AUDITORY PROCESSING DISORDER;(CENTRAL) AUDITORY PROCESSING DISORDER

BY: Madonna Kellen, Tammy Oleson, Jacob Udvig, Amanda Wenner, Julie Wenner

In 1993 the American Speech-Language-Hearing Association (ASHA) set out to develop a “statement of consensus” in which professionals could identify auditory processing problems.

A task force made up of experts in the field of audiology was developed to define and answer the four basic questions associated with auditory processing issues.

AUDITORY PROCESSING AS IT EVOLVES…

“Issue #1—What does basic science tell us about the nature of central auditory processing and its role in audition?

Issue #2—What constitutes an assessment of central auditory processing and its disorders?

Issue #3—What are the developmental and acquired communication problems associated with central auditory processing disorders?

Issue #4—What is the clinical utility of a diagnosis of central auditory processing disorders?”

They were asked to answer the following questions within their research…

THEY ARRIVED AT THE FOLLOWING CONSENSUS…

“Central Auditory Processes are the auditory system mechanisms and processes responsible for the following behavioral phenomena:

• Sound localization and lateralization• Auditory discrimination• Auditory pattern recognition• Temporal aspects of audition to include:

– temporal resolution– temporal masking– temporal integration– temporal ordering

• Auditory performance decrements with competing acoustic signals.

• Auditory performance decrements with degraded acoustic signals.”

THEIR DEFINITION…

“A Central Auditory Processing Disorder (CAPD) is an observed deficiency in one or more of the above-listed behaviors. For some persons, CAPD is presumed to result from the dysfunction of processes and mechanisms dedicated to audition; for others, CAPD may stem from some more general dysfunction, such as an attention deficit or neural timing deficit, that affects performance across modalities. It is also possible for CAPD to reflect co-existing dysfunctions of both sorts.”

FROM THIS CONSENSUS GREW DEBATE OVER…• Definition

– Information processing theory• Diagnosis

– Is not always recommendation driven.• Assessment

– May perform poorly on an APD assessment battery yet have no evidence of speech or language problems or visa versa.

• Treatment – Does not correlate and are not driven by assessment.

• Coexistence /confusion with other disabilities– Sorting out auditory processing disorders and receptive

language disorders.

IN 2005 THE DEFINITION CHANGES…

“Broadly stated, (Central) Auditory Processing [(C)AP] refers to the efficiency and effectiveness by which the central nervous system (CNS) utilizes auditory information.”

“Narrowly defined, (C)AP refers to the perceptual processing of auditory information in the CNS and the neurobiologic activity that underlies that processing and gives rise to electrophysiologic auditory potentials.”

LIMITATIONS TO DEFINITION…“Although abilities such as phonological awareness, attention to and memory for auditory information, auditory synthesis, comprehension and interpretation of auditory presented information, and similar skills may be reliant on or associated with intact central auditory function, they are considered higher order cognitive-communicative and/or language-related functions and, thus, are not included in the definition of (C)AP.”

INCIDENCE…

May effect as many as 10% of children. Effects more boys than girls . More common than hearing loss.

GRAVEL, WALLACE, AND RUBEN RESEARCH STUDY (1996)…

Children with mild, fluctuating hearing loss associated with otitis media had long term problems with higher an auditory-processing skills and learning.

Many more children have auditory learning impairment from CAPD than from hearing loss.

CAPD is more “hidden” deficit because hearing impairment is usually recognized more easily and associated more directly with marked effect on speech and language.

HIGH OCCURRENCE WITH OTHER DISORDERS…

ADHD Dyslexia Maturation delays Problems in central nervous system Autism

CAUSE OF DISORDER…

There is no known cause for this disorder. The amount of variables that need to be

considered is especially large, when taking in all that goes into taking in information as well as processing it. 

Inherited genetics Severe ear infections, Otitis Media, with effusion Head trauma Part of the aging process Damage to the Auditory nerve, which results in

auditory neuropathy . And many unknown reasons .

SYMPTOMS OF CAPD…

Trouble paying attention Trouble with multi-step directions Poor listening skills Extra time needed to process information Low academic performance Behavior problems Difficulty with reading, comprehension,

spelling and vocabulary

PHONOLOGICAL AWARENESS

Defined:“An awareness of how speech sounds are used in words.”

AFFECTED AREAS OF PHONOLOGICAL AWARENESS…

Manipulation –Ability to delete or alter the letters in a word and determine what the new word would be (cat = bat = tab).

