What Is a Cochlear Implant?
A cochlear implant is a device surgically placed by an ear, nose, and throat (ENT) physician and provides a person who has moderate-to-profound sensorineural hearing loss with sound perception. Cochlear implants allow for improved sound awareness and speech understanding in both quiet and noisy environments.
What Is the Difference Between Cochlear Implants and Hearing Aids?
While a traditional hearing aid sits on the outside of the ear and sends sound through the entire outer-, middle-, and inner-ear system, the cochlear implant is surgically placed within the inner ear, inside the damaged cochlea. The implant then sends electrical signals directly to the hearing nerve. Sound is sent to the implant from a device that sits on the outside of the head, which stays in place with a magnet.
How Does a Cochlear Implant Work?
A cochlear implant is a two-part device. The external portion, called the processor, picks up acoustic sound. The sound is then processed and sent via electric signal to the internal portion. After receiving the signal, the internal portion sends it to the electrodes placed in the cochlea. The electrodes send small pulses to the hearing nerve which then sends the signal to the brain.
What Do Cochlear Implants Look Like?
Often cochlear implants look like large hearing aids with a cable coming off the back. The cable then sits slightly above the rest of the device. There are some off-ear processors available, which sit slightly above the ear and are about the size and shape of a half-dollar. All external processors come in a variety of colors.
Who Can Get a Cochlear Implant?
When hearing loss is severe, there may be significant damage to the inner ear or the cochlea. When there is substantial damage to the cochlea, a hearing aid may not be able to provide enough help with improving access to sound. If hearing aids are no longer beneficial, a cochlear implant may be considered as the next option. Candidacy in the United States varies based on age, hearing loss, and cause of hearing loss. Below are the FDA requirements for candidacy. These may vary based on your specific case (cause of hearing loss, anatomy, etc.) and your implant team.
A child is considered a cochlear implant candidate if they have a severe to profound sensorineural hearing loss and are not benefiting from hearing aids. Benefit is evaluated by a parent questionnaire. The questions will determine if your child can respond to sounds with their hearing aids on, and if they’re old enough, a physician or audiologist will evaluate how well they can repeat back words.
Children must be at least nine months old to receive cochlear implants. Typically, a child will be evaluated by a pediatric audiologist, an ENT, an auditory-verbal therapist (a speech pathologist with additional training to work with people with hearing loss), and possibly a psychologist. After all testing is completed, you will meet with your hearing health-care team to discuss if your child is a candidate for a cochlear implant and what to expect for your child’s specific case.
An adult is considered a cochlear implant candidate if they have moderate to profound sensorineural hearing loss and worse than 60 percent speech understanding when using appropriately fit hearing aids. You can have good hearing in the low pitches and still be considered an implant candidate. You will be evaluated by an audiologist and an ENT to determine if you meet candidacy criteria. They may also recommend working with an auditory-verbal therapist and a psychologist based on your individual needs.
What Is Cochlear Implant Surgery?
Cochlear implant surgery is typically an outpatient procedure performed by an ENT.
Prior to surgery, your team will run pre-operative labs and ensure you are up to date on any necessary vaccines. When you arrive at the surgery center, you will be prepared for your procedure and meet the team assisting your surgeon.
During your procedure, you will be asleep with anesthesia. The surgeon will create an incision behind your ear and proceed to the middle ear space. Once in the middle ear, they will visualize the cochlea and create a small opening. The implant is placed on the skull and the electrode is slowly guided into the cochlea. Once this is complete, the surgeon or an audiologist will check the placement of the device with an x-ray and run some preliminary tests on the implant to ensure it is functioning. These tests are called impedances and/or telemetry. Surgery takes approximately one hour.
After surgery, most patients go home the same day. After the surgery, the ear is given some time to heal. One to four weeks after surgery, the cochlear implant gets “activated,” which is when sound is turned on and the device is programmed with an audiologist.
On this day, sounds are not usually clear—some people say they hear beeps and squeaks, while others say they hear robotic or cartoon voices. Over time, listening performance improves (Wilson and Dorman, 2008), but this process requires practice and effort. Within the first year of having the implant, one should return regularly to update the device settings, to ensure you are receiving the maximum benefit from the device.
It is important to remember that each person’s performance and experience can be different with a cochlear implant, depending on the cause of hearing loss (Blamey et al, 2013) and duration of hearing loss (Rubenstein et al, 1999). The audiologist will guide you through the entire process and can help establish realistic expectations and provide strategies for success for your situation.
Risks of cochlear implantation include:
- General anesthesia risks
- Injury to the facial nerve
- Cerebrospinal fluid leak
- Perilymph fluid leak
- Infection of the skin
- Blood or fluid collection at the surgical site
- Changes in taste
- Numbness around the ear
- Other unforeseen complications (Centers for Devices, 2021)
How Much Does a Cochlear Implant Cost?
Most insurance carriers, including Medicare and Medicaid, cover at least some costs associated with cochlear implants. However, each plan varies, so it is important to investigate the details of your policy for specific information.
When Will an Audiologist Recommend a Cochlear Implant?
As each patient is different, an implant may be recommended at various points in your hearing journey. If you feel you are struggling to understand people around you with your hearing aids, consider asking your audiologist about a cochlear implant. They may need to refer you to another audiologist for an evaluation. As a general rule, when your pure-tone average is 60 dB or louder, and your word recognition is 60 percent or worse, you may qualify for a cochlear implant and should be evaluated (Zwolan et al, 2020).
How Long Do Cochlear Implants Last?
Internal cochlear implants are developed to last a lifetime.
External cochlear implants have a similar lifespan to a hearing aid—five to seven years.
Do You Need a Cochlear Implant? Ask an Audiologist.
If you use hearing aids and have significant difficulty communicating, ask your audiologist about cochlear implants.
Blarney P, Arndt P, Bergeron F, et al (1996). Factors affecting auditory performance of postlinguistically deaf adults using cochlear implants. Audiol Neuro 1(5):293–306.
Rubinstein JT, Parkinson WS, Tyler RS, Gantz BJ. (1999) Residual speech recognition and cochlear implant performance: effects of implantation criteria. Amer J Otolo 20(4):445–452.
Center for Devices and Radiological Health. (2021) Benefits and risks of cochlear implants. U.S. Food and Drug Administration. www.fda.gov/medical-devices/cochlear-implants/benefits-and-risks-cochlear-implants (accessed June 14, 2022).
Wilson BS, Dorman MF. (2008) Interfacing sensors with the nervous system: Lessons from the development and success of the cochlear implant. IEEE Sensors J 8(1):131–147.
Zwolan TA, Schvartz-Leyzac KC, Pleasant T. (2020) Development of a 60/60 guideline for referring adults for a traditional cochlear implant candidacy evaluation. Otol Neurotol 41(7), 895-900.