Understanding Cochlear Implants

Medically Reviewed by Shelley A. Borgia, CCCA on March 21, 2024
13 min read

A cochlear implant (CI) is an electronic device designed to help you hear better if you're deaf, partially deaf, or have trouble understanding speech. It has two parts: a processor you wear behind your ear, and a receiver and electrode array underneath your scalp. The outside and inside parts connect through magnets. 

The device sends impulses directly to your auditory (hearing) nerve, which carries sound signals to your brain.

If you had some level of hearing before, know that a cochlear implant may not restore your hearing to the way it was, but it can help. Most people with severe to profound hearing loss can better understand speech in person or over the phone and can identify sounds like a ringing telephone, doorbell, or alarm. 

Cochlear implant parts

A cochlear implant has several components, some that you can see and others that are inside your body. They include:

  • A microphone that picks up sounds
  • A speech processor that sorts the different kinds of sounds and turns them into electronic signals
  • A transmitter outside your skull that relays the electronic signals to the internal parts
  • A receiver under your skin that picks up the sound signals and sends them to your inner ear
  • Electrodes inside your inner ear that send sound signals to your auditory nerve

You may get an implant in one ear or both, depending on your hearing ability.

Cochlear implants operate differently than hearing aids. 

Hearing aids work with your existing hearing. Whatever sound you can hear naturally, hearing aids make louder and clearer. They can be adjusted to pick up certain frequencies or filter out background noise so you can understand speech better.

Cochlear implants help you perceive sound in a different way. They bypass the structures of your ear that process sound, and work directly with the nerves that send sound signals to your brain. You don't need to have any amount of natural hearing to use them. 

Another difference is in how insurance typically handles them. Most people have to pay out of pocket for hearing aids. Medicare doesn't cover them, and neither do most private insurance plans. Under Medicaid, state-run insurance programs have to pay for hearing aids for children, and a few states cover adults too.

Cochlear implants, however, are covered by Medicare and most private insurance plans, within certain rules and limits. For example, Medicare covers implants for people who understand 60% or less of the speech they hear while using hearing aids. State-run Medicaid plans cover them for children, and most include adults also.

Cochlear implants are designed to work in people whose hearing loss is caused by damaged or missing parts of their inner ear. 

Tiny hair cells in a part of your inner ear called the cochlea are responsible for picking up the vibrations of sounds and sending them to your brain through the auditory nerve. When they’re damaged or you're born without them, sound can't reach that nerve. A cochlear implant skips the damaged hair cells and sends signals to the auditory nerve directly.

These devices have a microphone, processor, and receiver on the outside of your head. One style fits over and behind your ear, similar to a hearing aid, then attaches to a piece that secures to your scalp with a magnet. Another style has just one external piece attached to your scalp. 

The transmitter and electrodes are implanted during surgery.

When there are sounds around you, the microphone and processor pick them up and change them into electrical impulses. Then the transmitter sends these coded signals to the receiver under your skin. Next, the receiver delivers the signals to the electrodes inside your cochlea. These electrodes stimulate the auditory nerve, which carries the signals to the brain, where you recognize them as sound.

These processors can be programmed to fit your individual needs. They also can connect to assistive listening devices and other technology you use, like a smartphone. Some have rechargeable batteries, which can lower costs over time.

Getting a cochlear implant is normally an outpatient procedure, meaning you won't have to spend the night in the hospital. You'll have general anesthesia, so you'll be asleep during the surgery.

The surgeon will make a small cut behind your ear and a small hole in the bone of your skull to reach your inner ear. 

They'll place electrodes inside your cochlea that are attached to the receiver with small wires. The receiver goes under your skin behind your ear, and the incision is stitched closed. The surgery takes an hour or two.

After you've healed, which may take several weeks, you'll go back to your doctor to have the speech processor fitted and programmed. 

Then you'll start a therapy program to train your brain to process the information coming from the implant.

How long do cochlear implants last? 

The components that are implanted inside your head are designed to be permanent. However, they can be damaged or fail and need to be replaced with another surgery. 

The parts on the outside can be expected to last around 5-7 years, about as long as a hearing aid.

Cochlear implants are approved by the FDA for adults and for children as young as 9 months, under certain circumstances. But they aren't appropriate for everyone who has hearing loss. For example, if you were born without cochlear nerves, or if those nerves were destroyed, a cochlear implant won't work.  

