Cochlear Implant Surgery
- A cochlear implant, which is a small electronic device, may be an option when hearing aids do not provide the clarity of sound needed to understand speech and spoken language.
- Early intervention is key. Opportunity for improvement decreases over time as hearing loss worsens. This is especially true for children — an implant may have more benefit the sooner it is provided for a child.
- Rehabilitation and training after surgery are required in order to achieve the best possible hearing ability.
What is a cochlear implant?
A cochlear implant is a small electronic device that electrically stimulates the cochlear nerve (nerve for hearing). The implant has external and internal parts.
The external part sits behind the ear. It picks up sounds with a microphone. It then processes the sound and transmits it to the internal part of the implant.
The internal part is placed under the skin behind the ear during an outpatient surgery. A thin wire and small electrodes lead to the cochlea, which is part of the inner ear. The wire sends signals to the cochlear nerve, which sends sound information to the brain to produce a hearing sensation. Although normal hearing is not restored, with appropriate therapy and practice, the improved hearing experience can mean an increased awareness of sounds in the environment, as well as better communication through easier lip reading and listening.
A cochlear implant may help someone with hearing loss restore or improve the ability to hear and understand speech. A cochlear implant is different than a hearing aid. A hearing aid makes sounds louder but may not significantly improve speech understanding. When a person struggles to understand speech, even with appropriately fitted hearing aids, a cochlear implant should be considered. When the device is tuned appropriately and the recipient is committed to rehabilitation therapy, the -cochlear implant can significantly increase hearing in adults. Cochlear implants in infants and toddlers may help them listen and learn to speak.
Why might I need cochlear implant surgery?
You, your health care provider and an audiologist may consider a cochlear implant if you are experiencing hearing loss and continue to rely heavily on lip reading. Candidates for cochlear implant surgery include individuals who:
- Are experiencing hearing loss and are not helped by hearing aids
- Have hearing in both ears but with poor clarity
- Miss half or more of spoken words, without lip reading, even when wearing hearing aids
- Rely heavily on lip reading, despite wearing hearing aids
In cases of more moderate hearing loss, a partially inserted cochlear implant is used to preserve hearing so that both a hearing aid and the cochlear implant may be used simultaneously in the same ear. In more severe cases of hearing loss, however, a fully inserted cochlear implant is needed to achieve the full benefit of electrical hearing.
How much cochlear implants help varies from person to person. Most individuals note a significant growth in their awareness of sounds within days after their cochlear implant is turned on, which is about four to six weeks after surgery. Speech understanding improves more gradually, with most individuals experiencing the largest improvement within the first six months. The size of this improvement varies considerably between people. Improvements in speech understanding can be aided with auditory, or hearing, therapy after surgery.
Is cochlear implant surgery right for me?
If you are thinking about whether to pursue a cochlear implant now or wait, it is important to know that improvements decrease the longer hearing loss continues. With a successful surgery and rehabilitation, a person may be able to:
- Perceive different sounds, such as footsteps, a door closing or a phone ringing
- Understand speech with less need to lip read
- Understand voices over the telephone
- Watch TV without closed captioning
- Hear music
Before thinking about a cochlear implant, it is important to understand certain facts. These include:
- A cochlear implant requires a period of training and therapy after surgery. During this time, you will learn how to care for the implant. You will also have aural, or hearing, rehabilitation to assist with learning how to interpret the new electrical signals, as well as how to apply these new listening skills to better communicate. This will help to improve your use of the implant. How long and how frequently you have aural rehabilitation depends on your goals and progress.
- Cochlear implants do not restore hearing to normal. In a small minority of people, they may not help with hearing at all.
- You may lose the rest of your natural hearing in the ear where the implant is placed; a hearing aid should be used instead to maintain the remaining natural hearing ability.
- You may need to use new or recharged batteries every day.
- You will need to remove the external part of the implant when bathing or swimming.
- A special procedure may need to be performed before you can undergo an MRI.
