الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
A complex signal with known spectral and temporal characteristics is transduced and transcribed with high reliability in the normal cochlea and subsequently to the brainstem auditory pathways. The speech ABR recorded using speech syllables has been thoroughly studied in normal children as well as in other clinical populations as learning impaired. Therefore speech ABR is a good vehicle to study such physiology in CI subjects to ensure high fidelity transmission of the speech signal to the auditory brainstem.The speech ABR response characteristics in cochlear implantees may vary according to degree of neuronal survival and the depth of electrode insertion. Creating a model for the incomplete electrode insertion (which affects low frequency stimulation) and diminished neuronal survival (which predominantly occurs in the high frequency region) can predict the effects of these two conditions on speech ABR morphology in cochlear implantees and consequently their influence on the type of signal reaching the higher cortical areas.
The goal of this study was to create templates of electrophysiological performance to acoustic speech evoked auditory response in patients with cochlear implants. Speech evoked auditory response measures as well as other study variables were correlated to each other. These variables included demographic data, T and C electrical stimulation levels in final maps, aided free field thresholds, ECAP thresholds and post operative CT scan measurements.Also the effects of incomplete insertion of the electrode array and diminished neuronal survival, simulated using partial maps, were studied.
The study was carried out on ten cochlear implant cases between the ages of 5-10 years who were implanted since 2011 till 2014. These children attended the audiology unit at Alexandria Main University Hospital for follow up of programming and/or follow up of their devices. The second group (control group) consisted of three control subjects with normal hearing. The inclusion criteria for CI subjects were.