http://www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/ImplantsandProsthetics/CochlearImplants/default.htm

Cochlear Implants

Welcome to the Food and Drug Administration (FDA) website on cochlear implants. Cochlear implants are electronic hearing devices. Doctors implant cochlear implants into people with severe to profound hearing loss to produce useful hearing sensations.

The purpose of this website is to describe cochlear implants, link to FDA-approved implants, tell the benefits and risks of cochlear implants, and provide news about cochlear implant recalls and safety issues. You can find information here too on what educators of implant users need to know, what happens before, during and after surgery, and where to report problems.

The FDA regulates manufacturers of cochlear implants. For manufacturers to sell cochlear implants in the United States, they must first show the FDA that their implants are safe and effective. As a matter of policy, FDA does not rate or recommend brands of cochlear implants or medical facilities that implant them.

What are the Benefits of Cochlear Implants?

For people with implants:

• Hearing ranges from near normal ability to understand speech to no hearing benefit at all.
• Adults often benefit immediately and continue to improve for about 3 months after the initial tuning sessions. Then, although performance continues to improve, improvements are slower. Cochlear implant users' performances may continue to improve for several years.
• Children may improve at a slower pace. A lot of training is needed after implantation to help the child use the new 'hearing' he or she now experiences.
• Most perceive loud, medium and soft sounds. People report that they can perceive different types of sounds, such as footsteps, slamming of doors, sounds of engines, ringing of the telephone, barking of dogs, whistling of the tea kettle, rustling of leaves, the sound of a light switch being switched on and off, and so on.
• Many understand speech without lip-reading. However, even if this is not possible, using the implant helps lip-reading.
• Many can make telephone calls and understand familiar voices over the telephone. Some good performers can make normal telephone calls and even understand an unfamiliar speaker. However, not all people who have implants are able to use the phone.
• Many can watch TV more easily, especially when they can also see the speaker's face. However, listening to the radio is often more difficult as there are no visual cues available.
• Some can enjoy music. Some enjoy the sound of certain instruments (piano or guitar, for example) and certain voices. Others do not hear well enough to enjoy music.

What are the Risks of Cochlear Implants?

General Anesthesia Risks

• General anesthesia is drug-induced sleep. The drugs, such as anesthetic gases and injected drugs, may affect people differently. For most people, the risk of general anesthesia is very low. However, for some people with certain medical conditions, it is more risky.

Risks from the Surgical Implant Procedure

• Injury to the facial nerve --this nerve goes through the middle ear to give movement to the muscles of the face. It lies close to where the surgeon needs to place the implant, and thus it can be injured during the surgery. An injury can cause a temporary or permanent weakening or full paralysis on the same side of the face as the implant.
• Meningitis --this is an infection of the lining of the surface of the brain. People who have abnormally formed inner ear structures appear to be at greater risk of this rare, but serious complication. For more information on the risk of meningitis in cochlear recipients, see the nearby Useful Links.
• Cerebrospinal fluid leakage --the brain is surrounded by fluid that may leak from a hole created in the inner ear or elsewhere from a hole in the covering of the brain as a result of the surgical procedure.
• Perilymph fluid leak --the inner ear or cochlea contains fluid. This fluid can leak through the hole that was created to place the implant.
• Infection of the skin wound.
• Blood or fluid collection at the site of surgery.
• Attacks of dizziness or vertigo.
• Tinnitus, which is a ringing or buzzing sound in the ear.
• Taste disturbances --the nerve that gives taste sensation to the tongue also goes through the middle ear and might be injured during the surgery.
• Numbness around the ear.
• Reparative granuloma --this is the result of localized inflammation that can occur if the body rejects the implant.
• There may be other unforeseen complications that could occur with long term implantation that we cannot now predict.

