Electrocochleography Along Cochlear Implant Auditory Rehabilitation

Electrocochleography (eCochG) is an electrophysiological measurement to evaluate the activity of cochlear hair cells in response to acoustic stimulation. This measure thus reflects the functional state of the cochlea and more specifically the neuronal survival. Whereas in the normal-hearing subject, eCochG collection requires the introduction of a collection electrode in the middle ear, closest to the cochlea, in the cochlear implant subject, eCochG can be collected through the electrodes of the cochlear implant. Measured during surgery, eCochGs may help optimize the placement of the electrode array within the cochlea and help in the decision to refer the patient to a conventional cochlear implant or, when residual cochlear activity is detected, to an electro-acoustic implant system. The main objective of this study is to evaluate the usefulness of intra-operative eCochG collections for the optimization of electrode array placement within the cochlea and then for monitoring the residual hearing and its relationship to hearing performance during the first months of rehabilitation.