الفهرس 
Representation of Speech Sounds in the Auditory SystemOnly 14 pages are availabe for public view
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Abstract
Abstract: Review: Speech-Evoked Auditory responses can represent neural activity generated at different levels along the auditory pathway.
Purpose: To standardize speech evoked ABR and mismatch negativity in normal children of different age groups then apply speech evoked ABR and mismatch negativity in children with specific language impairment and central auditory processing disorders and study the effect of remediation programs on both tests.
Materials and methods: The control group comprised 45 children with normal peripheral hearing and normal central auditory processing and age range from 2 to 12 years. Specific language impairment group (SLI) which comprised 24 children with age range from 2 to 5 years. Central auditory processing disorders group {(C)APD} which comprised 34 children with age range from 5 to 12 years. All subjects were submitted to full history taking, otologic examination, Basic Audiological Evaluation, speech-ABR & MMN. Language evaluation was performed for SLI children and central auditory behavioral tests was performed for (C)APD children before and after remediation.
Results: In normal children, latency of Speech ABR waves decreased with increasing age. On the other hand, no significant difference was present in amplitude or spectral analysis amplitude. Complete Speech ABR maturation was reached at the age of 7 years. MMN maturation was reached at the age of 5 years. Generally, Speech ABR abnormality was present in around 91.66% of children. Moreover, Seventy five percent of SLI children showed MMN abnormality. In (C)APD children. Mismatch Negativity abnormality was present in 50% of children. After 3 months of remediation of eighteen (C)APD children, there was significant subjective improvement at home and school (using questionnaire). Moreover, nearly 78% of remediated children improved in Psychophysical tests and there was significant decrease in wave V latency and increase in wave O amplitude. Regarding MMN, there was no significant change in any of response parameters.
Conclusions: Speech evoked potentials could be used for testing younger children who are too young to perform behavioral central test battery or those with delayed language development and following up of remediation effect.
Keywords: Speech Evoked Auditory brainstem response, Mismatch Negativity, SLI, (C)APD.