Cochlear Implants vs. Hearing Aids: What’s the Difference?

Key Takeaways: Cochlear Implants vs. Hearing Aids

• Cochlear implants help deaf or hard-of-hearing people interpret sound, but they do not restore typical hearing.
• Hearing aids make sound louder, while cochlear implants directly stimulate the auditory nerve to allow the brain to process sound.
• All cochlear implants feature external and internal components: a microphone, speech processor, transmitter and receiver-stimulator, and electrode array.
• Surgery to implant the device is generally safe and usually takes about two hours.
• Rehabilitation is important after receiving implants to help the brain get used to receiving and interpreting signals from them.

While both hearing aids and cochlear implants can treat hearing loss, cochlear implants stimulate the auditory nerve, which is where the brain receives the signals it interprets into sound. As of 2019, doctors around the globe had implanted almost 737,000 cochlear implants. People as young as nine months old who either can’t hear at all or have profound hearing loss may benefit from cochlear implants.

Implants may also be appropriate for people with moderate to severe hearing loss, even after using hearing aids. But while you can get hearing aids through a prescription or over-the-counter, depending on your level of hearing loss, cochlear implants require surgery.

What are cochlear implants?

Cochlear implants are small electronic devices with an external sound processor and an internally implanted electrode placed inside the inner ear. The U.S. Food and Drug Administration (FDA) approved cochlear implants for adults in the 1980s. The FDA later approved cochlear implants for use in children in 1990 for ages two and up and later lowered the age limit to 12 months in 2000. Today, children as young as nine months old are able to receive cochlear implants.

While several types of cochlear implants exist, they all feature the following components:

• Microphone: This detects sound in the environment.
• Speech processor: This helps to arrange whatever sound the microphone detects into electrical signals. 
• Transmitter and receiver-stimulator: These components receive electrical signals from the speech processor and change them into electrical impulses.
• Electrode array: Located inside the inner ear, the electrode array gathers any impulse sent by the stimulator. Then, the array sends those impulses to the auditory nerve.

When the auditory nerve receives an impulse, it sends that impulse to the brain, which then interprets the impulse as sound.

How do cochlear implants work?

Unlike hearing aids, which make sounds louder, cochlear implants directly stimulate the auditory nerve. Doctors may recommend implants for one or both ears. 

Understanding how the brain normally processes and interprets sound helps explain how cochlear implants work. Sound waves from the environment normally cause vibrations in the eardrum and in three small bones located in the middle ear. The inner ear then receives these vibrations and turns them into electrical signals. Finally, those signals travel along the auditory nerve to the brain, where they’re interpreted as different sounds.

People who receive cochlear implants have damage to one or several parts of the ear. This damage prevents the formation of electrical signals that the brain ultimately interprets as sound. Deafness or profound hearing loss occurs when the brain never receives any signals to process.

Cochlear implants bypass any damage to the ear, allowing people to receive and interpret sound, but they do not restore typical hearing. People with cochlear implants who previously had normal hearing describe the sound as “robotic” or like an “off-tuned radio.”

What is the difference between a cochlear implant and a hearing aid?

Many people with mild to severe hearing loss benefit from hearing aids, which amplify sounds from the environment. In other words, hearing aids make sounds louder, so they’re easier for the ear to pick up. In contrast, cochlear implants directly stimulate the auditory nerve to send signals to the brain, which are recognized as sounds. 

Who would benefit from a cochlear implant?

Cochlear implants aren’t for everyone—people who are deaf or have severe hearing loss in one or both ears are ideal candidates for implant surgery. If hearing aids can treat your hearing loss, you shouldn’t receive cochlear implants.

Both children and adults can qualify for cochlear implant surgery. This is especially important for young children who can’t hear since kids develop speech and language skills in their early years. According to some research, deaf or severely hard-of-hearing children less than 18 months of age who receive cochlear implants can develop their language skills similarly to children with typical hearing. But according to Rachel Magann Faivre, AuD, owner of Oklahoma City-based Ash Audiology, this is in addition to “lots of aural rehab, typically provided by a speech-language pathologist who specializes in kids with hearing loss, as well as help from the pediatric audiologist. These therapy sessions typically last for a few years.” Keep in mind a person doesn’t have to be born deaf to receive cochlear implants. Any person who loses their ability to hear later in life can also benefit from implant surgery.

“Every person has to wear or try hearing aids before receiving a cochlear implant,” said Magann Faivre. “This is because the testing required to prove medical necessity for a cochlear implant includes hearing tests while wearing hearing aids. If the patient scores poorly enough, then the patient can qualify for a cochlear implant. Two people with the same severe hearing loss can have drastically different results hearing with hearing aids.”

Receiving cochlear implants

Surgeons perform an operation to place cochlear implants in selected candidates’ ears. Doctors use general anesthesia to keep patients in a deep, sleep-like state. Because of this, your surgeon may tell you not to eat or drink prior to surgery. Additionally, you may need to stop taking certain supplements or medications before your surgery.

