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Hidden Disability: Auditory Processing Disorder

Hidden Disability: Auditory Processing Disorder

Published: 06/25/2013 by Bonnie Landau Weed

» Health and Wellness

When a child has a disorder nobody can name, it can be downright despairing. That was me, four years ago, when my son entered kindergarten after transitioning from special education preschool. He went from loving school to hating it, from the best behaved in class to the most out-of-order. All the professionals around him kept harping on medication for Attention Deficit Disorder (ADD), but my mother’s intuition said it was something else.

I started to research and found an article that compared ADD to Auditory Processing Disorder (APD). When I read the symptoms of APD, I knew why my son was having such a hard time in his typical classroom.

Defining APD
When our ear hears a sound, the sound is taken into the inner ear and delivered to the brain and the brain translates what is being heard. When a person is deaf, the part of the ear that delivers the sound to the brain does not function. When a person has APD, the part of the brain that translates what the ear delivers does not function properly.

People who have APD have normal hearing. The outer ear, middle ear and cochlea are all functioning properly. The problem arises when the electrical signal from the cochlea is not processed accurately by the brain.

Causes of APD
Unfortunately experts have not been able to come to a definite conclusion about what exactly causes APD. Professionals theorize that people are either born with APD (hereditary) or something happens to their hearing system to cause APD (acquired).

With hereditary APD the brain is actually hardwired incorrectly. It is common to have several people in the family with APD and parents often discover their own diagnosis when seeking help for their child. Hereditary APD does not always gain help from therapies. A person’s best strategy is to learn how to accommodate their challenges.

Acquired APD is usually the result of some trauma to the brain. The most common cause is excessive ear infections in early childhood which retard the development of the auditory system. It can also come from any form of head injury, high fever or something traumatic that would affect the brain. Acquired APD can respond very well to therapies that improve brain function, but it is a trial and error process to figure out which therapies will help.

With no history of APD on either side of our family, we know our son has acquired APD. He had a series of 11 ear infections as a toddler and also a couple bad bumps to his head from climbing accidents. When he was 8-years old we confirmed through a QEEG brain map that he had mild traumatic brain injury and this was likely the cause of his APD.

How APD affects a child’s learning
Noise factor in a classroom is often the biggest challenge to an APD child’s ability to understand. It is common for parents to choose homeschooling for that reason. But even in a quiet environment, there are specific learning tasks that may be difficult.

A child with APD has difficulty processing aural information. Because the listening process requires concentration, the child’s brain does not have the resources to store in short-term memory what has been said. A child may exhibit signs of fatigue, inattention or frustration when listening to a story or conversation. It is important to reduce how much information is given at once and to ask the child to repeat back instructions to make sure they have been understood.

Fifty-seven per cent of children with APD have difficulty learning to read. Research has shown that APD affects the ability to distinguish specific sounds, or phonemes, within speech. This causes speech to be perceived as “muddied” or “blending all together.”

These children will often rely on their visual strengths to help them learn to read. They will not break apart words but learn the word in its entirety, like memorizing a picture. Unfortunately sight-reading makes long-term reading difficult and does not provide a strategy for sounding out unknown words. It also causes difficulties with spelling and writing.

Guided Phonetic Reading (GPR) is a good solution. GPR uses characters to represent phonemes, and this provides a consistent presentation of the sounds, while at the same time helping the child to learn sound combinations. The child is able to rely on visual strengths to learn to read phonetically, and the knowledge provides a strategy for decoding unknown works.

How APD affects my child socially
The social challenges of APD are often the most difficult aspect of this disorder and often require change of environment to remediate.

Noisy playground environments and groups of children who often all talk at once cause frustration for a child with APD, leading to shyness or self-isolation. One–on-one social interactions are preferred.

Since the child is so focused on trying to process what is heard, subtle social cues are often missed. The child may not comprehend that somebody is upset when they cross their arms in a huff, for example. It is important to teach the child to use the visual strength to recognize social cues. Social skills classes are very effective to this end.