Other Risks Associated with the Use of Cochlear Implants

People with a cochlear implant:

• May hear sounds differently. Sound impressions from an implant differ from normal hearing, according to people who could hear before they became deaf. At first, users describe the sound as "mechanical", "technical", or "synthetic". This perception changes over time, and most users do not notice this artificial sound quality after a few weeks of cochlear implant use.
• May lose residual hearing. The implant may destroy any remaining hearing in the implanted ear.
• May have unknown and uncertain effects. The cochlear implant stimulates the nerves directly with electrical currents. Although this stimulation appears to be safe, the long term effect of these electrical currents on the nerves is unknown.
• May not hear as well as others who have had successful outcomes with their implants.
• May not be able to understand language well. There is no test a person can take before surgery that will predict how well he or she will understand language after surgery.
• May have to have it removed temporarily or permanently if an infection develops after the implant surgery. However, this is a rare complication.
• May have their implant fail. In this situation, a person with an implant would need to have additional surgery to resolve this problem and would be exposed to the risks of surgery again.
• May not be able to upgrade their implant when new external components become available. Implanted parts are usually compatible with improved external parts. That way, as advances in technology develop, one can upgrade his or her implant by changing only its external parts. In some cases, though, this won't work and the implant will need changing.
• May not be able to have some medical examinations and treatments. These treatments include:
• MRI imaging. MRI is becoming a more routine diagnostic method for early detection of medical problems. Even being close to an MRI imaging unit will be dangerous because it may dislodge the implant or demagnetize its internal magnet. FDA has approved some implants, however, for some types of MRI studies done under controlled conditions.
• neurostimulation.
• electrical surgery.
• electroconvulsive therapy.
• ionic radiation therapy.
• Will depend on batteries for hearing. For some devices new or recharged batteries are needed every day.
• May damage their implant. Contact sports, automobile accidents, slips and falls, or other impacts near the ear can damage the implant. This may mean needing a new implant and more surgery. It is unknown whether a new implant would work as well as the old one.
• May find them expensive. Replacing damaged or lost parts may be expensive.
• Will have to use it for the rest of life. During a person's lifetime, the manufacturer of the cochlear implant could go out of business. Whether a person will be able to get replacement parts or other customer service in the future is uncertain.
• May have lifestyle changes because their implant will interact with the electronic environment. An implant may
• set off theft detection systems
• set off metal detectors or other security systems
• be affected by cellular phone users or other radio transmitters
• have to be turned off during take offs and landings in aircraft
• interact in unpredictable ways with other computer systems
• Will have to be careful of static electricity. Static electricity may temporarily or permanently damage a cochlear implant. It may be good practice to remove the processor and headset before contact with static generating materials such as children's plastic play equipment, TV screens, computer monitors, or synthetic fabric. For more details regarding how to deal with static electricity, contact the manufacturer or implant center.
• Have less ability to hear both soft sounds and loud sounds without changing the sensitivity of the implant. The sensitivity of normal hearing is adjusted continuously by the brain, but the design of cochlear implants requires that a person manually change sensitivity setting of the device as the sound environment changes.
• May develop irritation where the external part rubs on the skin and have to remove it for a while.
• Can't let the external parts get wet. Damage from water may be expensive to repair and the person may be without hearing until the implant is repaired. Thus, the person will need to remove the external parts of the device when bathing, showering, swimming, or participating in water sports.
• May hear strange sounds caused by its interaction with magnetic fields, like those near airport passenger screening machines.-

Before, During, & After Implant Surgery

What happens before surgery?

Primary care doctors usually refer patients to ear, nose and throat doctors (ENT doctors or otolaryngologists) to test them to see if they are candidates for cochlear implants.

Tests often done are:

• examination of external, middle, and inner ear for signs of infection or abnormality
• various tests of hearing, such as an audiogram
• a trial of hearing aid use to assess its potential benefit
• exams to evaluate middle and inner ear structures
• CT (computerized tomography) scan. This type of x-ray helps the doctor see if the cochlea has a normal shape. This scan is especially important if the patient has a history of meningitis because it helps see if there is new bone growth in the cochlea that could interfere with the insertion of the implant. This scan also may indicate which ear should be implanted.
• MRI (magnetic resonance imaging) scan
• psychological examination to see if the patient can cope with the implant
• physical exam to prepare for general anesthesia

What happens during surgery?

The doctor or other hospital staff may:

• insert some intravenous (i.v.) lines
• shave or clean the scalp around the site of the implant
• attach cables, monitors and patches to the patient's skin to monitor vital signs
• put a mask on the patient's face to provide oxygen and anesthetic gas
• administer drugs through the i.v. and the face mask to cause sleep and general anesthesia
• awaken the patient in the operating room and take him or her to a recovery room until all the anesthesia is gone

What happens after surgery?

