Earlier this year, 3-year-old Abigail and 18-month-old Zoey, had cochlear implant surgery to help restore their ability to sense sound. Their audiologist, Jennifer Ward, took the time to answer a few common questions related to cochlear implants. If you have any additional questions, please leave them in the comments section below.
By Jennifer Ward, Doctor of Audiology
1. What is a cochlear implant? A cochlear implant is a small device that is surgically placed in your cochlea/inner ear. It works by sending impulses directly to your auditory/hearing nerve, which carries signals to your brain. Cochlear implants are designed for children and adults with significant hearing loss who receive little to no benefit from traditional hearing aids.
2. How does a cochlear implant work? A cochlear implant bypasses the damaged portions of the ear and provides electronic impulses directly to the auditory nerve, as compared to a hearing aid which provides amplified acoustic signals to the damaged ear. A cochlear implant consists of an external portion that sits behind the ear and a surgical portion that is placed under the skin and into the cochlea.
The external portion consists of:
The internal portion consists of:
3. How does a cochlear implant work? Cochlear implant candidacy continues to expand based on research showing positive outcomes for those with significant hearing loss as compared to using traditional hearing aids. Cochlear implant criteria suggested by the FDA for children between the ages of 12-24 months is bilateral profound sensorineural hearing loss with no progress noted in speech/language development.
For children between the ages of 2-18 years, the audiometric criteria expands to bilateral severe to profound sensorineural hearing loss and minimal progress or regression in word understanding. For adults, the criteria continues to expand even further to a bilateral moderate to profound sensorineural hearing loss with sentence understanding at less than 50% in the poorer ear and less than 60% in the better ear.
4. Does a cochlear implant restore normal hearing for people who are deaf? A cochlear implant does not restore hearing to normal. However, it provides auditory input that allows most people to appreciate a wide range of sounds; from very soft whispers to loud, abrupt noises. Most people are able to participate in conversations and talk on the telephone without visual cues. However, once the processor is removed, the person is still deaf.
5. What does a cochlear implant sound like? It takes time and a lot of listening practice for the brain to be able to interpret the new sounds. Adults with a memory of sound will often report a mechanical or cartoonish sound quality for the first week, however, shortly after that first week, familiar voices become more like they remember. Just as it takes a year for a normal hearing child to begin saying their first words, it will take children a little while longer to fully integrate this sound and begin using words.
6. How frequently do patients need to come in after cochlear implant surgery? Follow up appointments for both audiologic and aural rehabilitation therapy are integral to success with a cochlear implant. Even then, the road to success is not immediate and can sometimes take up to a year or longer to reach their full potential. In the first 6 months after surgery, weekly aural rehabilitation therapy and between 7-10 audiology visits for programming will be required. After that, younger children continue to return every 6 months, whereas older children and adults will return annually.
7. Are cochlear implants experimental devices? Extensive research has shown the efficacy of cochlear implantation in both adults and children. Cochlear implants have been approved by the FDA for implantation in adults since 1984 and for children since 1989. As of December 2012, the FDA reports that there are over 324,000 people worldwide that have been implanted with cochlear implants. In the USA alone over 58,000 adults and 38,000 children have received cochlear implants. Research has shown that children who receive cochlear implants prior to 18 months of age, followed by intensive therapy, often develop spoken language at a rate similar to normal hearing peers and they often do well in mainstream school settings.
8. Are there risks associated with cochlear implant surgery? However, they are quite rare. As with any surgery there are risks of anesthesia; but a cochlear implant surgery can also cause some of the following: dizziness, tinnitus, taste disturbance, facial nerve palsy, cerebral spinal fluid and/or perilymph leaks, numbness around incision site, meningitis and infection of the skin/wound. Again, these are very rare and most people experience none of these.
9. Should everyone consider a cochlear implant? A cochlear implant is not for everyone. It is a very personal decision that requires multiple appointments to determine if you are a candidate or not. Each patient/family should choose what they think is best for their family and lifestyle. Typically, patients/families that are interested in cochlear implantation are those that have chosen to use listening and spoken language as their primary mode of communication. However, some patients/families will also use a form of manual communication.
There are multiple factors that can affect your outcome with a cochlear implant including age and duration of deafness, use of amplification, intervention options and consistent use of the external sound processor.
10. What role does sign language play for individuals with cochlear implants? Sign language can help reinforce concepts and sounds when learning spoken language. Many people never choose to use sign language and others will choose to continue using sign language, even with a cochlear implant, for full communication abilities.
11. What long-term effects do cochlear implants have? Positive long-term effects of cochlear implants include better access to audibility which leads to improved communication, increased use of the telephone and ability to watch television and for some enjoyment of music that they have not heard for many years.
Cochlear implants have now been implanted in people for over 30 years with minimal negative long-term effects. With any implantable device, there is a chance that it can fail which would lead to explanation and re-implantation if the patient/family chose to do so. Since children are so young when implanted, it is likely that in their lifetime, technological advances would possibly warrant another surgery.