- The implant can be damaged during an accident or while playing sports.
- Although a rare occurrence, the implant can fail. In some cases, a new surgery may be needed to replace the implant.
A cochlear implant is not right for everyone. To find out if an implant is right for you:
- You will need to meet with cochlear implant specialists. These may include an audiologist, otologist and speech-language pathologist.
- You may need to meet with a psychologist or other counselor.
- You will have physical exams and hearing tests to assess your hearing loss.
- You will have imaging tests to look at the structure of your ear. These may include X-rays and/or an MRI.
What are the risks of cochlear implant surgery?
Cochlear implant surgery is a safe and well-tolerated procedure. Rarely, as with all surgeries, risks can occur, including:
- Infection in the area of the implant
- Ringing in the ears (tinnitus)
- Dizziness or vertigo
- Numbness around the ear
- Changes in taste
- Dry mouth
- Injury to the facial nerve, which can cause movement problems in the face
- Leakage of spinal fluid
- Infection of the membrane that covers the brain (meningitis)
- Risks of general anesthesia
- Need to have the implant removed because of an infection
There may be other risks, depending upon your medical condition. Be sure to discuss any concerns with your health care provider before the procedure.
What happens during cochlear implant surgery?
Cochlear implant surgery is done in a hospital or clinic. The surgery lasts two to four hours. You are given medication (general anesthesia) to make you sleep during the procedure.
- The surgeon makes a cut behind the ear and then opens the mastoid bone.
- The surgeon identifies the facial nerves and creates an opening between them to access the cochlea, which is then opened. He or she inserts the implant electrodes into the cochlea.
- The surgeon places an electronic device called the receiver under the skin behind the ear, securing it to the skull in this area.
- The incisions are then closed, and you will be moved into the recovery area and watched closely.
- You will be discharged after at least two hours of observation.
What happens after cochlear implant surgery?
When leaving the hospital you will be given instructions on how to care for the incisions. You will also learn how to change dressings and care for your stitches. You may wash your ear as normal after a day or two. A follow-up appointment is made for about one week later or at activation to inspect the incisions and remove the stitches.
You should report increased pain, drainage or fever to your health care provider following the procedure.
You will have some time to heal after the initial surgery before the implant device is turned on or activated. About four to six weeks after the surgery, the external parts of the cochlear implant will be added. These include a microphone and speech processor. At that time, the speech processor is programmed and activated, which causes the internal device to stimulate the cochlear nerve in response to sounds.
You will also learn the basics of using and caring for the implant. You may need to return for several visits over a few days for adjustments. Further fine-tuning will take place over several months. Learning to use a cochlear implant is a gradual process. It will likely require visits with speech-language pathologists and audiologists. With commitment, you can experience an improved quality of life with a cochlear implant.
Cochlear Implant Surgery and Therapy in Children
If the development of spoken language is an important goal for the family of a young child with significant hearing loss, a cochlear implant should be considered.
Equally important to a good cochlear implant surgery is the care provided after surgery, as well as a long-term commitment from the patient and family to learn the new way of listening through a cochlear implant. Weekly auditory rehabilitation should be provided by highly trained professionals who specialize in the area of listening and spoken language. This is critical to guide rehabilitation toward achieving the result desired. This is particularly true for young children who must play catch-up in their development of listening and speaking skills.
There are several factors that influence a child's development of listening and spoken language with a cochlear implant:
- The age at the time of surgery (younger is better)
- Experience with hearing and language prior to surgery
- Consistent rehabilitation therapy and a language-rich home environment
The family should seek a professional team that offers a comprehensive surgical, audiological and rehabilitative program that collaborates with the education options and school of their choice.
Family Receives the Gift of Hearing
When Tracy and Josh Huegel’s children were born, each child had a 25 percent change of being deaf. Four of their five children were either born deaf or became deaf at an early age. As the director of the Johns Hopkins Listening Center, Howard Francis, M.D., performed cochlear implantation surgery on each of the Huegel’s four deaf children.