Neurobiologic responses to speech in noise in children with learning problems: deficits and strategies for improvement

Objectives: Some children with learning problems (LP) experience speech-sou nd perception deficits that worsen in background noise. The first goal was to determine whether these impairments are associated with abnormal neuroph ysiologic representation of speech features in noise reflected at brain-ste m and cortical levels. The second goal was to examine the perceptual and ne urophysiological benefits provided to an impaired system by acoustic cue en hancements. Methods: Behavioral speech perception measures (just noticeable difference scores), auditory brain-stem responses, frequency-following responses and c ortical-evoked potentials (P1, N1, P1', N1') were studied in a group of LP children. Results: We report abnormalities in the fundamental sensory representation of sound at brain-stem and cortical levels in the LP children when speech s ounds were presented in noise, but not in quiet. Specifically, the neurophy siologic responses from these LP children displayed a different spectral pa ttern and lacked precision in the neural representation of key stimulus fea tures. Cue enhancement benefited both behavioral and neurophysiological res ponses. Conclusions: Overall, these findings contribute to our understanding of the preconscious biological processes underlying perception deficits and may a ssist in the design of effective intervention strategies. (C) 2001 Elsevier Science ireland Ltd. All rights reserved.