Backward and Simultaneous Masking in Children With Grammatical Specific Language Impairment: No Simple Link Between Auditory and Language Abilities

Contact authors: Stuart Rosen, Speech, Hearing and Phonetic Sciences, University College London, 2 Wakefield Street, London WC1N 1PF, England. E-mail: stuart{at}phon.ucl.ac.uk . Purpose: We investigated claims that specific language impairment (SLI) typically arises from nonspeech auditory deficits by measuring tone-in-noise thresholds in a relatively homogeneous SLI subgroup exhibiting a primary deficit restricted to grammar (Grammatical[G]-SLI). Method: Fourteen children (mostly teenagers) with G-SLI were compared to age-, vocabulary-, and grammar-matched control children on their abilities to detect a brief tone in quiet and in the presence of a masking noise. The tone occurred either simultaneously with the noise or just preceding it (backward masking). Maskers with and without a spectral notch allowed estimates of frequency selectivity. Results: Group thresholds for the G-SLI children were never worse than those obtained for younger controls but were higher in both backward and simultaneous masking than in age-matched controls. However, more than half of the G-SLI group (8/14) were within age-appropriate limits for all thresholds. Frequency selectivity in the G-SLI group was normal. Within control and G-SLI groups, no threshold correlated with measures of vocabulary, grammar, or phonology. Nor did the language deficit in the G-SLI children vary with the presence or absence of auditory deficits. Conclusion: The auditory processing deficits sometimes found in children with SLI appear unlikely to cause or maintain the language impairment. KEY WORDS: specific language impairment, auditory processing disorder, masking, backward masking, simultaneous masking CiteULike Connotea Del.icio.us Digg Facebook Reddit Technorati Twitter What's this?