Lastly, because of the communication issues and social immaturity, it is not uncommon for a child with APD to struggle with acceptance from peers. Often this stems from a misunderstanding, from thinking the child with APD does not “play by the rules.” At times like these I have actually told children that my son has a hearing problem and he doesn’t always understand what is said. Children seem to understand this and sometimes will accommodate more readily by repeating what they have said.

How APD is diagnosed

APD is a difficult disorder to detect and diagnosis because it looks like other more common learning or behavioral issues. A person can also have multiple diagnosis (ADD and APD are often found together), but sometimes APD is not detected as it is overshadowed by the more familiar diagnosis.

The only person qualified to make a diagnosis for APD is a specially-trained audiologist.

Unfortunately there are no specific-measure tests, like an MRI or blood test, which can detect the presence of APD. In order to determine if a person has APD, a series of behavioral and hearing tests must be administered by an audiologist.

The following list of tests is based on a generalized standard used by audiologists in the USA and Canada, but no association, organization or governmental agency has established a standard series of tests for APD diagnosis.

• Hearing: The first tests will be basic hearing tests to rule out any hearing loss.

• Neurologic: The technical term is Electrophysiologic tests. Administering these tests involves the use of electrodes, which measure brain response to sound stimuli.

• Behavioral: This involves presenting spoken information with portions of the words purposely missing. A person without APD can fill in the gaps and understand what is said, while an individual with APD cannot.

• Dichotic: These involve presenting specific numbers or words alternatively in each ear, and the patient must repeat all that has been said in both ears.

It is common for professionals who specialize in diagnosing developmental issues to say they have assessed for APD even though they are not an audiologist. My son was assessed by at least a half dozen professionals who all said my son’s auditory processing skills were fine. When a properly-trained audiologist was finally consulted it turned out he had severe APD.

The general consensus among audiologists is that it is not possible to diagnose a child under the age of 7. The reasons cited are usually: lack of maturity in the neurology of the auditory system, lack of maturity in the child’s ability to sit still and cooperate with testing and norms for tests are usually for 7 years and older.

However, there is a subset of audiologists who believe children as young as 5 can be tested and diagnosed with APD. If a parent feels strongly about having tests done before age 7 they should seek out an audiologist who has experience in this age group.

Remediation
There are therapies available to remediate the symptoms of APD. Success varies from child to child. Some therapies are computer-assisted programs such as Earobics and Fast ForWord. Others are listening therapies such as Auditory Integration Training (AIT) and The Listening Program. Some therapies are one-on-one sessions with a therapist to improve cognitive function such as BrainGym or Musgatova Method. There are even therapies that can change brainwave activity and improve auditory function, such as neurofeedback. There is no one-size-fits-all treatment.

An individualized program should be developed based on the child’s specific auditory deficits and family history. Some children may see improvement of all symptoms and others may not improve much at all. Despite this, all children with APD should be taught how to request necessary accommodations and ask for clarification so they become self-advocates.

In our son’s case we have seen tremendous progress with the therapies we have tried, the best of which were AIT and neurofeedback. His ability to understand conversation in noise has been normalized. We expect to see continued improvements in memory and social skills as he grows.

You can listen to a simulation of APD at www.exploratorium.edu/exhibits/ladle/index.html where the narrator reads Little Red Riding Hood in the way a person with APD might hear it. The Canadian Association of Speech-Language Pathologists & Audiologists has a searchable database on their site, www.caslpa.ca, that allows parents to find APD audiologist specialists. 

Sharma et al., Comorbidity of Auditory Processing, Language, and Reading Disorders, Journal of Speech, Language, and Hearing Research Vol.52 706-722 June 2009

Musiek et al., Testing and treating (C)APD in head injury patients, Hearing Journal, June 2008 - Volume 61 - Issue 6 - p 36-38

Wright et al., Nonlinguistic perceptual deficits associated with reading and language disorders, Current Opinion in Neurobiology, Volume 10, Issue 4, 1 August 2000, Pages 482–486

Watson et al., Auditory Perception, Phonological Processing, and Reading Ability/Disability, Journal of Speech and Hearing Research Vol.36 850-863 August 1993