Novel applications of objective measures in cochlear implants

Abstract

The treatment of severe to profound sensorineural hearing loss has rapidly evolved in the last several decades. The cochlear implant (CI) device, which forms an interface between a sound signal and the auditory nerve fibers (ANFs) of the deaf ear, is by now an accepted approach of rehabilitation for profoundly deaf individuals and generally achieves high performance in terms of speech perception. However, effectiveness still widely varies from person to person. Therefore, there is a continued impetus for further progress in CIs. In this thesis, we developed new applications of objective measures in modern CIs regarding electrically evoked compound action potential (eCAP) recording and electrical field imaging (EFI). With the development of an iterative deconvolution model, this thesis focuses on extracting the temporal firing properties of excited ANFs in human eCAP and evaluating their potential implications for clinical practice. In addition, this thesis describes an attempt to intra-operatively assess the placement of the electrode array within the cochlea based on impedance measurements.