If youre hoping that a cochlear implant will restore hearing, youre in for a disappointment. Although an implant can create a simulacrum of hearing by providing a representation of sounds and can make it possible for a hearing impaired person to understand speech, it is far and away not the same as restoring hearing. So how does it work?
The hardware
The implant consists of two parts, one implanted into the ear and the other part worn outside the ear. For such a small device, it contains quite a lot of components. Theres a microphone that gathers the sounds, a speech processor that decides which sounds are relevant and how they should be put together and a transmitter that converts signals from the processor into impulses that can be transmitted to the electrode array that passes them on to the nervous system. The receiver and electrodes are the parts that are actually implanted under the skin.
Who can it help?
A cochlear implant cant be used in all cases of hearing loss. If, for example, the auditory nerve has been affected, the cochlear implant will not be able to transmit impulses to the brain. There are several other factors that are taken into account.
If an adult patient has good verbal communication skills, but cant hear, they may be a candidate for an implant. In small children, doctors want to see some form of commitment to hearing therapy on the part of the parents. In general, doctors will avoid surgery if less invasive techniques such as an ordinary hearing aid might work well.
Even in adults, simply installing an implant wont work unless the patient has access to therapists that can guide them through the post-operative rehabilitation process. As a result, it could be said that getting an implant is only the beginning of a much longer journey that requires professional and personal support after the initial surgery.
Whats the success rate?
Speak to your doctor to find out what the chances are in any specific case. Results are very variable with some patients experiencing much improved hearing, some not noticing much difference and rare cases in which the implant seems to cause reduced residual hearing. Because of these mixed results, most doctors will recommend a single cochlear implant, leaving the other ear untreated in case a better solution is found in the future. However, some researchers have found that bilateral implants resulted in better hearing and faster development in hearing impaired children.
What is the medical procedure like?
Youll have to go through a thorough screening process in order to determine whether the chances of a cochlear implant working in your case are sufficient to warrant attempting the surgery. Once you have full approval, youre ready for your op. This will be done under full or local anesthetic and theres a chance you may have to spend the night in hospital.
Four to six weeks later, youll return for the external components of your implant. Now you will go through a process in which experts activate and calibrate the components. Dont expect everything to be working perfectly after the first visit. Some patients have to return several times during a period that spans several months.