Sound discrimination and explicit mapping of sounds to meanings in preschoolers with and without developmental language disorder

To investigate links between sound discrimination and explicit sound-meaning mapping by preschoolers with and without developmental language disorder (DLD).

We tested 26 children with DLD and 26 age- and gender-matched peers with typical language development (TLD). Inclusion was determined via results of standardised assessments of language and cognitive skills and a hearing screening. Children completed two computerised tasks designed to assess pitch and duration discrimination and explicit mapping of pitch- and duration-contrasting sounds to objects.

Children with TLD more successfully mapped pitch categories to meanings than children with DLD. Children with TLD also showed significantly better overall sound discrimination than children with DLD. Sound-discrimination scores were marginally associated with overall sound-meaning mapping in multivariate analyses of covariance (MANCOVAs). Correlation tests indicated significant associations between discrimination and mapping, with moderate to large effect sizes. Thus, significant sound-discrimination differences between the groups may contribute to differences in sound-meaning-mapping accuracy.

Children with DLD had more difficulty mapping sound categories to meanings than TLD peers. We discuss possible explanations for this finding and implications for theoretical accounts of the aetiology of DLD.