Auditory processing disorder
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ICD-9 | 388.4, 389.9, 389.12, or 389.14 |
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Auditory Processing Disorder (APD) (previously known as "Central Auditory Processing Disorder" (CAPD) is a disorder in how auditory information is processed in the brain. It is not a sensory hearing impairment; individuals with APD usually have normal peripheral hearing ability. APD is an umbrella term that describe a variety of problems with the brain that can interfere with processing auditory information.
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[edit] 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; "auditory cognition", the ability of the mind to match what is said with something logically related, reasonably expected or predictable to be said. The mind may either fail to be agile in matching an appropriately related meaning among other meanings or fail to retain and prepare for possible scenarios in the background thoughts given the continuously changing context of verbal communication."
[edit] Difficulties encountered in diagnosing APD
APD is recognized 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 other more severe forms of 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 recognized 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'.
[edit] 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
[edit] 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).[citation needed]
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.[citation needed]
Another explanation is that people with CAPD are both left and right brain dominant. In the average brain, it is the left hemisphere that interprets auditory information. In the brain of the individual with CAPD, the right hemisphere attempts to interpret at the same time as the left hemisphere causing each to step on one another. This tug of war causes a delay and confusion and the brain "zones out".[citation needed]
[edit] What it is like to have APD
Persons with this condition often:
- 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.
It appears to others as a problem with listening. Somebody with APD may be accused of "not listening".
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.
Another woman states:
I've been tested with an IQ of 148 and yet many people have referred to me as an airhead. This has caused me a great deal of anxiety and pain. I do fine in one on one conversations and am perceived as interesting, funny and smart but if you put me in the middle of a party or chaotic social setting, I appear confused and disorganized. I feel very embarrassed. As a kid, the school lunchroom was my worst nightmare and I would often sit next to a wall in my classrooms. The wall, I later learned absorbs excess sound which is why kids with CAPD tend to intuitively choose to sit next to it.
[edit] 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:
- Get directions and instructions in writing.
- 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.
- Many APDs use body language, lip reading and eye contact as a coping strategy.
- 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.
- Use closed captioning while watching television.
- Place with teachers whose speaking style is clear and organized, who are "good explainers," and who encourage questions, so that the person with APD does not have to decode complex verbiage. Rules of language activities, including writing, need to be made overt and very explicit.
[edit] 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)
- Fast ForWord (development of cognitive skills including auditory processing)
- PACE-Processing and Cognitive Enhancement
- Neuro-linguistic programming (NLP)...
- Brain Gym or Edu-Kinesthetics
- Physical activities which require frequent crossing of the midline (e.g. occupational therapy)
- Samonas Sound Therapy
- Auditory Integration Training (AIT)
- Sound Field Amplification
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. ASHA states: "However, well-designed, institutionally approved research protocals designed to assess the efficacy of AIT are encouraged. It is recommended that this position be re-examined should scientific, controlled studies supporting AIT's effectiveness and saftey become available."
[edit] External links
- ASHA APD Technical Report Jan 2005 (An Acrobat download of 20 pages of A4) This report is the result of some 5 years discussion to find a unified definition of APD for the USA, which was started by the first Bruton Conference in 2000.
- SchwabLearning.org: Auditory Processing Disorder in Children
- [Neuron Learning http://www.neuron-learning.co.uk/resources_CAPD.htm Providers of Fast ForWord in the UK & Ireland]
- UK Medical Research Council's APD pamphlet Oct 2004 The UK MRC published this pamphlet as a working document to define APD for the UK to herald their first 5-year APD research program, funded by the UK government. The links provides either a download of the pamphlet, or it can be read online.
- Auditory Processing Disorder in the UK (APDUK) web site includes online and downloadable copies of the UK Medical Research Council's APD pamphlet and much more information about APD (with input from Adult APDs) and related invisible disabilities.
- National Coalition on Auditory Processing Disorders (NCAPD) Relaunched website of a US non-profit organisation, containing a lot of information, including a directory of US Audiologists who can diagnose APD.
- Information Center on Disabilities and Gifted Education Overview on Auditory Processing Disorder.
- Central Auditory Processing Disorders as a key factor in Developmental Language Disorders A review of APD by SLT and audiologist, Rosalie Seymour.
- AudiologyOnline The Hearing Journal Auditory processing disorder: An overview for the clinician, by Gail D. Chermak.
- OldAPDs: Adult APD Forum A forum for Adult APDs to exchange experiences and provide mutual support. There is also an online research project participation.
- KidsHealth.org: Central Auditory Processing Disorder
- Autistics.org: Central Auditory Processing Disorder
- Two articles, written for Learning Disabilities Online by audiologist, Judith Paton:
- Auditory and Language Processing Disorders, by Kristen Jacobsen, MS CCC-SLP
- J. Baran & M. Schminky. 1999. University of Massachusetts, Communication Disorders Dept. Amherst, MA. University of Massachusetts - Overview of Assessment and Management Practices
- a-p-d group: professional discussion of Auditory Processing Disorders A listserv for Speech-Language Pathologists and Audiologists
- Auditory Processing Disorders in Children Article and links
- Math Professors Solve 'Cocktail Party' Problem Researchers have found a way to cull individual human voices from recordings of a noisy environment
- Auditory Processing Disorder therapy software for home or clinic use was created and tested by speech pathologists.