Hearing aids are a marvel of modern medical technology, enabling about 35 million Americans who have measureable hearing loss to get some normalcy back in their lives. However, hearing aids can’t help everyone; those who are deaf or severely hard of hearing may have to find a different solution.
Enter cochlear implants.
Hearing Aids vs. Cochlear Implants: What’s the Difference?
Cochlear implants and hearing aids both help people who can’t hear well, but that’s where the similarities end. Hearing aids amplify sound (and newer models are capable of so much more). Cochlear implants are different.
Instead of making sounds louder, cochlear implants work directly on the nerve that carries sound to the brain. They allow sound to bypass a damaged cochlea, a structure in the inner ear that converts sound vibrations into electrical impulses for the auditory nerve to send to the brain.
How Do Cochlear Implants Work?
Unlike a hearing aid, a cochlear implant is not an in-ear device. Instead, it has multiple components:
- The microphone is a structure that sits behind the ear and looks somewhat like a hearing aid. There is also an all in one devices that does not sit behind the ear at all. Its job is to pick up sound from the environment.
- The microphone sends sound to the speech processor, which selects and arranges the sound and turns it into a digital signal.
- The speech processor passes the signal to the transmitter, an external structure that looks like a disc attached to the skull. The transmitter then sends the signal to the receiver, which is located under the skin but attached to the transmitter with a magnet.
- The receiver picks up the signal and passes it along to an electrode array in the cochlea, which sends the signal to the auditory nerve.
This means that people with cochlear implants are not truly hearing their environment. Rather, they are hearing a digital representation. It is different from normal hearing and takes some getting used to, particularly if the person had only recently lost their hearing and thus clearly remembers normal hearing.
Are You a Candidate for Cochlear Implants?
Not everyone is a candidate for cochlear implants. A cochlear implant helps people with sensorineural hearing loss due to damaged hair cells, which send sound signals to the auditory nerve. People with conductive hearing loss will not be helped by a cochlear implant.
Candidacy for cochlear implantation varies among implant manufacturers and also differs for adults and children. In general, candidacy requirements have been relaxed somewhat since the 80s and 90s, when cochlear implants were introduced.
For adults to be considered candidates for cochlear implants, even the most relaxed requirements state that:
- There must be moderate to profound sensorineural hearing loss in both ears
- Children must have profound sensorineural hearing loss in both ears
- Candidates need to fail to meet certain thresholds for speech recognition
Other factors to consider include age and motivation. For example, the earlier a child gets a cochlear implant, the better the outcome usually is. Additionally, it must be considered if the person is prepared to work at understanding the sounds and speech conveyed by the implant, and if they have a support system in place to help them.
Cochlear Implant Surgery
Cochlear implantation is usually an outpatient surgery performed by an otolaryngologist (also known as an ear-nose-throat, or ENT, surgeon).
First, the surgeon will make a cut behind the ear and open the mastoid bone, which is part of the skull. Next, he or she will access the cochlea through the facial nerves and implant the electrode array. Then, the receiver is implanted and the incision is closed.
However, surgery is not the only part of the process, and the implant does not begin to work immediately. A few weeks later, the patient must see another specialist, such as an audiologist, to get the external parts of the implant.
Once the entire implant is assembled, the audiologist will program it. This is a process, usually taking a few visits to dial in and get the settings right. Then, the work to learn to use the new implant begins. This is known as audiologic rehabilitation, where the patient learns what the new sounds mean and how to interpret or differentiate them. The patient may even want to get therapy in order to process this potentially huge life change.
Cochlear Implant Controversy
There are some practical and even ethical considerations to make before deciding to get a cochlear implant. First is the work involved in interpreting the new signals, which is why audiologic rehabilitation is important. A person may retain some residual hearing after implantation, which the audiologist will measure during the activation appointment. Often a person may choose to wear a hearing aid on the opposite ear in order to hear from both sides.
People with cochlear implants may always have more trouble communicating than someone without hearing loss. Friends and family may not understand that it still takes work to communicate and make themselves understood by a person with cochlear implants.
Finally, there are cultural considerations. Cochlear implants are disliked in many corners of deaf culture—many members of the deaf community resent the implication cochlear implants carry that being deaf is an illness that must be cured.
At Sonora Hearing Care, we handle all aspects of cochlear implants but the surgery. We can help you determine whether you’re a candidate for cochlear implants and if cochlear implants are right for you. We will program your implants and make as many adjustments necessary until you are satisfied and help you adjust to life with your implant. Contact us today for more information.