Profound deafness rehabilitation by uni-or bilateral cochlear implantation in post-lingual deaf adults

Djourno and Eyries showed in 1957 that electric stimulations, provided to the cochlea, created auditory responses to a profoundly deaf patient. In 1976, CH Chouard performed the first multi-channel implantation reestablishing speech comprehension. Since, major technical findings allowed auditory restoration with high device reliability and efficient oral communication thanks to improved signal processing strategies. More than 200 000 profoundly deaf patients were implanted worldwide. In France where cochlear implantation is supervised by la Haute Autorite de sante, about 800 candidates are operated on each year. Surgical procedure is well codified in centers performing from 50 to more than 100 implantations per year, like in our center. After unilateral cochlear implantation, speech performance is satisfactory in silent environment. In noisy environment, outcome is clearly enhanced by bilateral cochlear implantation, yielding professional reinsertion and enhanced life quality. Bilateral cochlear implantation may be performed simultaneously when cochlear ossification is suspected, e.g. after bacterial meningitis. Profound deafness rehabilitation may be proposed to palliate the handicap it creates as soon as intelligibility collapses on one side and if comprehension is limited on the other side despite hearing head, thus restoring oral communication in noisy environment.