Feb 2019 Hearing Loss Resources
“IF YOU QUALIFY FOR A COCHLEAR IMPLANT (CI) BUT DO NOT HAVE ONE, PLEASE INDICATE REASONS YOU HAVE NOT PURSUED.”
This question was one of three dozen on hearing conditions posed in Hearing Health Foundation’s 2017 Reader Survey. More than 2,300 people responded. The CI question above gave the following answers, in order of popularity: 1) not convinced of improvement, 2) surgery complications, 3) waiting for biological cure, 4) concerns about sound quality, 5) cosmetic, and 6) fear of discomfort.
Although “other” with a fill-in option was offered, age did not appear to be a primary concern. In fact, many older adults with severe to profound hearing loss whose hearing aids are no longer are beneficial have found success with CIs. Part of the survey’s purpose is to better understand the needs of our community of readers and supporters, and so, as cochlear implant surgeons, we wanted to address these concerns.
Not convinced of improvement
All CI centres, including ours at Vanderbilt University Medical Centre, perform extensive presurgical testing to determine if a CI is the right option for a patient, versus the continued use of hearing aids. The testing, based on data and experience, answers this question with an incredible degree of accuracy. Our goal is to reach a level of hearing that dramatically outperforms the best hearing aid outcomes for a given individual. Expectations are much higher than this, however, and it is extremely rare for a patient who is wearing their implant full-time not to experience much better preoperative hearing performance. The benefit has been so pronounced that Vanderbilt and other CI centres are working to expand implantation criteria so that this technology reaches people with milder forms of hearing loss.
Cochlear implantation has one of the most favourable risk–benefit ratios of any surgical procedure in the U.S., offering significant communicative benefit while incurring little risk. Our centre performs nearly 300 implants per year, and we monitor and track all procedures, outcomes, and complications. As with any operation your surgical team will provide a list of potential complications in order to be comprehensive, but the actual incidence of CI surgery complications ranges from under 1 percent to 3 percent. If any do occur, they are considered minor and temporary, such as postoperative taste disturbances and dizziness. At most CI centres, implantation is completed as an outpatient procedure and generally performed in 1 to 1.5 hours. We recently completed cochlear implantation on a 96-year-old patient who went home on the same day of surgery.
Waiting on a biological cure
The field of hearing restoration through hair cell regeneration—some of which is being conducted by HHF scientists, through the Hearing Restoration Project—is still in its earliest phases. While there have been exciting advances in gene therapy, current technology via cochlear implants can provide people with severe to profound hearing loss immediate access to sound, and all the benefits that this brings. In addition, improved success with CIs is linked to implantation that occurs closer to the onset of hearing loss, as auditory pathways in the brain need to be stimulated or they weaken. Otherwise the resulting permanent changes in the brain’s auditory centres may limit the ability of a patient to hear, even with a perfectly intact cochlea.
Concern about sound quality
Despite CIs being a mechanical device, the voice sound quality has the potential to be no less electronic sounding than that from a telephone, computer, or television. Often the abnormal sound is due to the stimulation of an ear that hasn't heard for many years (or an ear that has never heard). If this occurs, it typically dissipates with continued use of the CI and the stimulation of auditory pathways. Signal processing technology also continues to advance at a rapid rate, allowing for personalised programming for the best hearing outcomes, and—especially with any neural changes with age—programming is important to do at regular intervals.
The thin internal portion of the CI is designed to sit flush with the skull and is not visible. The visible external components (the battery, sound processor, microphone, and transmitting coil) mostly fit behind the ear, not much larger than a standard behind-the-ear hearing aid. The latest sound processors are self-contained in a single unit about the size of a half dollar coin. These “off-the-ear” processors do not have an over-the-ear component, but rest directly over the magnet that is behind the ear and within the hairline. Eventually we expect that all implanted systems will be compatible with these smaller, off-the-ear processors, and nanotechnology and battery miniaturisation will further reduce processor size. Plus the boom in wearable consumer technology makes visible devices even more mainstream!
Fear of discomfort
Implantation incisions behind the ear heal quickly, and the drilling of the bone required to place the
implant is a simple mastoidectomy. It is a component of most ear procedures and is not painful. Our centre performs over 1,200 mastoidectomies per year across various different ear procedures. Postoperative discomfort is a rare complication and easily managed with over-the-counter medications.
Do You Qualify?
If you have a hearing loss that prevents you from talking on the phone without visual cues (such as needing video calls or caption calling); are unable to understand television programs without closed captioning; and/or are actively avoiding large group gatherings for fear of conversational difficulty, talk to your hearing healthcare professional to see if you may be a CI candidate. CIs are the most successful sensory restoration prostheses to date and have been successfully placed in more than half a million individuals worldwide. The wonders of this technology vastly improve hearing, speech understanding, and overall quality of life.