Brain Plasticity and Rehabilitation with a Cochlear Implant.

The functional changes that occur in the brain due to deafness may affect the way the auditory system processes sound after cochlear implantation. Brain plasticity plays a crucial role in the success of cochlear implantation to facilitate or develop spoken language in profoundly deaf individuals. The functional plasticity that occurs in postlingually deaf adults during periods of deafness can both support and hinder speech understanding with a cochlear implant, depending on the nature and degree of functional changes. Evidence so far suggests that the strategies people use to communicate while deaf may influence whether the functional changes are adaptive or maladaptive. In the case of children with congenital deafness, evidence is very strong for a sensitive period in which auditory input must be restored if subsequent oral language is to be developed successfully. Successful oral language use and speech understanding in individuals implanted after 7 years of age depends strongly on the pre-implant use of hearing aids and auditory-verbal communication. Future research should focus on how to harness our growing knowledge of brain plasticity to optimize the outcomes of cochlear implantation in each individual.