Auditory processing in dyslexia and specific language impairment: is there a deficit? What is its nature? Does it explain anything?

There is much controversy about the extent to which auditory processing deficits are important in the genesis of language disorders, particularly specific language impairment (SLI) and dyslexia (or specific reading disability—SRD). A review of the available literature reveals that some but not all auditory skills are impaired, on average, in groups of SLI/SRD listeners. Typically only a minority of SLI/SRD listeners exhibit any auditory deficits, and there is little or no relationship between the severity of the auditory and language deficits in SLI/SRD groups. Control groups sometimes exhibit stronger relationships of this type. It is not yet clear why some auditory skills but not others differentiate the two groups, but the claim that the deficit is specific to rapid temporal processing is almost certainly wrong. Nor is the deficit specific to speech sounds. Nonverbal intelligence must be accounted for in any exploration of the relationship between auditory and language/literacy skills. No clear relationships between nonspeech and speech deficits have yet been demonstrated. Thus auditory deficits appear not to be causally related to language disorders, but only occur in association with them. r 2003 Elsevier Ltd. All rights reserved.