The purpose of this study is to compare two methods of cochlear implantation : conventional manual insertion versus robot-assisted in order to verify whether robotic insertion provides better performance in the noisy environment.

To do this, we will compare the two methods of insertion of the electrode holder, on 140 patients candidates for cochlear implantation randomized in two groups (70 conventional surgery versus 70 robot-assisted surgery). All patients will be recruited during 17 months, in our Ear, nose and throat (ENT) Department of the Pitié-Salpêtrière hospital group, the first center for adult patients established in France (on average 180 patients/year).

Patient will be followed for 9 months with clinical evaluation, imaging, audiometric, listening effort and quality of life assessments. These evaluations will be carried out preoperatively and postoperatively at 3 months and 6 months post-activation of the cochlear implant.

In the case of severe (70 to 90dB loss) and profound (>90dB loss) hearing loss, when conventional hearing aids no longer provide sufficient benefit, cochlear implantation remains the only possible solution for hearing rehabilitation. In implanted patients, a clear improvement in communication in silence is observed, but almost all patients have difficulty understanding speech in noisy environments. Cochlear implantation involves inserting an electrode holder into the cochlea during a surgical procedure under general anesthesia. The insertion of the electrode holder must be as minimally traumatic as possible in order to preserve the cochlear structures and avoid post-operative fibrosis that could impact the auditory outcomes.

The conventional method of this surgery is the manual insertion of the electrode holder. In recent years, robotic assistance, the RobOtol®, has been developed with the aim of avoiding the jerks of the surgeon's hand and improving the precision of the insertion. RobOtol® has had its CE marking since 2016 and is used in several hospitals in France and abroad.

Inclusion Criteria:

• Adult patient ≥ 18 years old
• Patients with an indication for uni or bilateral, simultaneous or sequential cochlear implantation: severe to profound bilateral deafness with intelligibility ≤70% for Fournier dissyllabic words, in free field, at 60dB with adapted hearing aids.
• Patient able to understand the information note and give written consent
• Affiliation to a French social security system

Exclusion Criteria:

• Patient who does not speak French
• Etiologies of deafness known to be of bad prognosis (auditory neuropathy, congenital profound deafness, immediate post-meningitis profound deafness, vestibular schwannoma on the side of the ear to be implanted)
• Impossibility of testing the effect of the cochlear implant alone on hearing results (cochlear implantation in the context of unilateral deafness or fluctuating deafness)
• Cochlear implantation requiring the use of a perimodiolar electrode holder.
• Pregnant and breastfeeding women
• Patients wearing electronic devices, in direct connection with the brain or nervous system
• Patient included in another interventional study (Jardé 1)
• Patient under legal protection (guardianship or curatorship) or deprived of liberty

The procedures carried out with the French data privacy authority (CNIL, Commission nationale de l'informatique et des libertés) do not provide for the transmission of the database, nor do the information and consent documents signed by the patients. Consultation by the editorial board or interested researchers of individual participant data that underlie the results reported in the article after deidentification may nevertheless be considered, subject to prior determination of the terms and conditions of such consultation and in respect for compliance with the applicable regulations.

Beginning 3 months and ending 3 years following article publication. Requests out of these time frame can also be submitted to the sponsor

Researchers who provide a methodologically sound proposal.