In the past few years, thousands of people with profound or severe hearing loss have received cochlear implants. These devices offer a way to give the sensation of sound to people who have damage to the inner part of the ear.
People who have sensorineural hearing loss are the ones that can benefit from implants. Inside the inner ear is a structure known as the cochlea. This structure is home to millions of hairs, known as stereocilia, that send sound to the auditory nerve as electrical signals. When these hairs receive a damage or do not develop properly, the ear cannot transmit those signals.
How Do Cochlear Implants Work?
The implants are part of a system that transmits sound to the auditory nerve.
On the outside sits the microphone, speech processor, and transmitter. The implant includes a receiver and electrodes.
The microphone picks up the sound and sends it to the processor. The processor turns the sound into electrical impulses that it sends to the transmitter. The transmitter broadcasts the impulses to the receiver implanted behind the ear. The receiver passes the signals to the electrodes implanted in the cochlea. That is where they transfer to the auditory nerve as sound signals.
These implants do not cure deafness, but they do offer a way to receive sound signals otherwise not heard.
Who Would Benefit from Implants?
Both adults and children can benefit from implants under particular circumstances. The ideal candidates, whether adult or child, will have profound hearing loss on both sides and get little benefit from the use of hearing aids.
Adults must have lost their hearing after developing speech and language skills. They also need to have the desire to be part of the hearing world and commit to the work required to learn how to use the implants.
When possible, due to age or ability, children need to be a full participant in the decision to have implants. They need to understand the benefits and limitations of technology. They need to commit to the rehabilitation and education programs required to use the implants to their maximum extent.
What Happens During the Implant Procedure?
The surgery itself involves implanting the receiver behind the ear and placing the sensors in the cochlea. The doctor may do it as an outpatient procedure or may require the patient to do an overnight stay in the hospital.
About a month or so later, after everything has healed, the next step is fitting for the external parts. At this time, the audiologist will also program and activate the implant. It is at this point the first sounds should transmit through the implant to the auditory nerve.
Several fittings and adjustments will be needed to tune the implant and to improve its reception. This coincides with the patient doing work with audiologists, speech therapists, and other professionals to improve speech and learn how to respond to the sounds coming through the implant.
Cochlear implants can make a significant difference in the life of an adult or child who receives them. They are not a magic wand that will instantly restore hearing. However, they can make living in the hearing world much easier.