A cochlear implant is a small, electronic device that can partially restore listening ability in people that have severe inner ear damage. In people with sensorineural hearing loss, the hair cells contained within the fluid-filled cochlea may be damaged. The hair cells function by transmitting sounds received via the outer ear to the auditory nerve. A hearing aid can help by amplifying external sounds, but if the hair cells are too damaged, then a person with hearing loss will receive little to no benefit from a hearing aid. In these cases, a cochlear implant may be able to help.
A cochlear implant helps people with severely damaged hair cells because the implant bypasses the damaged portion of the ear and transmits sound directly to the auditory nerve. The implant consists of both surgically implanted internal and external components. An external microphone receives sound from the environment, such as speech, and sends it to a sound processor. The sound processor then transforms the sounds into electrical impulses. Both the microphone and sound processor sit behind the ear. They are connected by a small wire to a transmitter that sits directly on the skull. The transmitter is attached to the skull via a magnet and transmits the electrical impulses to the surgically implanted receiver. From the receiver, the impulses travel to electrodes implanted in the inner ear, where they stimulate the auditory nerve; the brain then interprets these impulses as sound.
A person with a cochlear implant does not hear sounds as someone with normal hearing would hear them, and as such, a cochlear implant does not restore hearing in a deaf or nearly deaf person. Instead, it simulates hearing by stimulating the auditory nerve, and therefore it takes time, rehabilitation, and practice for someone with a cochlear implant to learn to interpret the signals received.
A cochlear implant may not be the right choice for everyone. They have pros and cons that you should consider if you are thinking about getting a cochlear implant to help with your severe hearing loss.
Pro: Cochlear Implants Allow Deaf People To Hear
Minimally, a cochlear implant should enable deaf people or people who could formerly hear to hear and perceive sounds. In deaf people, this will help improve their skills in reading lips because they will be able to now hear speech and other environmental sounds. Results often exceed the minimum, and a lot of implant recipients can hear and understand speech with no visual cues. They sometimes can even learn to use the telephone.
This will enable people with cochlear implants to follow conversations more easily and improve communication with loved ones. Many users report being able to hear sounds that they could no longer hear, even softer sounds, such as footsteps and rustling leaves. Cochlear implant users are also often able to hear and appreciate music, some for the very first time. The ability of someone with cochlear implants to move around outside safely will improve, as they will be able to hear and perceive potential dangers such as sirens and other warning sounds.
Pro: Opening Up New Possibilities for Deaf Children
Sensorineural hearing loss affects one out of every 1,000 children born, many children being born completely deaf. The inability to hear at such a young age can have a serious effect on speech and language development. A cochlear implant can significantly help children learn to communicate, and develop listening and spoken language skills that they might otherwise be unable to develop. The benefits of a cochlear implant may be such that a child requires less assistive technology and may be able to perform better in the classroom. These improvements in hearing and speech early in life will help children as they age and provide them with career opportunities they may not otherwise have had.
Pro: Giving Older Patients Their Social Lives Back
Hearing loss is a difficult problem, because many people experience it but we can’t see it. This invisible disability causes sufferers to become isolated from loved ones and society in general because as the hearing loss worsens, they become less and less able to communicate effectively. A hearing aid may help some people to hear and engage in conversations, but hearing loss may worsen to the point where even hearing aids no longer help. The social isolation brought on by hearing loss carries with it the danger of other debilitating symptoms, such as dementia and depression.
A cochlear implant can often greatly assist people with severe hearing loss. Even if the user must rely on lip reading or sign language, a cochlear implant can enhance speech perception and communication. Thus, cochlear implant users can maintain social activity and engagement, which is important for mental health and well-being.
Con: Cochlear Implants are Expensive
Hearing aids are already expensive, with an average cost of $1,200 to $3,500. For a technology that assists people when hearing aids no longer can, the price is going to be high. The average cost of a cochlear implant for one ear ranges from $30,000 to $50,000, but can be as high as $100,000. Fortunately, most major health insurance plans, such as Medicare, Medicaid, and the Veterans Administration, provide coverage for cochlear implants.
Con: Invasive Surgery and Potential Side Effects
Unlike a hearing aid, which can be easily installed and removed by the user, a cochlear implant requires invasive surgery to have the receiver and electrodes implanted into the recipient’s cochlea and mastoid bone. Although the surgery only lasts two to four hours, it is not without risks, especially because the surgery involves facial muscles and nerves, the skull, and the inner ear. Some potential risks or side effects include:
- Bleeding and/or swelling
- Infection at the implantation site
- Development of tinnitus, dizziness, or vertigo
- Changes in taste or dry mouth
- Injury to the facial nerve, which can cause movement problems in the face or numbness
- Infection of the membrane that covers the brain (meningitis)
- Risks of general anesthesia
Con: Cochlear Implants Require a Long-term Investment for Good Results
Once the surgery is over and the individual has received the cochlear implant, that’s really just the beginning. The hearing does not improve immediately, like it may with a hearing aid. The recipient will have to wait several weeks for the incisions to heal before receiving the external portion of the device. Once it has been attached, the user will have to return to the audiologist several times to adjust the implant to the specific needs of the user and for optimal performance. Further refinement and adjustments will take place over several months.
It’s important to keep in mind that cochlear implants do not restore hearing, they give the users a sensation of sound. Because of this, there is a long learning curve, as the recipient begins to understand and interpret what the new signals mean. This will require potentially weekly sessions with speech-language pathologists and audiologists and much practice. For children born deaf it may be especially difficult because they need to develop an understanding of auditory information that they’ve never had before. It is a commitment that needs to be considered before moving forward with cochlear implants.
Some other long-term factors with cochlear implants to consider:
- The batteries will most likely need to be replaced or charged every day
- The external portion (unless waterproof) will need to be removed before bathing or swimming
- Cochlear implants affect MRIs, so a special procedure will need to be done
- The implant is susceptible to damage during physical activity
- Implants can fail (albeit rarely) and require surgery to remove or replace them
Con: Desired Outcome is Not Guaranteed
The success of a cochlear implant can not be predicted- some people have great success and are able to communicate with no visual aides, watch TV, listen to music. For some, there is little change or benefit. For the majority of cochlear implant recipients, the implants provide a greater ability to perceive and process sound. Because every person is unique, there is no way to predict that desired outcomes will be met, and not all users receive the same benefit.