![]() To examine potential auditory processing deficits in children with SLI, researchers have used a variety of methods, including temporal order judgment (TOJ) tasks, just noticeable difference (JND) tasks, phoneme identification tasks, and categorical perception tasks. Children who are less able to process acoustic or linguistic information will have more difficulty extracting statistical regularities from the input language, including word boundaries and form class, which will lead to difficulties at higher levels of language representation (e.g., Leonard, 1998). Whatever the underlying nature of the auditory or phonological processing difficulty, its effects on language acquisition would be profound. Finally, Stark and Heinz (1996a, 1996b) have argued that children with SLI have inadequately specified phonological representations in long-term memory. ![]() Gathercole and Baddeley (1990) have argued that children with SLI have reduced storage for phonological material in working memory. Leonard and colleagues have argued that children with SLI have a generalized slowing of sensory processing across modalities ( Leonard, 1998 Leonard, McGregor, & Allen, 1992 Miller, Kail, Leonard, & Tomblin, 2001). For example, Tallal and colleagues have argued that children with SLI have a deficit in processing rapidly changing auditory information ( Tallal & Piercy, 1973, 1974, 1975 Tallal, Stark, Kallman, & Mellits, 1981). The nature of these putative difficulties remains an open question, however. Although children with SLI are impaired in many aspects of language, including morphology and syntax, impairments in auditory processing have been hypothesized to be a possible underlying cause of language impairments (e.g., Eisenson, 1972). These children experience language learning difficulties despite having normal hearing and normal nonverbal intelligence with no obvious articulatory or neurological deficits ( Leonard, 1998). The purpose of the present investigation was to examine categorical perception of speech by children with specific language impairments (SLI). Further, poor performance on speech perception tasks may not be due to a speech perception deficit, but rather to a consequence of task demands. These data suggest that children with SLI perceive natural speech tokens comparably to age-matched controls when listening to words under conditions that minimize memory load. Children with SLI still discriminated phonemically contrastive pairs at levels significantly better than chance, with discrimination of same-label pairs at chance. There were no group differences for identification data, but children with SLI showed lower peak discrimination values. Both groups exhibited all hallmarks of categorical perception: a sharp labeling function, discontinuous discrimination performance, and discrimination predicted from identification. Children identified and discriminated digitally edited versions of naturally spoken real words in tasks designed to minimize memory requirements. In this study, 20 children with SLI (mean age = 9 years, 3 months) and 20 age-matched peers participated in a categorical perception task. These findings have come from studies in which perception of synthetic versions of meaningless syllables was typically examined in tasks with high memory demands. Previous research has suggested that children with specific language impairments (SLI) have deficits in basic speech perception abilities, and this may be an underlying source of their linguistic deficits.
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