Cochlear implants are surgically implanted devices that replace the function of the inner ear, or cochlea, for people with severe to profound hearing loss. Cochlear implants do not restore normal hearing but they do give people more awareness of sounds. Unlike hearing aids, which amplify sounds, a cochlear implant bypasses damaged portions of the inner ear to deliver sound signals electronically to the hearing (auditory) nerve. These signals stimulate the auditory nerve, which then directs the signal to the brain. The brain interprets those signals as sounds, although these sounds aren’t like normal hearing because they are electrical stimulation. It takes practice and persistence to learn to interpret the signals received from a cochlear implant. Within six months to a year of use, most people with cochlear implants have made good progress in understanding speech and are following conversation better than with their hearing aids.
How Does a Cochlear Implant Work?
A person with a cochlear implant wears a special sound processor behind the ear or against the head above the ear. The microphones on the processor pick up sounds and convert them into electrical impulses which are sent to the internal electrode device in the inner ear. Imagine a piano keyboard, which goes from low pitches, like a fog horn on the left side of the keyboard, to the high pitches, like a bird whistle on the right side of the keyboard. The cochlea is just like this, except the high pitches are represented at the base of the snail shape. The implanted electrode curls around the snail shape of the cochlea and stimulates the different areas of the inner ear that represent low, middle and high pitched sounds. Hearing goes from acoustic (sound waves in the air) picked up by the outside processor to electrical stimulation through the electrode. Sound from cochlear implants is very different from hearing aids, and sometimes is described as electrical beeps or robotic speech. Over time the brain learns to recognize these sounds and they become more natural.
Who Gets Cochlear Implants?
In cases where the best fit hearing aids are not enough to follow conversation, or hear on the phone, cochlear implants can help those with severe to profound hearing loss detect and often understand sounds around them. Babies born with severe hearing loss as well as older adults in their 90’s can all be helped by cochlear implants. Babies and children benefit by having full access to sounds around them so that they can develop speech and language skills.
Often people who have worn hearing aids for many years find that they are having greater difficulty hearing, especially in groups or areas with background noise. When hearing levels reach the severe hearing loss range, and speech clarity is reduced, a cochlear implant may be recommended.
Audiologists perform special hearing tests to see if a person is a candidate for cochlear implants. Testing goes beyond the standard audiogram and speech understanding tests to include testing with hearing aids and testing words and sentences in noise.
How Does Someone Receive A Cochlear Implant?
The first step to determine if a cochlear implant would be beneficial is to have a cochlear implant evaluation by an audiologist. If the results suggest a cochlear implant may help, then the next step is to meet with the ear surgeon and their team to have xrays of the inner ear completed along with a medical evaluation. The costs of cochlear implant surgery and the processor are usually covered by medical insurance. The procedure is typically outpatient. Once the ear has healed, in about a month, the audiologist activates the cochlear implant and creates a special program for the implant. Several sessions are needed to adjust the implant. Practice and persistence are necessary to get used to the new way of hearing.
What Does The Future Hold For Cochlear Implants?
Cochlear implants are continually improving because of all the rapid advances in digital technology. Features have recently been added to make communication easier, like direct bluetooth streaming to cell phones and computers. Rechargeable batteries and smaller processors make cochlear implants less conspicuous, easier to use, and more comfortable. Candidacy, or who will benefit from cochlear implants, is also evolving as the technology advances. In the future, cochlear implants will restore communication and improve quality of life for even more people with hearing loss.
Why Might I Need A Cochlear Implant?
If your hearing aids are no longer helping you communicate easily in daily activities, cochlear implants may be the next step in allowing you to stay connected to those you love. When the inner ear, or nerve of hearing, is not working properly to send clear signals to the brain, a cochlear implant may provide better hearing even when compared to the best fit hearing aids.
Many people with severe to profound hearing loss are unable to communicate unless they can see the speaker and read their lips. They may not be aware of sounds around them and are unable to monitor signals like a doorbell, smoke alarm and alarm clock. Using a cochlear implant can restore sound awareness for alarms and provide sound perception and often greater understanding of speech.
What Happens During Cochlear Implant Surgery?
A cochlear implant surgery procedure is performed under general anesthesia. The surgeon will make a cut (incision) behind your ear, and form a small hole in the portion of skull bone (mastoid) where the internal device rests. The surgeon will then create a small opening in the cochlea in order to thread the electrode of the internal device through the curves of the cochlea. The skin incision is stitched closed so that the internal device is under your skin. Most people go home the same day, or the next day, and return for a postoperative appointment within a week. The surgeon will tell you how long you need to rest for best healing. Often people are able to return to most activities within a few weeks.
What Happens After The Cochlear Implant Procedure?
The cochlear implant is turned on anywhere from 3-4 weeks after the surgery to allow the ear to heal. The audiologist will test the device to be sure the internal parts are working and program the sound settings to get the person started.
For babies and young children the audiologist will work closely with the parents, educational specialists and a speech-language pathologist. The team works together to support the child’s adjustment to the device and to be sure the child is getting the most out of it. Often early intervention services come directly to the home to help the parents provide extra stimulation and enrichment activities which assist with listening, speech and language development.
For adults, sound will be very different from what they may have heard with hearing aids. The brain needs time and lots of practice to identify the new sounds. Just like people have physical therapy and home exercises after a knee replacement, adults need several appointments with the audiologist for adjustments as their brain gets used to the new sounds. At these appointments they will be provided a plan for listening therapy and home practice. People who are really motivated to practice and wear the implants full time, all of their waking hours, will have the best outcomes. Some people are even able to have a phone conversation with a familiar person, something they could never have done with their hearing aid. Most people report that after the first year they notice big improvements in their ability to follow conversations. They express that, as a result of the cochlear implant, they are experiencing an improved quality of life.
