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.