Correlation between speech perception and electrically-evoked auditory potentials measured in subjects with Auditory Neuropathy after cochlear implantation

Cochlear implantation is considered an effective management option for children diagnosed with auditory neuropathy. It is assumed that this is because, in most cases of auditory neuropathy, the lesion is located at the inner hair cells or the primary afferent synapse, rather than the auditory nerve per se. Previous studies reporting benefit in cochlear implantation in this population of subjects have assessed benefit using behavioural measures such as speech perception tests. In this study, we have assessed the benefit of cochlear implantation in subjects with AN using objective assessments including electrically-evoked auditory brainstem responses (ABR) and cortical auditory evoked potentials (CAEP) and have correlated this with subjective assessments of speech perception. Correlations between objective and subjective assessments demonstrate that the role of electrical stimulation in providing benefit is not simple. We show that there is no correlation between the electrically-evoked ABR and the electrically-evoked CAEP waveforms. Nor is there a correlation between the objective tests and speech perception abilities.