In the past two decades, the selection criteria for cochlear implantation have been greatly relaxed so that about 60-70% of present cochlear implant (CI) candidates have significant residual hearing in their contralateral ear. However, contralateral hearing is often not considered in rehabilitation programs, mainly due to the lack of scientific evidence on the role it may play. The present project aims to better understand the mechanisms of perceptual learning of CI-processed speech after implantation and to develop and test rehabilitation strategies for CI users.

Inclusion Criteria:

• Age>18
• Unilaterally postlingually-deafened adult cochlear implanted candidates (IC-Uni)
• Person with almost normal or moderate contralateral hearing ( under 60dB)
• Cochlear implanted person whose activation has not yet been performed
• Cochlear implanted subjects with bilateral post-lingual profound deafness, who already benefit from a unilateral cochlear implant and candidates to a bilateral cochlear implant
• Affiliated to social security

Exclusion Criteria:

• - Subjects under juridical protections or tutelage measure
• Subjects with associated neurological or neurodegenerative conditions
• Significant anatomical changes on CT scan of the temporal bone that may interfere with the insertion of the cochlear implant