is associated with speech-sound production and that these associations are not explained by age or IQ. Further research on this group of students should aim to determine causal relationships, for instance, by investigating early reading intervention and the potential effect on speech-sound production.