Q. How does a cochlear implant work?
A. A cochlear implant works as follows (see diagram):
- Similar to a hearing aid, acoustic sound is captured by the microphones on the speech processor.
- The speech processor analyzes the signal and converts it into digital codes.
- This digital signal is then sent via the cable to the coil of the processor, which stays connected to the patient’s head via a magnet. The signal is transferred through the headpiece by frequency modulation (FM) across the skin to the internal implant under the skin.
- The implant turns the received digital information into electrical information that travels down the electrode array to the auditory nerve.
- The auditory nerve sends impulses to the brain, where they are interpreted as sound.
Q. Is cochlear implant technology new?
A. The first cochlear implants were performed in 1961, when Dr. William House implanted the devices in three patients. These devices were made up of a single electrode. Improvements were made to allow for multiple electrode sites, and from 1964 to 1966, procedures were performed using this new technology. In the 1970s, implant technology became even more advanced, and in 1984, the Food and Drug Administration approved the implant process in adults. Candidacy for implants has since expanded to children and to people with lesser degrees of deafness, and advancements have continued to be made in the device’s sophistication and programming. Currently, three cochlear devices are FDA-approved to be implanted in children.
Q. Are there surgical risks with a cochlear implant?
A. While the risks during the surgical procedure are considered minimal, the FDA lists the following as possible risks: injury to the facial nerve, meningitis, cerebrospinal or perilymph fluid leak, infection, blood or fluid collection at the site of surgery, dizziness, tinnitus, taste disturbance, numbness around the ear or reparative granuloma.
Q. What about the risk of meningitis?
A. Because children with cochlear implants are at increased risk for contracting meningitis, the Centers for Disease Control and Prevention recommends that children who receive a cochlear implant follow the recommendations for pneumococcal vaccinations that also apply to other groups at risk.
Q. Can my child have an MRI with a cochlear implant?
A. In some cases, the magnet from the cochlear device must be surgically removed prior an MRI exam. Nevertheless, the new designs of some manufacturers now allow for an MRI with a magnet strength up to 3.0 tesla without surgical removal of the cochlear magnet.
Q. Are there alternatives to cochlear implants?
A. Yes, cochlear implant surgery is considered elective surgery and not medically necessary. Our team believes that amplification and communication choices are a personal decision, and our goal is to ensure that families have information about all of the alternatives in order to make an informed decision. Among the most common options are continued use of hearing aids, reliance upon assistive-listening devices, use of real-time translation and use of a sign language, such as American Sign Language or Cued Speech. For more on cochlear implant alternatives, see the Parent Resources section.
Q. What does a cochlear implant evaluation involve?
A. The cochlear implant evaluation is completed by a multidisciplinary team of surgeons, audiologists, speech-language pathologists, developmental psychologists and an educational liaison. Many factors must be taken into consideration in determining whether a child is a candidate for the procedure. Candidates will most likely receive an audiological evaluation, Auditory Brainstem Evoked Response/Auditory Steady State Response Test, speech perception test battery, balance testing, speech-language evaluation, developmental evaluation, educational evaluation, medical evaluation with CT and MRI scans, vision testing, vaccinations, and genetic testing.
Q. How soon after the procedure will I notice a change in my child? And what should I expect from therapy?
A. It may take six months or longer after the procedure for a child to become used to the new sounds he or she hears. Therapy is an ongoing process, and how soon a change is noticed depends on the age of the child, the needs of the child and the services the child is receiving in school. For the implant to be successful, it is critical that the gains made in therapy be carried over to the home environment.
Q. How many hours a day will my child need to wear the implant?
A. For maximum benefit, the child should wear his or her processor during all waking hours. A hearing child hears every waking minute, and it is important that a cochlear implant child model a hearing child. The equipment also must be checked often to ensure that it is working properly.
Q. Will my child hear normally with a cochlear implant?
A. Hearing is not restored to normal, and the way a person hears with a cochlear implant is different.
Lip reading/sign language may still be necessary for language comprehension, and while your child may be able to understand speech without lip reading, he or she might need to rely on visual cues, which may require your child to look at you to understand speech. Background noise may interfere with hearing, and it may be difficult for your child to follow a conversation when multiple people are talking. Additionally, the farther you child is away from a speaker, the harder it will be to hear or understand — so attempting to have conversations from a different room should be avoided. Your child should be better able to control the loudness of his or her voice and to identify some environmental sounds with training. Your child also might be able to determine if a speaker is male or female.
Q. Does it matter what kind of educational program my child is in? What are my options?
A. Your child’s school performance may improve with a cochlear implant, but it is not a guarantee. There may be other learning difficulties unrelated to hearing loss that may impact educational success. The selection of an optimal educational program can affect how well your child does in school, and a number of options are available for hearing impaired children. These include:
- The Auditory-Oral/Auditory-Verbal Method, which teaches children to use auditory information to learn to speak.
- Manual Communication (American Sign Language), which teaches children to communicate using signs.
- Cued Speech, which teaches children to use hand shapes that are difficult to lip-read.
- Total Communication, which teaches children to combine more than one of these methods at the same time such as the use of manual communication and speaking.
It is suggested that you discuss your communication goals with your child’s educational team. If you choose for your child to have a cochlear implant, auditory and spoken language goals are strongly encouraged.
Q. Will my child be able to listen to music and watch television?
A. Music may not sound normal to your child, and most television programs may be difficult for your child to follow. There are tools such as captioning, as well as a variety of assistive listening devices, which can help your child to understand the information he hears.
Q. Will my child be able to use the telephone?
A. Only about half of people with cochlear implants can use the telephone, even after spending a significant amount of time in therapy. Conversations over the telephone may not be easy. A number of factors contribute to the ability to hear and understand on the phone, which include, but are not limited to, familiarity of the person speaking, the rate of speech, any accents, ambient noise in the environment, etc. It is possible that your child may be able to learn to use the telephone in a limited way. Phone use will be a secondary goal to learning speech and language.