A potential "tuning" role for the outer hair cells in children with language disorders

The cochlear outer hair cells serve a tuning function, and any dysfunction of their electromotile response can be reflected in language disorders. Otoacoustic emissions can be used to determine any dysfunction of these cells. A set of clinical records was established to register the neurological and auditory functioning in 42 children, followed by assessment with the Wechsler Intelligence Scale for Children (WISC), the Initial Language Test (ILT), the Auditory and Phonetic Discrimination Evaluation (APDE), tests for measuring Brainstem Auditory Evoked Potential (BAEP) and Transient Otoacoustic Emissions (TOAE). Subjects were classified into 3 groups in this study: Control (C; n = 20), Syntactic Phonological Disorder (SPD; n = 17), and those with Phonological Disability (PD; n = 5). BAEP studies showed a clear response when all children were stimulated to 20 dB. TOAE responses displayed clear and significant differences with half-octave band reproducibility for both ears, the largest effect being observed in the right ear. The results that were compared using ANOVA tests, showed that cochlear processing affects the brain language function, playing a critical role in the language phonetic process.