You may benefit from the device if you have:

  • Moderate to profound hearing loss in one or both ears
  • Hearing loss after you’ve already learned speech and language
  • Limited help from hearing aids
  • No medical problems that would make surgery risky
  • A good understanding of what the device will -- and won’t -- do for you
  • A strong commitment to an auditory therapy program  

Also, cochlear implants work better for people who have lost their hearing recently, as well as those who’ve already used a hearing aid successfully.

It's more difficult to learn language if you can't hear it, so if your child is born with or develops hearing loss, you'll need to take steps right from the start to be sure they have full access to language and communication skills. A cochlear implant can be a part of that.  

The FDA has approved certain kinds of devices for babies as young as 9 months. The younger the child, the more significant the hearing loss needs to be to qualify. For babies 9-24 months, it must be profound, meaning they can't hear sounds below 90 decibels. Children 2-17 years old qualify with severe-to-profound hearing loss, which means not hearing sound below 70 decibels.

Depending on your child's hearing situation, your doctor may recommend implants in both ears. 

In general, for children born with significant hearing loss, the younger they are when they get the implant, the more benefit they'll get from it. Research has shown that children who get a cochlear implant and have intensive therapy before 18 months are better able to hear and speak than children who get implants when they're older and can learn language skills as quickly as as children born with hearing. 

Similar to adults, the devices can benefit children who:

  • Get limited help from hearing aids
  • Are healthy, with no medical problems that would make surgery risky
  • Are ready to learn how to communicate with a cochlear implant
  • Have support from their parents, teachers, and school programs to help them gain hearing skills
  • Join in intensive speech therapy and programs to teach speaking skills

For older children who lose their hearing after they’ve learned to talk, the benefit of an implant is greater the sooner they get it. 

Whether to get an implant for your child is a personal, family decision. Some feel that deafness isn't something that needs to be "fixed" and kids shouldn't be given implants until they're old enough to make their own choice. 

Experts recommend using a visual language like American Sign Language with your child as early as possible, whether you also opt for implants or not.

If you or your child has hearing loss, a team of experts can help you decide if the device will be useful. Typically, these experts include an ear doctor called an otologist, an audiologist, a psychologist, and a speech-language pathologist. The team works together to determine if you're a good fit for a cochlear implant, do the surgery, and offer follow-up care.

Cochlear implant tests

You may have tests, such as:

  • An exam of your external, middle, and inner ear to check for infections or other issues
  • Hearing tests such as an audiogram, a graph that charts how you respond to specific sounds
  • A hearing aid evaluation
  • Imaging tests like computerized tomography (CT) or magnetic resonance imaging (MRI) scans to check the inner ear and hearing nerve. These tests will show whether the shape of your cochlea will fit an implant.
  • A physical exam
  • A psychological exam to see if you can handle the changes that come with the implant

When you're thinking about getting a cochlear implant, counseling will help you know what you can expect from the device and make sure you understand what it takes to learn how to use the implant. 

Not everyone gets the same results from a cochlear implant. It can take a lot for your brain to learn to process the signals from the device. You may need extensive therapy over many months to get the most out of it. But potential benefits include: 

  • You may be able to hear speech nearly as well as you used to.
  • You may be able to understand speech when you can't see someone's mouth, or in a noisy place. 
  • You may be able to recognize different sounds, including those that can warn you of danger, like an alarm, car engine, or barking dog. 
  • You may be able to sense where different sounds are coming from.
  • If you have buzzing or ringing in the ear that gets the implant (tinnitus), it may improve.
  • The implant may allow you to hear and adjust your own voice.

Your experience with a cochlear implant will depend on many things, including how and when you lost your hearing and how consistently you wear the device.  

Cochlear implant surgery is very safe, but any operation comes with risks. Problems can include bleeding, infection, and side effects from the medicine that sends you to sleep during the procedure.

Other possible complications include:

  • A nerve injury that changes your sense of taste
  • Nerve damage that causes weakness or paralysis in your face
  • Dizziness or balance problems
  • Loss of remaining hearing in the treated ear
  • Ringing in your ears, called tinnitus
  • Leaking of the fluid around the brain
  • Meningitis, an infection of the membranes around the brain. It’s a rare but serious complication. Children and people with abnormally formed inner ears seem to be at higher risk. The FDA and CDC recommend vaccines for anyone who gets a cochlear implant to lower their risk for the disease.

Keep some other things in mind, too:

If you have some hearing left, sound may seem "mechanical" or "synthetic," although most people no longer notice this after several months.

Rarely, the implant may stop working, and you’d need surgery to fix the problem.

Cochlear implants are very expensive. One analysis found average prices of the three brands of devices sold in the U.S. to be between $25,000 and $40,000. The surgery and follow-up add tens of thousands of dollars to the total cost of getting an implant. 

