Auditory processing disorder

Auditory Processing Disorder (APD) (previously known as "Central Auditory Processing Disorder" (CAPD)) is not a hearing impairment (i.e., a person with APD usually has nothing wrong with his or her ears), but an inability to process what is heard. APD is an umbrella term that describe a variety of problems with the brain that can interfere with processing auditory information.

Definitions
The "American Speech + Language - Hearing Association" (ASHA) have recently published the first definitive (Central) Auditory Processing Disorders Technical Report, Jan 2005, which complements the UK's "Medical Research Council's Institute of Hearing Research's" Auditory Processing Disorder (APD) pamphlet, Oct 2004.

Both of these documents provide the first comprehensive definitions of APD in the respective countries, and a platform for future research and development of diagnostic systems and support programs. (There are links to both documents included in the External Links section below.) They cover the various causes of Auditory Processing Disorder including both the genetic causes and the acquired causes (such as severe ear infections and severe head injuries).

Aspects of auditory processing which may be affected by APD include "auditory discrimination", the ability to distinguish between similar sounds or words; "auditory figure-ground", the ability to distinguish relevant speech from background noise; and "auditory memory", the ability to recall what was heard.

Difficulties encountered in diagnosing APD
APD is recognised as a major cause of dyslexia. As APD is one of the more difficult information processing disorders to detect and diagnose, it may sometimes be misdiagnosed as ADD/ADHD, Aspergers and even autism, but it may also be a comorbid aspect of those conditions if it is considered a significant part of the overall diagnostic picture. APD shares common symptoms in areas of overlap such that professionals who were not aware of APD would diagnose the disabilities as those which they were aware of.

People with APD intermittently experience an inability to process verbal information. When people with APD have a processing failure, they do not process what is being said to them. They may be able to repeat the words back word for word, but the meaning of the message is lost. Simply repeating the instruction is of no use if a person with APD is not processing. Neither will increasing the volume help.

People with APD have an Auditory (Verbal) Processing Disorder, and text is only verbal code, and so the Auditory Processing Disorder is extended into reading and writing as this auditory code. As a consequence, APD has been recognised as one of the major causes of dyslexia.

There are also many other hidden implications, which are not always apparent even to the person with the disability. For example, because people with APD are used to guessing to fill in the processing gaps, they may not even be aware that they have misunderstood something.

In many instances, APD comes as part of an 'invisible disability' package, and in some instances, the other disability may mask the APD. This multiple disability scenario indicates that a transdiscipline approach to research, diagnosis and treatment is of the utmost importance, especially when APD can mimic many of the other 'invisible disabilities'.

Behavioral manifestations
Some of the manifestations below may be observed in individuals with other types of deficits or disorders, such as attention deficits, hearing loss, psychologically-based behavioral problems, and learning difficulties or dyslexia. Common behavioral characteristics often noted in individuals with APD include:


 * Difficulty understanding what people are saying when there's background noise, such as noise at a party or wind on an outdoor hike
 * Difficulty following long conversations
 * Difficulty hearing conversations on the telephone
 * Preferring to learn a foreign language (or challenging vocabulary words, or difficult last names) by learning to read and write the words first, and then learning to hear and speak the words, and then only when the words are spoken slowly
 * Difficulty remembering spoken information (i.e., auditory memory deficits)
 * Difficulty taking notes
 * Difficulty maintaining focus on an activity if other sounds are present; child is easily distracted by other sounds in the environment
 * Difficulty with organizational skills
 * Difficulty following multi-step directions
 * Difficulty in dividing attention
 * Difficulty with reading and/or spelling
 * Preferring to watch movies with the subtitles or closed-captioning on
 * Sensitivity to certain noises (e.g., inability to "tune out" a television on in the background while "tuning in" a conversation with a person).
 * Difficulty picking out one musical instrument from a band or orchestra

Causes of APD
While there is no one cause, the disorder will occur in various locations along the path, followed by acoustic signals as they are received, transition into neural signals and then ultimately pass through neural networks from the ear to the brain for additional analysis (before the ultimate recognition or comprehension and response).

In many people, the development of important auditory centers within the brain is linked directly to maturational delays which result in this disorder. In others, variations in brain development can lead to benign differences and create the deficits. For many, this is a genetic disorder which is inherited and runs in families. Sometimes, the disorder may relate to neurological problems caused by tumors, trauma, surgical mishaps, disease, viral infections, oxygen deficiency, lead poisoning, auditory deprivation, or anything along these lines.

What it is like to have APD
Persons with this condition often: It appears to others as a problem with listening. Somebody with APD may be accused of "not listening".
 * have trouble paying attention to and remembering information presented orally;
 * have problems carrying out multi-step directions given orally;
 * have poor listening skills; and
 * need more time to process information.

One adult, who has had the disorder since childhood, writes:


 * "My hearing is fine, but what I hear is often garbled initially by my brain. Shortly later, I often figure it out. In conversation, about the same time I say "huh?', I figure out what it was that I just heard. Like the three-legged dog, I am told that my visual skills, in compensation, are much stronger than normal. My bottom line is: I do better with what I see than what I hear."

Coping skills and work-arounds
Adults who discover disabilities such as APD late in life have provided some insight into coping skills they have found helpful. These include:


 * 1) Get directions and instructions in writing.
 * 2) Do not take notes yourself when information comes from others orally, as this may interfere with your processing strategies, but ask others to provide notes for you.
 * 3) Many APDs use body language, lip reading and eye contact as a coping strategy.
 * 4) Rewrite text using multi-coloured text options to provide visual guide to changes in meaning or for new sentences, or use a set of coloured highlighters.
 * 5) Use closed captioning while watching television.
 * 6) Place with teachers whose speaking style is clear and organized, who are "good explainers," and who encourage questions, so that the person with ADP does not have to decode complex verbiage. Rules of language activities, including writing, need to be made overt and very explicit.

Remediations and Training
No one program is a cure or help all for APD.

APD is about creating coping strategies to meet the challenges life presents and using the various strengths each of us may have.
 * Management of Auditory Processing Disorders (includes the use of many programs)
 * Lindamood-Bell Learning Processes (particularly, the Visualizing and Verbalizing program)
 * Neuro-linguistic programming (NLP)
 * Brain Gym or Edu-Kinesthetics
 * Physical activities which require frequent crossing of the midline (e.g. occupational therapy)
 * Auditory Integration Training (AIT)
 * Auditory Integration Training - ASHA Position Statement 2004 American Speech language Hearing Association ASHA Position Statement on Auditory Integration Training which includes references to the auditory integration therapies (AITs) Tomatis, Samonas Sound Therapy, and The Listening Program, and refers to correspondence with Advanced Brain regarding these products. To date, according to the ASHA 2004 statement, these treatments fall outside the range of safe, evidence based interventions.