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What's the difference between a cochlear implant and a hearing aid?
Posted by Bruce Townsend on February 09, 2018
Cochlear implants and hearing aids are both medical devices used to treat sensorineural hearing loss, the most common type of hearing loss.
While both devices treat hearing loss, hearing aids are much more common than cochlear implants. Hearing aids are used to successfully treat varying degrees of hearing loss, from mild to severe. Most people with hearing loss are candidates for and can benefit from hearing aids, which work by amplifying sound frequencies affected by hearing loss.
Cochlear implants are used when hearing aids are insufficient, typically to treat severe-to-profound sensorineural hearing loss due to absent or reduced cochlear hair cell function. Implanted surgically, they work by replacing the function of the damaged cochlea (inner ear) and stimulating the auditory nerve directly.
One cochlear implant for every 16,000 hearing aids
The Food and Drug Administration (FDA) estimated in 2012 that roughly 58,000 adults and 38,000 children use cochlear implants in the USA, compared to the more than 12 million Americans who wear hearing aids. To put those statistics into perspective, for every person wearing a cochlear implant, there are roughly 125 who wear hearing aids. Only half of 1 percent of those seeking treatment for sensorineural hearing loss will be fit with cochlear implants.
How cochlear implants work
A cochlear implant has both internal and external parts. The internal parts — the electrodes and the receiver-stimulator — are implanted by a surgeon. The surgeon places the electrode array in the cochlea, bypassing the damaged hair cells, and the receiver-stimulator is implanted just behind the ear.
The external portion consists of a microphone, processor, and transmitter that sit behind the ear, similar in style to a behind-the-ear hearing aid. The microphone picks up sounds from the environment, and the speech processor selects and arranges those sounds. The transmitter receives signals from the speech processor and converts those into electrical impulses, transmitting them to the surgically implanted electrode array. The electrode array then stimulates the auditory nerve, sending impulses to the brain where they’re interpreted as sounds.
Who is a candidate for a cochlear implant?
Most cochlear implant recipients try hearing aids first, prior to surgery. If hearing aids do not provide maximum benefit, due to reduced cochlear function or poor speech discrimination, cochlear implant surgery is considered. Determining cochlear implant candidacy often involves audiologic testing, medical examination, and imaging studies (X-rays/MRI). Children as young as 12 months can be implanted. Most recipients have profound sensorineural hearing loss or congenital deafness.
Rehabilitation services following implantation are provided by speech language pathologists and audiologists. The cost for one device varies greatly, ranging anywhere from $40,000 to $100,000. Health insurance companies provide varying degrees of benefit for the surgical procedure, device and follow-up services.
This blog was originally published on Starkey.com.