Like any big decision, getting a cochlear implant involves just a little bit of a leap of faith. No matter how much you research, there is no way to know 100% what will happen with the surgery, activation, or rehabilitation. By and large, results are fantastic, but how can you know what to expect for your/your child’s speech, language, and listening progress? Regardless of the individual candidate’s circumstances, a few rules apply across all situations: It’s All About the Brain, It’s All About Time, and It’s All About the Therapy.
It’s All About the Brain. A cochlear implant is simply a tool to get sound to the brain by replacing a damaged auditory system. No matter how well the CI is functioning, if it is pushing sound to a brain that has not had the benefit of auditory development, results will be limited. This is why adult CI candidates who have either grown up with typical hearing or been good hearing aid users throughout their life (keeping their auditory brain stimulated) tend to have better results. Their brains are already accustomed to listening, the CI just gives them more and clearer sound with which to work. Another question to ask is, “What kind of brain are we working with?” Other than the candidates auditory experiences, what are her strengths and limitations? Are there other cognitive challenges or disabilities that may affect her ability to learn to listen and talk?
It’s All About Time. Timing is everything. For adults, it matters how long ago the hearing loss began and how long the brain has gone without sound. For children, time is of the essence as any time without the full access to sound provided by a cochlear implant (for children who are not receiving enough benefit from hearing aids) is language, listening, and learning time lost. Progress, too, can be measured in time. On the one hand, we must take into account listening age when we consider how a CI recipient is performing. The brain needs time to listen before we expect auditory performance. Just because a child is chronologically five years old doesn’t mean we would expect her to be achieving five year old skills if her “ears” are only a year old. Just as typically hearing infants listen for a year before they begin to say their first words, so too do young CI recipients require a “listening year” of input to build the foundation for later output (speech and language). Likewise, adult recipients also require a period of listening practice to adjust to the new input their brain is receiving, even if they have previous experience with sound. On the other hand, we must aim for progress that at a rate of greater than month-for-month. If a child receives a cochlear implant at X months and is making only one month’s progress in a month’s time, he will always be X months behind his chronological age peers. We need faster progress to close the gap. Wear time is also important. If a CI user is only wearing their device a few hours a day, that is no where near the all-waking-hours auditory practice necessary to make progress.
It’s All About theTherapy. Auditory-based therapy is key to getting the most out of a cochlear implant for both pediatric and adult recipients. For a child, therapy should begin at the identification of hearing loss, even if hearing aids aren’t providing enough input and cochlear implants are inevitable. Why? A variety of reasons. First, even if the child is only getting the tiniest benefit from hearing aids, they’re still stimulating that residual hearing and growing that auditory brain. Auditory-Verbal Therapy capitalizes on this and helps the family help their baby get every last drop of hearing out of those hearing aids before cochlear implant surgery (see more HERE). Second, therapy before the cochlear implant helps the child learn therapy routines and the parents become comfortable with therapy techniques so they can really hit the ground running after activation, rather than start from scratch and waste precious hearing time. For adults who receive a CI, aural rehabilitation therapy is also crucial to re-train a brain that is used to a different type of sound. In both cases, it’s not just therapy that matters, but also the type of therapy. Auditory-Verbal Therapy provided by a Listening and Spoken Language Specialist includes a focus on building skills through the developmental process of listening and mirrors the way that typically hearing people acquire speech and language skills. Therapy that focuses on manual communication methods or learning speech through visual cues is like going to a physical therapist to work your legs when your arm is broken — it’s not targeting the auditory part of the brain.
Here are some scenarios to consider, keeping in mind that, because of the factors listed above, each patient’s experience will vary:
Post-lingually deafened adult receiving a cochlear implant after a brief period of hearing aid use in adulthood: A CI candidate who grew up and learned to listen and talk without hearing loss, lost hearing as an adult, and kept his auditory brain active by using a hearing aid to stimulate residual hearing until receiving a cochlear implant often does very well and very quickly after cochlear implant activation.
Pre-lingually deafened adult who has been a lifelong hearing aid user and oral communicator: This type of candidate often does well also. Receiving a cochlear implant gives this person access to far more sound than they ever received with their hearing aid, and, with practice, can help them make the leap from relying on speechreading to being able to understand speech without visual supports.
Pre-lingually deafened adult who has not used hearing aids AND/OR who has been a visual communicator: This patient’s brain has not been used to processing auditory input for communication. While a cochlear implant will most likely provide a huge quality of life and safety increase in allowing this person to hear and appreciate environmental sounds and perhaps familiar speech, a lifetime without auditory stimulation leads to a brain that will not easily make the leap to being a fully listening and spoken language communicator. That’s not to say that these patients don’t benefit form a cochlear implant — they do! — but to expect the CI to make this person a listener overnight is unrealistic given their lack of prior auditory experience.
A child or adult with progressive hearing loss, oral communicator: When it comes time for this candidate to get a cochlear implant, it’s just part of a natural progression when hearing aids are no longer enough. Though changing from acoustic (hearing aid) to electric (cochlear implant) sound may be a challenge at first, the CI then serves as a new tool to continue listening and spoken language progress.
A deaf infant: Receiving a cochlear implant and AVT early can open up the world for this child. The combination of early intervention and early auditory input means that this child has a shot at developing listening, speech, and language skills in a developmental, not remedial, manner, and can quickly catch up to hearing peers.
A deaf toddler/preschooler: This child is receiving a CI a little later than the as-soon-as-possible (12 months or earlier) that we like to see, but with appropriate listening and spoken language therapy and making more than month-to-month progress, we can expect him to catch up after some lag time, all other factors being in place.
An older child who is a manual communicator, doesn’t use hearing aids for communication (if worn at all): This child will most likely gain awareness of environmental sound with a CI and use the CI for assistance in understanding speech, but, depending on the child’s age and duration of deafness, a CI later in childhood for a child who is not an oral communicator is rarely enough to change their main mode of communication.
An older child who is an oral communicator and good hearing aid user: After an initial adjustment period as the child gets used to the new sounds she’s receiving with her cochlear implant, these patients often do quite well, as their brains developed in a listening and spoken language environment and what hearing they had was stimulated by the hearing aid. Even if these children have graduated from AVT, they can benefit from restarting therapy again for a brief period some focused listening practice.
These scenarios are certainly not exhaustive, and cover just a small range of the people who will be receiving a cochlear implant. Each patient’s case will vary and there are many factors (discussed above) that can influence the ultimate outcome. Here are some more resources:
AuSpLan: Auditory Speech and Language(Advanced Bionics — the first pages of this guide include information on expectations for pediatric CI candidates, dividing them into four categories based on their profiles)
Elizabeth A. Rosenzweig 