Opponents of cochlear implants, or CI skeptics, or even those who are neutral but uninformed often parrot the lines that “Some people just don’t do well with cochlear implants.” They say, “Not everyone gets the same results.” I’ll agree with them on those statements — they’re right. Unfortunately, we do still see large variability in the speech, language, and listening outcomes of users of cochlear implants. Where the critics have it wrong, however, is that they portray these differences in outcome as largely due to chance — unexplainable phenomena that no one can predict or prevent. Myths continue to persist that the outcomes of cochlear implantation are “uncertain,” “risky,” or “a gamble.”
In truth, it is a rare, rare case where cochlear implant “failure” happens with no discernible cause. This is not a game of chance where you might just be the unlucky patient who has inexplicably bad results. Far from it. Yes, there are issues that cause people to have poorer outcomes with the CI, but we know these factors and how to fix them. The more accurate we are about describing and remedying these issues, the better off we will be.
Research has identified many of the factors that contribute to success with a cochlear implant, they’re not a mystery:
If implanted later, good access to sound (either with natural hearing or hearing aids) prior to surgery.
Short period of auditory deprivation pre-CI.
Intact auditory nerves and cochlear anatomy (patients with abnormal nerves or anatomy can still have good results, but it’s less straightforward with these cases)
Average cognitive abilities and absence of other complicating conditions (this is not to say that people with additional disabilities cannot benefit from CIs — they absolutely can! — just that it’s not as easy as someone who is “vanilla deaf”)
CI wear time all waking hours (lots of auditory input)
For more information, see: Niparko et al., 2010, Geers, 2006, Green et al., 2005, Geers, 2004, Nikolopoul0s et al., 2004, Spencer, 2004, Friedland et al., 2003, Dowell et al., 2002, Geers, 2002, Pyman et al., 2000, van Dijk et al., 1999, Rubinstein et al., 1999, along with many, many others.
So how do we explain less-than-optimal outcomes with cochlear implants?
Sometimes, it’s a hard (or soft) equipment failure. Cochlear implants are electronic devices, after all. They’re man-made, they’re fallible, and they do fail. Though CIs are well-designed and rigorously tested, just like your car or your toaster or your television will sometimes break down, they will, too (of course, they’re held to much higher standards, as they should be, because they’re implanted in your body). I think it’s very important that we as professionals are honest about this to our patients. Though the devices are designed to last a lifetime, it’s really a matter of when, not if, they will eventually need to be replaced. For most people, the prospect of failure and re-implantation is nothing compared to the access to sound, communication, and brain development an implant provides.
At times, the failure is “hard,” meaning there is something identifiably wrong with the internal implant that can be seen using objective measures (impedance testing, a CT scan, etc.). A “soft” failure refers to symptoms that the user may be able to perceive (buzzing or crackling sounds, sub-optimal hearing performance) but cannot be objectively measured. A third possibility (that’s really just a breakdown of equipment, not a true failure) is problems with the external device — a bad cable, scrambled processor, or blocked microphone. However, detecting and fixing these issues requires a cochlear implant user who can report them and/or parents/caregivers who check the equipment daily, and hearing healthcare professionals (audiologist, auditory verbal therapist, surgeon, etc.) who are vigilant about changes in the patient’s hearing and quick to move when a problem is detected.
Audiological issues. A good pediatric audiologist is worth her weight in gold. (Adult audiologists, too! It’s just that correctly mapping a child is much trickier.) It is my opinion that a large, large percentage of people who are not doing well with their cochlear implants are either improperly or inadequately mapped. Either the MAP is just completely off-base or the person is really under-amplified and under-utilizing their device. There are sadly very few audiologists who recognize the gold standard of a quality MAP (in short, hearing at 15-20dB across the board through at least 6000Hz with speech perception of quiet and loud speech and speech in noise scores 90%+) and work to get their patients there.
Unrealistic expectations can also lead a person to report their implant a “failure.” It’s important to consider your/your child’s hearing and communication history when deciding what is an appropriate result. You’ve got to consider that cochlear implantation is not really about the ears, it’s about the brain.
So what if you reach a point and you or your child aren’t doing well with the cochlear implant? HERE is a list of troubleshooting suggestions that can help. In most of these cases, it’s not the implant that’s broken, it’s the input. Remember that success with a CI is 10% hardware (the device and having it function correctly) and 90% software (the rehabilitation effort you put in).
The last underlying issue that I think contributes to the myth that CIs are a gamble where some of them mysteriously “just don’t work” is that the people making those statements are a) speaking about anecdotes, not evidence and b) drawing from a biased sample. If you spend the vast majority of your time in a signing school for children with hearing loss, where there is minimal auditory input and emphasis on listening and spoken language, then of course the students you see with CIs are going to be non-users or poorer users of the device. The children who are doing well with their cochlear implants, by and large, are not in these kinds of educational placements. They’re mainstreamed and basically “disappear” into their everyday environment. If you’re an adult heavily involved in the signing Deaf community, you’ll probably encounter many people who are unhappy with their CIs — it goes back to the 10% hardware, 90% software rule — these are simply not environments that provide the “software” for CI success.