Inner ear implants
An inner ear implant, or cochlear implant (CI) is an electronic device surgically implanted in the inner ear of a profoundly or completely deaf individual.
Unlike hearing aids, the cochlear implant does not make sounds louder or clearer. Instead, it stimulates the hearing nerve directly. A cochlear implant gives the hearing impaired recipient a sensation of hearing. It is important to understand that it provides a reduced sense of hearing, only, not a fully restored hearing.
An inner ear implant is comprised of internal and external components. The microphone and speech processor are the external components, with the microphone located on the ear and the processor placed immediately behind the ear. The processor is fixed onto the transmitter implanted beneath the skin.
Another internal component is the decoder placed in the inner ear.
Sounds transmitted directly to inner ear
A cochlear implant takes over the function of the damaged cochlear in the ear, in which some of the vital hair cells are missing. The implant converts speech and surrounding sounds into electrical signals and sends these signals to the hearing nerve in the inner ear. On their way, the signals pass the damaged part of the hearing system. These signals are recognised as sounds by the brain.
Approximately one month after surgery the speech processor is connected and the user will begin to perceive sound. The last part of the implant process is rehabilitation during which the patient receives auditory training and learns different communication techniques. It takes time, practice and patience to learn how to use a cochlea implant.
Quality of life improved
An implant does not cure deafness, but can nevertheless be very helpful. The benefits will vary from one person to another. However, after some time, about 50 per cent of the patients are able to manage a normal job and only experience few problems - such as listening in noise. 80 per cent will be able to conduct a telephone conversation. Many patients also find that their overall quality of life improves after the implantation.
Children and cochlear implants
Many children may also benefit significantly from cochlea implants. The child's young age and communication skills prior to implantation are important factors for a successful outcome.
Electric acoustic stimulation
Some users may benefit from an electric acoustic stimulation (EAS), which is the use of a hearing aid and a cochlea implant together in the same ear. The hearing aid acoustically amplifies low frequencies, while the cochlear implant electrically stimulates the middle and high frequencies. The inner ear processes acoustic and electric stimuli simultaneously.
Results of international studies have shown a highly synergistic effect between hearing aid and cochlear implant technology, particularly evident in speech understanding in noise, pitch discrimination and music appreciation.
Source: The figures in this article are quoted from ENT News, www.cochlearimplant.dk