You should also understand the risks of the procedure. This type of surgery is generally safe. But like all surgeries, cochlear implant placement comes with risks, such as:

• Balance problems
• Bleeding
• Dizziness
• Facial paralysis
• Infection
• New or worsening ringing in the ear
• Numbness around the ear
• Problems with taste 
• Spinal fluid leaks
• Swelling

Although rarely, the implant may fail, resulting in another surgery to repair or replace the defective device. Some people experience residual hearing loss. This means any remaining hearing ability in the implanted ear may go away. 

Also possible but rare, a condition called meningitis may occur. Meningitis is the inflammation of the tissues surrounding the brain and spinal cord. Your doctor may recommend vaccinating against meningitis before your procedure to help offset this risk.

Most people don’t have to remain in the hospital overnight after the procedure. Cochlear implant placement surgeries are usually outpatient procedures. Unless something happens during or soon after the surgery, you’ll likely go home the same day.

Before the procedure

Before you can have the surgery, you’ll have a series of tests and evaluations to determine whether the implants are your best option.

Your doctor gathers information by taking your history and performing a physical exam. You’ll also complete hearing and speech tests. Balance tests may also help doctors determine the extent of damage to your ears. 

Additionally, your doctor may suggest a computerized tomography (CT) scan or magnetic resonance imaging (MRI). These specialized tests produce detailed pictures of your inner ear, which helps your doctor plan your surgery.

Beyond testing, you’ll work with a member of the health care team known as an audiologist. Audiologists help determine the extent of your hearing loss and will help you select the cochlear implant that’s right for you. Here are the two general types of implants:

• An inner ear implant with an external sound processor attaches to the side of the head.
• An inner ear implant with an external sound processor sits behind the ear.

During the procedure

For most people, cochlear implant surgery takes about two hours, either in a hospital or an outpatient surgery clinic. You’ll receive certain medications, known as general anesthesia, to help you stay asleep throughout the procedure. A care team member may shave off the hair behind your ear. 

To begin, a surgeon makes a cut, or incision, behind the affected ear. Using a small microscope and bone drill, the surgeon creates a small hole in the bone behind the ear. This allows the surgeon to implant the device’s electrode array into the inner ear. 

After the array is implanted, the surgeon places the receiver into a small pocket behind the ear between the bone and muscle tissue. This keeps the receiver in the correct position and allows it to send electrical impulses to the array. After all the components of the implant are in place, the surgeon closes the cut behind the ear with sutures or stitches. 

Some surgeons cover the surgery site with a large wound dressing. If this happens, your doctor will tell you when to remove the dressing. You may also get prescriptions for pain medications and antibiotics to help prevent infection. 

After the procedure

Following your surgery, you’ll spend a few hours in the hospital or clinic recovering while your doctor monitors you for any problems. Then, you can go home. In one to four weeks, your audiologist will place the external portion of the cochlear implant in the correct location. This gives the cut enough time to heal completely.

Rehabilitation is an extremely important part of cochlear implant surgery. During rehab, your brain learns to interpret sounds picked up by the cochlear implant. Keep in mind the implant will not restore typical hearing—speech and other sounds will likely sound different from what you remember, if you were able to hear in the past.

Rehab appointments generally take place throughout the course of four to six weeks. During these appointments, you’ll work with an audiologist to learn how to use the external portion of the implant. Your appointments with your audiologist will be ongoing over the course of months to fine-tune your implant as your brain gets used to new sounds. You may also work with speech therapists or ear, nose, and throat (ENT) doctors to get the most benefit from the implant as possible.

Your health care team will tell you everything else you need to know about caring for your implant, what activities you should avoid, and when you should contact your doctor. If you ever have questions or concerns, it’s best to get in touch with your health care team.

Bottom line

Cochlear implants help deaf or hard-of-hearing children and adults recognize and understand sound. They are different from hearing aids, which simply make sounds louder. You’ll need to have surgery to receive a cochlear implant, and not everyone is a good candidate for surgery.

Be sure to talk with your doctor about the benefits and risks of cochlear implant surgery if you think it could be right for you. This type of surgery is generally safe and could help you hear speech, music, television programs, and other everyday environmental sounds.

Have questions about this review? Email us at reviewsteam@ncoa.org.

Sources

1. National Institute on Deafness and Other Communication Disorders. Cochlear Implants. Updated March 24, 2021. Found on the internet at https://www.nidcd.nih.gov/health/cochlear-implants
2. Mayo Clinic. How You Hear. Aug. 15, 2023. Found on the internet at https://www.mayoclinic.org/diseases-conditions/hearing-loss/in-depth/ear-infections/art-20546801
3. National Institute on Deafness and Other Communication Disorders. How Do We Hear? Updated March 16, 2022. Found on the internet at https://www.nidcd.nih.gov/health/how-do-we-hear
4. Cejas I., et al. Cochlear Implantation and Educational and Quality-of-Life Outcomes in Adolescence. JAMA Otolaryngology–Head & Neck Surgery. June 29, 2023. Found on the internet at https://jamanetwork.com/journals/jamaotolaryngology/article-abstract/2806314
5. Johns Hopkins Medicine. Cochlear Implant Surgery and Rehabilitation. Found on the internet at https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/cochlear-implant-surgery
6. National Library of Medicine. Cochlear Implant. Updated June 4, 2023. Found on the internet at https://medlineplus.gov/ency/article/007203.htm