Defining APD and Predicting Benefit from Interventions
My answers to two questions (subject to change as we all learn more):
1. Is APD a learning disability?
2. Can you predict if someone will succeed with a particular intervention?
My definition of Auditory Processing Disorders is that it is not a single disorder, it should really be called Auditory Processing Disorders (plural) . APD symptoms can arise from a wide combination of factors, ranging from heredity to alcohol use in utero to head injury to auditory deprivation or illness.
I think that the belief that APD is a “pure” disorder, only existing in isolation from other comorbidities, such as autism, ADHD, dyslexia, etc., is unfounded. Yes, you can have the symptoms of APD, and even a full diagnosis of the disorder, without having co-occurring difficulties. However, the majority of patients I work with, simply do not fit that model.
APD, like many other similar diagnoses, is primarily identified through a series of performance-based tests and case history. Diagnosis of APD is typically fully unrelated with the actual cause of the disorder. Much like looking at the surface of a river and watching the current swirl and bubble, while unaware of what rocks or other hazards may lay beneath causing turbulence, in many cases, the cause of APD symptoms is simply a mystery.
As a medical professional, I do believe that the underlying cause of a disorder has some relevance when considering certain cases. Particularly in cases of fluctuating hearing loss and auditory deprivation due to middle ear infections in young children, I think we need to reconsider our “wait and see” approach, as the child falls further and further behind and, instead take action. I think it’s also important to know if more than one child in the same family is having similar difficulties, so as to possibly intervene before problems develop.
APD does not only affect the young. Even in the absence of hearing loss, many adults start having considerable difficulties hearing in noisy environments starting as early as in their 40s. This difficulty can lead to isolation and depression as they avoid interacting in noisy environments.
Older adults and seniors, also may suffer considerably when unidentified as having (even a mild level) of hearing loss. As with younger adults, a slight hearing loss or difficulty hearing in noise can lead to an increased chance of isolation, depression, reduced working memory, dementia, and dangerous falls. It is crucial that the adult and geriatric populations are aware of the negative impact of ignoring symptoms associated with APD as well as measured audiometric hearing loss. It is well established that left untreated, hearing loss may result in auditory deprivation, a state which has been linked to further distortion of hearing discrimination, as well as other symptoms of APD.
It is not yet fully clear which interventions may or may not work for specific groups of children or adults, whether it is based upon their grouping by symptoms of APD, according to one evaluation or another, or whether it is based upon their initial cause of APD. There are, of course, certain auditory training software programs espoused by audiologists, programs designed for very specific purposes, such as practicing the use of both ears at the same time, improving auditory memory for the purpose of listening in noise, or listening to slowed down speech so as to improve temporal resolution when it is then sped up. Many clinicians swear by auditory training, and cite articles that show changes in brain function based on auditory waveforms. As to whether those changes are long-standing, I can’t speak to that, because the majority of the studies do not go beyond a few months post training. However, many children and adults clearly obtain some benefit that then carries over into other lasting skills.
I see APDs as being a lot like a hearing loss in that its symptoms results in similar fallout. That is, APD tends to primarily impact access to speech reception, comprehension, auditory memory, spoken language, literacy, and pragmatics.
I believe that in an mainstream educational or work environment, without adequate or appropriate accommodations or interventions, in most cases, APD should be considered a central hearing loss, for the simple fact that it often impedes the ability for an individual to learn and function at a level commiserate with their ability with those supports in place.
Even when learning occurs, and everything seems fine at the surface, APD-related turmoil may nonetheless occur. Many children and adults have considerably more difficulty with remembering the information from lessons due to their overtaxed systems. Severe fatigue is common after a long day of listening or writing. Headaches and migraines occur as a result of exposure to loud sounds or excessive strain to listen. Social skills are often delayed or impaired as the child or adult is unable to juggle the communication needs of a typical school or work environment with learning social interplay.
In the case of a student or employee being in a situation where accommodations are available or the universal design is such that they are not struggling, I think it could still be argued that APD functions as an impediment to function, in essence still a learning disability, as their success is partly contingent upon their environment.
Interventions are few and far between, with the exception of standalone FM. The use of an FM system (eg, Phonak Roger Focus) may amplify the teacher but it certainly does not help with the socialization or noise protection often required by individuals with APD. Isolating a child from everyone in the class, except for the teacher to whom they are bound, FM systems allow little to no control of input, and maintain the individual in a virtual bubble of sound.
FM use does have a history of improving literacy in children with dyslexia, in part because they receive a better access to sound, and perhaps also because they can’t not listen to the voices piped into their ears. There are a plethora of articles that show children from various backgrounds, from attention deficit to APD, to those incarcerated in the juvenile system, improve both in language as well as in behavior as a result of this obligatory intervention.
Building upon the successes of FM use, in 2013, I decided to try low gain programmed hearing aids with a pre-teen , for whom diagnosis was murky, to say the least. Had I been planning to enroll children in a study of APD and benefit from low gain programmed aids, I would have had to turn her away.
There is no way I could have predicted with any certainty whether my first low-gain recipient, would have benefited. (As an aside I would like to say that I had already been working in the field for more than a dozen years. She was just my first patient of this type).
Prediction of benefit from low-gain programmed aids remains the same today. There is no way to be certain who will benefit and who won’t benefit from low gain programmed hearing aids. Following trials, well over half of our patients decide to go onto a permanent set of aids. If you’re wondering, in my experience, teenage boys in denial of APD difficulties are the least likely to do well, due to lack of cooperation and use.
With effective accommodations and interventions in place, most children and adults with APD can function well in academic and work environments. However, to be granted those accommodations, in our (US, UK, AUS, and NZ) societies, requires that you first clearly demonstrate a significant need via diagnosis of APD.
I may not believe that there is only one definition of APD (hence my tendencies to refer to APD in the plural), and I may not believe that APD is likely to be found in a pure form. Clearly, there are standards that need to be kept so that this diagnosis is not used indiscriminately. As of today, there is no international definition of Auditory Processing Disorders, or of the diagnostic evaluations that can be used to identify them.
As a professional, I need to remain informed, open-minded, and flexible enough to identify the subtle lines, below which signs of APD are evident. Diagnosing APD is not enough. I also need to stay up-to-date in my knowledge of the accommodation and treatment options, as well as if they are necessary, appropriate, and desired by or for that individual .
