Using Electrocochleography During Cochlear Implantation of the Neuro Zti.

The main objective of this study is to evaluate the correspondence between eCochG and residual hearing by adding two modifications. First, a novel technique for placing and maintaining the probe in place during the whole insertion will be used. Second, a new metric for estimating the eCochG response will be evaluated (eCochG trauma index). The secondary objective is to find other markers of the cochlear trauma insertion associated to eCochG measures. This will be used to evaluate to which extend a traumatic insertion will be deleterious for the patient's post-operative hearing, and ultimately to prevent trauma to the inner ear. Finally, the potential differences in cochlear trauma resulting of the electrode array insertion from two different surgery techniques will be investigated; Either using a manual insertion or using a robotic arm that will drive the insertion automatically.

Main study procedures and assessments: * Visit 1 (D-30+/-14) INCLUSION: subject information/consent, inclusion/exclusion criteria, CT-scan, Tonal audiometry * Visit 2 (D0+/-14) COCHLEAR IMPLANT SURGERY: CT-scan, Intra-op eCochG, eCAP, Impedance * Visit 3 (D+30+/-14) FOLLOW-UP 1 MONTH: Tonal audiometry, Impedance, Fitting maps * Visit 4 (D+60+/-14) FOLLOW-UP 2 MONTH: Tonal audiometry, Impedance, Fitting maps, Phonemes * Visit 5 (D+90+/-14) FOLLOW-UP 3 MONTH: Tonal audiometry, Impedance, Fitting maps, Phonemes