By Dr. JJ Whicker – September 20, 2021
I learned quickly in audiology school that central auditory processing disorder (CAPD) is a bit of a controversial topic among audiologists and other communicative disorder professionals. There are those who think CAPD is real but cannot be reliably assessed, those who think it can be assessed for but not treated, those who think both are possible, and those who think CAPD is just a ruse.
I am of the camp who believe CAPD can be assessed for and treated. It’s true, however, that there is not a gold, reference standard for practice when it comes to assessing and treating CAPD. What this means, is there is not a single test item, test battery, or intervention that has shown to be “the best” at reliably and repeatedly identifying and improving the impacts of this disorder. The result is that a lot of different assessments and approaches to treatment exist, and audiologists are at their leisure to use assessments and interventions they think are best based on their own clinical experience.
Despite this wide-open pattern of practice, there are key practice guidelines that are accepted as important components, at least in the identification of CAPD. The first is ruling out hearing loss. As a rule of logic, hearing loss is, itself, an auditory processing disorder; however, when talking of auditory processing disorders, usually people are talking about what the brain is doing with the sounds it can hear, not about how the structures of the hearing system are conducting sound to the brain. Hence, when referring to auditory processing disorders, I will include the term “central” to indicate that I am referencing the brain and its ability to make meaning of what gets to it, auditorily speaking. Ruling out hearing loss is important, because if hearing loss does exist, we would want to intervene that before assuming there is something different about how the brain is able to process sounds. Of course, once hearing loss is intervened by amplification technology (if that is the patient’s choice), taking the time to understand the central processing of auditory stimuli is just as appropriate, and further intervention may be necessary for the patient to optimize how they make use of what they hear.
When assessing for CAPD, the goal is to look at the whole auditory system, which is rather complex. We hear with the brain, not just the ears. Auditory processing, therefore, includes all sorts of elements, including the brain’s ability to tell whether sounds are coming at the same time or not, even by mere milliseconds; the brain’s ability to tell if a sound is perceived softer in one ear over the other; the brain’s ability to retain auditory information and recall it in the short- and long-term; the brain’s ability to detect and process target speech from non-target speech or other environmental noise; and the brain’s ability to discriminate the sounds it hears and synthesize it all together to make meaning. That is a lot of neurological effort, yet our brains develop these abilities very early on in life.
When there is a delay or deficit in any one of these auditory processing components, individuals may struggle socially, academically, emotionally, and even vocationally. CAPD is a silent “disorder” that is difficult for others to understand, especially when hearing loss is not involved. I, myself, have worked with many other providers, including audiologists, who have been very dismissive of CAPD assessments when the audiogram (the graph on which we plot hearing sensitivity) is “normal”. Yet, I have also worked with students who have consistently passed peripheral hearing exams who cannot follow multi-step instructions, who ask for repetition so much it infuriates the teachers and parents, whose eyes gloss over after only five minutes of listening, because the burdens of listening and understanding are so extreme, they simply stop listening, escaping into the parts of their perfect minds that don’t need to attend.
The model we follow here at Little Heroes for both testing and treating CAPD is called the Buffalo Model, which was created by Dr. Jack Katz, a leading expert in CAPD. This model focuses on understanding what the brain does with what it hears and can tap into each of those auditory processing functions explained earlier. From the test battery, we approach intervention with the idea to help the brain practice doing what the testing shows it might not be doing efficiently. For example, one of the most common deficits shown in CAPD testing at our clinic is decoding, or the ability for patients to discriminate and make meaning of speech sounds. So, we practice doing just that. We present speech sounds in isolation and then in the context of words and help our patients learn the difference between, say, /p/ and /b/. In this way, if one says, “Put the box back in the pile of packing material”, our patients hear and understand just that, instead of hearing “Put the pox pack in the pile of packing material” and feeling confused or needing to work harder at using context to making meaning of what they heard.
One of the key interventions we provide here has to do with modifying our patients’ listening environment through technology. For us, this means low-gain hearing aids coupled to a remote microphone. Low-gain hearing aids are simply hearing aids that are programmed to enhance speech in noise. Unlike hearing aids programmed to make soft sounds louder for children who are Deaf or hard-of-hearing, low-gain hearing aids only provide amplification for high-frequency speech sounds with stronger noise-reductions features enabled. The remote microphone allows for the hearing aids to also act as on-ear speakers, so that the voices of primary communicators (e.g., teachers) can be streamed straight to patients’ ears, rather than travelling through a communication environment, competing with noise, and diminishing in volume with distance. Low-gain hearing aids are not a fix-all, and it’s important to continue with listening therapy. Further, not all patients find benefit in low-gain hearing aids, and we offer a trial before families commit to the cost of such technology.
CAPD can be emotionally exhausting for both our patients and their parents, which is why we are so passionate about advocating for the need to diagnose and treat CAPD. I cannot say how many times parents end up with their children in my office in tears, explaining that they have been tested repeatedly by school personnel and even audiologists saying that their children are fine, when the parents know in their hearts that there is something different with how their child responds to sounds. Here at Little Heroes, we consider parents as partners in expertise. We take your concerns seriously and we will not let you leave clinic without a plan of action that makes sense to you. If you have questions, you can now schedule FREE virtual consultations with our specialists to determine if a CAPD evaluation and or intervention is right for your child.
For more information, please watch this informative TEDx talk about the hidden prison of CAPD by Dr. Angela Loucks Alexander.
Listening Therapy – What Is It and Who Needs It?
With Great Responsibility Comes Great Power
Managing Use of Hearing Technology in Children
There Is Help: Hopelessness is Unacceptable
Getting Straight Answers About Auditory Processing
The Locked Door
School Year Worries
Still Human, Just Different
The Night I Went Camping With A Bear
The Emotional Journey of Childhood Hearing Loss