Listen up, everybody!
A friend of mine is an award-winning Toastmaster who attributes much of her successful speechifying to her cochlear implant. J, as I will call her, was born with a normal sense of hearing but lost that natural ability after a severe illness in her teens. Hearing loss was devasting, according to J.
My first introduction to cochlear implant technology happened at a weekly Toastmasters meeting when every speaker was provided with a special microphone on a lanyard with clever quick-release magnetic fasteners so that J could listen in on all the speeches and participate in feedback evaluations and discussions.
J was a guest speaker and shared her life story with us as we sat, enthralled and admiring of this woman who became an organizer and inspirator in the leading international volunteer non-profit whose mission is to promote better communication and leadership despite her physical disability. Needless to say, J is now a heartfelt advocate for this truly amazing and helpful technology.
After sound waves enter the ear canal they reach the eardrum which passes the vibrations through the tiny bones in the middle ear, called ossicles. The inner ear, termed the cochlea, is shaped like a snail and lined with thousands of tiny hair cells.
It is these sensitive, fine hair cells that change the sound waves into electrical signals for transmission to the brain through the cochlear (hearing) nerve. The brain then alerts you that you are hearing a sound and interprets what that sound is.
People who like loud music or work around heavy machinery or power tools take note: each one of those teeny tiny hair cells has a small patch of stereocilia sticking up out of the top it. Stereocilia are actin-based protrusions on auditory and inner ear sensory cells that are necessary for hearing and balance. (Actin is a family of globular multi-functional proteins that form microfilaments, tiny hair-like structures.)
Sound rocks the stereocilia back and forth. Loud sounds can bend or even break the stereocilia, causing the hair cell to die and rendering it inoperative. No more physical wave translation to electrical signals to the brain to your consciousness.
Once a human hair cell dies, it is gone for good and will never grow back. The hair cells responsible for handling high frequencies are the most fragile and easily damaged. It is common for people with hearing loss due to exposure to loud sounds to have impaired hearing in the high-frequency ranges such as crickets, birds chirping or even women’s high-pitched voices.
A cochlear implant is a small electronic device that partially restores hearing by bypassing damaged portions of the ear to deliver electrical impulses to the cochlear nerve. An implant has external and internal parts:
The external part is a sound processor which rests behind the ear where its microphone picks up sounds, processes them, and transmits them to the internal part of the implant.
The internal part is a sound receiver implanted behind the ear subcutaneously (under the skin) during an outpatient surgery. A thin wire in the receiver earpiece passes the signals to electrodes implanted in the cochlea for normal transmission to the brain to produce the sensation of hearing.
A cochlear implant can’t restore hearing to normal levels but is far better than nothing, according to my gal pal J, who uses lip-reading to help her understand the spoken word. She, like many others experiencing hearing loss, has trouble understanding spoken words when someone’s back is turned.
Cochlear implants are appropriate for people who have severe hearing loss from inner-ear damage that can’t be resolved with hearing aids which serve merely to amplify sound.
Specialists can provide therapy and, when the device is well-tuned and the patient commits to performing the recommended rehabilitation therapy, a cochlear implant can significantly increase hearing in adults. It does take time, training, and patience to learn to interpret the signals received from a cochlear implant.
However, most people with cochlear implants make considerable gains in understanding speech by the first anniversary of their implant operation.
Babies and toddlers having trouble listening and learning to speak have also benefited from cochlear implants in both ears (bilateral).
There are eligibility requirements for receiving a cochlear implant:
- Hearing loss that is so severe it interrupts spoken communication
- Limited benefit from hearing aids as determined by specialized hearing tests
- No medical conditions or factors that increase the risks associated with cochlear implants
- High motivation to participate in rehabilitation sessions and to be part of the hearing world
- Clear understanding of what cochlear implants can and can’t do for hearing
There are also some medical risks to getting a cochlear implant, including losing the rest of your hearing in that ear. Meningitis (brain and spinal cord inflammation) can also be a post-surgical problem in children who are typically vaccinated for the disease before undergoing the hospital procedure.
The decision to get hearing help from a cochlear implant is an important one that can drastically improve the quality of life for someone like my friend J who was adrift in a soundless sea.