Immediately after waking, a patient may feel:

• pressure or discomfort over his (or her) implanted ear
• dizziness
• sick to the stomach (have nausea)
• disoriented or confused for a while
• a sore throat for a while from the breathing tube used during general anesthesia

Then, a patient can expect to:

• keep the bandages on for a while
• have the bandages be stained with some blood or fluid
• go home in about a day after surgery
• have stitches for a while
• get instructions about caring for the stitches, washing the head, showering, and general care and diet
• have an appointment in about a week to the stitches removed and have the implant site examined
• have the implant "turned on" (activated) about 3-6 weeks later

Can a patient hear immediately after the operation?

No. Without the external transmitter part of the implant a patient cannot hear. The clinic will give the patient the external components about a month after the implant surgery in the first programming session.

Why is it necessary to wait 3 to 6 weeks after the operation before receiving the external transmitter and sound processor?

The waiting period provides time for the operative incision to heal completely. This usually takes 3 to 6 weeks. After the swelling is gone, your clinician can do the first fitting and programming.

What happens during the initial programming session?

An audiologist adjusts the sound processor to fit the implanted patient, tests the patient to ensure that the adjustments are correct, determines what sounds the patient hears, and gives information on the proper care and use of the device.

Is it beneficial if a family member participates in the training program?

Yes! A family member should be included in the training program whenever possible to provide assistance. The family member should know how to manage the operations of the sound processor.

Do patients have more than one implant?

Usually, patients have only one ear implanted, though a few patients have implants in both ears.

How can I help my child receive the most benefit from their cochlear implant?

• try to make hearing and listening as interesting and fun as possible
• encourage your child to make noises
• talk about things you do as you do them
• Show your child that he or she can consciously use and evaluate the sounds he or she receives from his or her cochlear implant
• realize that the more committed you, your child's teachers, and your health professionals are to helping your child, the more successful he or she will be

What can I expect a cochlear implant to achieve in my child?

As a group, children are more adaptable and better able to learn than adults. Thus, they can benefit more from a cochlear implant. Significant hearing loss slows a child's ability to learn to talk and affects overall language development. The vocal quality and intelligibility of speech from children using cochlear implants seems to be better than from children who only have acoustic hearing aids.

How important is the active cooperation of the patient?

Extremely important. The patient's willingness to experience new acoustic sounds and cooperate in an auditory training program are critical to the degree of success with the implant. The duration and complexity of the training varies from patient to patient.

What Educators Need to Know

• Cochlear implants do not make hearing normal.
• Benefit of an implant depends, in part, on the
• type of communication training (total communication, auditory-oral communication, cued speech, etc.) a student used before the implant
• type of communication the student uses after the implant
• To get maximum benefit from a cochlear implant, a student will need individual training, such as
• speech training
• lip reading training
• auditory training
• To progress with their classmates, students with cochlear implants may still need
• special accommodation in the classroom
• preferential seating
• a note taker
• a quiet environment, away from air handlers and other noisy equipment
• a sign-language interpreter or cued speech interpreter
• Students need time to adjust and accommodate to their cochlear implants. The amount of time they need varies. During the accommodation period, students need language input from all sources they used before their implants.
• Educators should treat their students with cochlear implants as individuals, each having particular communication needs. Students don't get equal benefits from cochlear implants.
• Students with cochlear implants may find it harder to
• digest new and difficult subject matter
• interact in unfamiliar and complex social situations
• Educators should be aware that frequent changes to educational programs involving students with cochlear implants (program hopping) may impede learning.
• Educators can help their students in other ways to achieve full benefits from cochlear implants,
• intervening early when there appears to be a problem
• promoting family counseling
• promoting specialized speech and language therapies
• explaining to families that speech and language are not the same thing, and that education is based on language development
• getting more information and support from local and national organizations of teachers of those with impaired hearing
• To assure that students with cochlear implants don't fall behind their classmates, educators should frequently evaluate them and their educational settings.
• Particularly for their younger students, educators need to assure that external cochlear implant components are securely attached or removed during active school events. The components are expensive and are easily lost or damaged.
• Students will often need extra batteries, either new or recharged, for their implants to work.
• Students with cochlear implants are usually not able to interpret complex auditory signals, such as those in music.