Assessment of aided language comprehension and use in children and adolescents with severe speech and motor impairments.

There is limited knowledge about aided language comprehension and use in children who use aided communication and who are considered to have a relatively good comprehension of spoken language. This study's purpose was to assess their aided language skills. The participants were 96 children and adolescents who used communication aids (aided group) and 73 children and adolescents with natural speech (reference group), aged 5 to 15 years. All of the participants who used aided communication were regarded by their teachers or professionals as having age-appropriate language comprehension. All of the participants completed (a) standardized tests of visual perception, non-verbal reasoning, and comprehension of spoken language, and (b) tasks designed for this study that measured comprehension and production of graphic utterances through communicative problem solving. Using their own communication systems, the participants achieved an average of 72% correct on the graphic symbol comprehension task items, and 63% on the expressive tasks. The participants with natural speech achieved an average of 88% correct on comprehension items, and 93-96% accuracy on production items. The differences between groups were significant on all the tasks and standardized tests. There was considerable variation within the group of participants who used aided communication, and the results reveal a need to develop instruments with norms for aided language competence that can inform the implementation of interventions to support aided language development.