Cochlear implants are a type of hearing device that can restore hearing in patients with severe hearing loss or deafness.
It comes in two main parts. The first part is an electrode array surgically placed into the inner ear and a magnet placed under the scalp. The surgery typically takes 1-2 hours under general anesthesia.
“Although we are sometimes able to preserve the remaining hearing in the implanted ear, residual hearing commonly declines after the surgery and that is one reason why you need to have a significant amount of hearing loss to benefit from a cochlear implant,” said Dr. Joshua Smith, ear, nose and throat specialist with Marshfield Clinic Health System.
The second part is an external processor that looks something like a hearing aid. It takes sound and transmits it to the internal receiver. This segment attaches to your head via the magnet that was placed under your scalp. This external part may be replaced in the future as updates are made available or in case the processor is broken.
More advanced testing
There are strict requirements regarding how much hearing loss you must have in order to qualify for cochlear implantation.
Hearing loss is first evaluated with a screening hearing test called an audiogram. If your hearing is poor, you may go on to additional testing to obtain a more complete picture of inner ear function. This may include a CT or MRI of the inner ear and testing of inner ear balance function.
During additional testing, your doctor puts you into real world scenarios such as repeating sentences that are read to you in the presence of background noise.
Hearing with implants is different
Once a cochlear implant is activated, it may take some time for your brain to hear and understand the new electrical sound.
“I think people have this popular notion that once they get the implant, their hearing will go back to the way it used to be,” said Smith.
For some, it can take several months before the sound becomes more natural and useful. That is because the electronic hearing from the cochlear implant is different from the acoustic hearing you were born with.
“Some patients say that when the implant is first turned on, it sounds like Mickey Mouse or Donald Duck,” Smith said. “However, this tends to fade into a more natural sound over time.”
Your doctor may use sounds you recognize, like a song, to help your brain hear and understand the sound. Sometimes patients are able to hear a sound the same way because their brain remembers what it sounds like.
How it looks
Since a cochlear implant is a device that is visible, some people have cosmetic concerns.
“The part that goes behind the ear isn’t really much bigger than some hearing aids,” said Smith.
Cochlear implants can match the color of your hair, so it is less noticeable.
While some have concerns about how a cochlear implant looks, Smith says it is transformative for those that have lost their hearing. Some people begin socially isolating themselves when their hearing becomes progressively worse.
“The world is silent and it can be like waking back up again,” Smith said. “The more hearing you can get the earlier in hearing loss, the better people do.”
Improving hearing may actually have health benefits that we do not yet fully understand. For instance, some research suggests that improved hearing can have positive effects on memory and may even slow onset or progress in some forms of dementia.
To learn more about cochlear implants, talk to your doctor.