Then there's maintenance. Cochlear implants take batteries, and you may need fresh ones every day. Also, the processors have to be replaced or upgraded every five years or so. And if parts get damaged, you may have to pay for the repair.  

If you have private insurance or government-funded care like Medicare or Medicaid, some or all of the cost may be covered. But you'll need to check with your plan.

Some parts of the device will come with a manufacturer's warranty that you may be able to pay to extend. Personal property or homeowner's insurance may cover loss or damage, depending on the circumstances. 

Cochlear implants aren't for everyone, and they don't fully restore your hearing. There are other ways to manage hearing loss and to communicate, which you can use instead of or combined with a cochlear implant.

Visual language. You or your child can learn to converse using nonverbal methods including signs, gestures, facial expressions, finger spelling, and speech reading. American Sign Language is the most common complete visual language used in the U.S. 

Assistive listening technology. This can be a handheld personal device or a larger system used in places like auditoriums. It makes certain sounds louder and lowers background noise to help hearing aids or a cochlear implant work better. 

Augmentative and alternative communication methods. These can be as simple as texting or pointing to pictures or symbols on a screen. More sophisticated technology includes devices that can turn text into speech or vice versa, and translate text or speech into American Sign Language. Captioning systems make it easier to use the television and telephone.

Alerting devices. You can get gadgets that flash a light or vibrate to let you know things like the phone is ringing or the baby is crying.

Hearing aids. Designed to make sounds louder and clearer, these come in a variety of styles that you can get either by prescription or over-the-counter. They're most commonly worn behind your ears, in your outer ear, or inside your ear canal. Another kind of hearing aid can be implanted in your middle ear or attached to the bone of your skull to send sound vibrations to your inner ear. 

Brain stem implant. This can allow you to sense sound if your auditory nerves don't work or if a cochlear implant won't fit in your ear.

You'll get the most from a cochlear implant if you wear it all the time and work with a hearing therapist. You'll also need to check in with your doctor every so often for the rest of your life to test your hearing and adjust the device.

Other things to keep in mind:

Don't get the implant wet. Some parts of the device can get damaged if they get wet. You need to take off the speech processor before you bathe, shower, or swim. You also can cover that part with a waterproof case or choose a waterproof cochlear implant processor.

Scuba diving in deep water (beyond about 60 feet) isn't recommended because the water pressure can damage the internal parts. 

Be careful with contact sports. The internal parts of a cochlear implant can get knocked out of place if you take a hard hit or fall and hit your head. Wear a helmet when you play sports like football, and also if you're bicycling, skating, or skiing. You may need to find one specially fitted to make room for the processor. Some sports, like boxing and martial arts, are very difficult to do safely with an implant. 

For other activities where you aren't likely to take a hit, a sports headband to help hold the external parts in place is enough.

Plan ahead for certain medical procedures. The powerful magnets used in an MRI machine can damage or move the internal parts of the implant, even if you're just standing near it. If you need an MRI, you'll have to take certain precautions depending on what kind of device you have. You may first need a procedure to briefly take out the implanted magnet, but that's less common with newer technology.

Some medical treatments may not be possible for you, including ionic radiation therapy, electrical surgery, electroconvulsive therapy, or neurostimulation. 

Beware of static and electrical or magnetic interference.  The little zap you get from static electricity can damage the processor. You should remove it before touching things like synthetic fabric or a TV screen. It could set off a store's theft detection system or a metal detector. You can carry a special cochlear implant identification card or a letter from your doctor to explain the situation.

You may get interference from people's cell phones or other radio transmissions. It may be necessary to turn it off during takeoff and landing when you fly. Being around devices with a magnetic field, like an airport screening machine, can cause strange sounds. It may be best to take the processor off and hand it to the screener. 

A cochlear implant is an electronic device that allows a deaf person to hear better. It includes parts that are implanted inside your ear and under your skin, and parts you wear on the outside of your head. It can help you or your child better understand speech and identify different sounds, but not everyone gets the same results. 

Can a deaf person hear after a cochlear implant?

Yes, although not everyone gets the same results. Some people can understand speech nearly as well as they did before they lost their hearing. 

Can you talk on the phone with cochlear implant?

Yes, but it takes practice. You may be able to connect your phone to your implant with Bluetooth or an assistive listening devices, or hold it near the microphone. Tell the person who's talking to speak slowly and clearly in a spot without a lot of background noise.

What is the life expectancy of a cochlear implant?

The parts implanted inside your head are designed to be permanent. The outside parts will probably need to be replaced or upgraded every 5-7 years.