Borderline Cochlear Implant Candidates

For many who receive a CI, the choice is clear-cut: hearing aids simply do not provide sufficient benefit for language and listening to people with profound hearing loss when compared to the performance of a cochlear implant.  But what about hearing aid users who are doing “well enough” with their current technology, but are on the fence about whether or not a cochlear implant is the right option for them?

 This can be a very tricky decision, because there’s no going back.  Even though today’s cochlear implantation techniques have improved and it is often possible to preserve residual hearing, going back to a hearing aid after receiving a cochlear implant is not as simple as trying on a new pair of glasses.  That said, we are seeing some really superior results in patients who initially would never have been considered as CI candidates, but, once they received their cochlear implants, are showing remarkable improvements (see links at the end of this article)^1,2.

HOW do you know when it might be time to make the leap to a cochlear implant (or two) for yourself or your child¹?

• Aided thresholds are not at the TOP of the “speech banana.”  Only hearing “somewhere” inside the speech banana is not enough.  If your thresholds make a line through the middle of that region, you’re still missing a significant amount of speech sound information — and that’s at conversational levels!  Imagine what you/your child are missing in soft speech.

• Aided speech perception scores for soft speech (30 dB SPL) and conversational speech (50dB SPL) in quiet and in noise are not in the excellent range (90% +).  Jane Madell is famous for saying of speech perception score, “If it wouldn’t be good on a math test, it’s not good on a speech perception test.”  Scores of 50, 60, 70% etc. mean that your child, in sound booth-quality conditions, with no other distractions, is still having to guess nearly half the time.  That’s no way to go through life — it’s tough, it’s exhausting, and, for developing language learners, it’s going to lead to a real uphill battle toward language competence.

• Insufficient progress even with appropriate auditory-based therapy.  If a hearing aid user is enrolled in listening and spoken language therapy with an experienced professional, devices are worn all waking hours, and the family is committed to home carry-over but is still not progressing at the expected rate, it may be time to consider a change in technology.

• Lack of access to all speech sounds.  If your/your child’s hearing aids are doing “pretty well” in general, but you still cannot hear soft, high-frequency speech sounds like f, sh, th, it may be time to switch.  This is especially true and VERY crucial for young children who are just developing speech.  If they can’t hear it to imitate it, they’re going to have to learn to speak by seeing — a very ineffective method that can lead to unnatural production and poorer voice quality (remember, we only SPEAK as well as we HEAR).

• It’s important to remember that FDA guidelines are just that: guidelines.  They are not laws and surgeons have leeway to use their professional judgment to provide cochlear implants “off label” to patients who they feel would benefit (just as physicians can prescribe medicines “off label” to benefit patients for reasons other than their intended use).  Remember also that the FDA criteria for CIs are years old at the point, while cochlear implant technology is progressing every day.  The FDA guidelines have not kept up with our improvements in CI technology and rehabilitation.

WHEN is the right time to make the switch?  My bias is: the sooner the better!  Once an appropriate battery of auditory and speech-language tests have been done to establish that YES, a cochlear implant is a good option, the time to move is NOW.  For adults who are long-term hearing aid users, why wait to reap the benefits in quality of life and ease of communication that the CI can offer?  For children, every month without full, complete access to sound is taking precious time away from a brain ready to soak up listening and language.  Going back and forth and delaying a CI will only make the rehabilitation harder when that ear, used to dealing with the sound from a hearing aid, has to re-learn how to hear with a cochlear implant.

WHO should you consult?  If you feel that a cochlear implant could benefit you or your child, the first step is to speak with your audiologist.  If he/she is primarily experienced in hearing aids, it may be time to seek a second opinion.  You want an audiologist with plenty of cochlear implant experience who is an aggressive advocate for his patients.  Studies also show that borderline candidates who work with otolaryngologists whose primary focus is cochlear implantation receive cochlear implants more frequently than patients whose ENTs are  generalists².

Speaking from clinical experience, I have seen many children who are borderline candidates for any number of reasons (speech perception is “too good” with hearing aids, auditory neuropathy cases, kids who are perceived as “great performers” with their hearing aids) go on to receive cochlear implants and do remarkably well with them.  We must remember that hearing aids simply amplify sound but still drive that sound through a fundamentally compromised system (the cochlea of someone with sensorineural hearing loss).  Even if the sound is louder, that cochlea still has damage and is not performing 100%.  And when we amplify sounds loud enough, we often run into issues with feedback and distorting the sound.  For these children, moving to a cochlear implant (or two) has made a world of difference.  Anecdotes are not evidence, though, and more research is needed to support our clinical judgment that, for many borderline hearing aid users, the cochlear implant is the right choice.

REFERENCES

¹ Madell, J. R. and Gifford, R.  Expanding Criteria for Cochlear Implantation.  AudiologyNOW 2010.

² Tobey, E. (2010, February 16). The Changing Landscape of Pediatric Cochlear Implantation : Outcomes Influence Eligibility Criteria. The ASHA Leader.