Segmentation – Separate out speech sounds in a word (C-a-t).

Sound Blending – Ability to take separate speech sounds and put them together into a meaningful utterance (b-l-a-ck).

MANY CHILDREN AND ADULTS WITH CAPD HAVE PROBLEMS WITH PHONOLOGICAL AWARENESS HOWEVER PHONOLOGICAL AWARENESS ALSO REQUIRES…• Memory skills• Ability to follow complex directions.• Good representation of speech sounds.• Segmentation of speech .• Modularity (clapping and singing)• Sound blending (knowing which sound correlates

with which letter of the alphabet).These tasks cross a wide range of skills and therefore it is important to consider the suspicion of a more global, higher level cognitive disorder.

SYNTAX…

With difficulty in syntax, the way in which words in a sentence are put together, they may struggle with connecting words to their meanings. 

PRAGMATICS…

The social issues that people with CAPD face are numerous. Due to the fact that their hearing is ok and their IQ is ok, they are often perceived as people who…

1. Are not following directions… but in reality are not understanding what is said.

2. Do not listen good enough… but in reality are listening, and can’t process what is said.

3. Are shy… but are afraid to step out, in case they understood wrong.

4. Are poor students… but truly want to do their best.5. Are rude… but truly did not know they needed to

respond.

PRAGMATICS CONT…

6. Are unorganized… but truly did not understand where to put things.

7. Are slow… but truly need more time to think through what people are saying.

8. Are poor note takers…. But truly did not process the information needed.

9. Do not meet deadlines….. but truly did not process the correct time frame.

10. Have behavior problems… but have learned this in result of not being understood, or understanding.

MORPHOLOGY…

Since a morpheme is the smallest unit of sound that holds meaning, a person with CAPD struggles with processing the sounds that he or she hears correctly.

Often words or sounds that are close are mistaken for each other.

One example is coat for boat,   Another example: ch for sh.

SEMANTICS…

People who have CAPD also have difficulty attaining the correct meaning for what is being said to them. Due to this difficulty they often have troubles with reading, writing and doing math computations.

ASSESSMENT… The first test that needs to be done is a routine hearing

test to make sure that you can hear and are not just deaf.

Then there are many different tests that will be used in the assessment of CAPD to determine the various auditory functions of each persons brain.

There are two main categories of test: electrophysiologic test and behavioral test which are then broken into four subcategories: monaural low-redundancy speech test, dichotic speech test, temporal patterning test, and binaural interaction test.

Not all children will be administered all these tests. Which test the child will take depends on a number of

factors including, the age of the child, the specific auditory difficulties the child is displaying, the child's native language and cognitive status.

ELECTROPHYSIOLOGIC TESTS…

These test measure how the brain response to sound.

How these tests are preformed is by placing electrodes on the earlobes and head of the child being tested. These will measure the electrical potentials that will arise from the central nervous system as a response to the auditory stimulus.

Then an auditory stimulus, such as a clicking sound is distributed to the ear of the child and the electrical responses are then recorded.

These test can be used to evaluate the processing of the lower brain, which involves the auditory brainstem response audiometry.

BEHAVIORAL TEST…

This test is designed to test how well a person can achieve auditory closure when there is pieces of information missing.

The speech stimuli that is used in the test will be modified by changing either the characteristics of the speech signal, frequency, temporal, or intensity characteristics.

Compressed Speech test (Beasley Schwimmer, and Rintelmann, 1972) is an example of this kind of test.

In this test parts of the speech signals have been altered electronically by removing portions of the original speech. Then these items are presented to each ear separately and the individual has to repeat the words that have been presented.

Monaural Low-Redundancy Speech Test

BEHAVIORAL TEST…

These tests present the individual with different speech items either simultaneously or in an overlapping manner. Then the individual is asked to repeat either everything they heard, which is an example of divided attention, or they are asked to only repeat what they have heard in one ear, which show directed attention.

Dichotic Digits test (Musiek, 1983) is a commonly used test in this category.

In this test four numbers are conveyed to the individual’s two ears, two numbers in one ear at the same time and two in the other ear also at the same time. Then the individual is asked to repeat all the numbers they heard.

Dichotic Speech Test

5,9 1,6

BEHAVIORAL TESTS…

These tests are created to test an individual’s capability on processing nonverbal auditory signals, as well as being able to recognize the order or pattern that the presented stimuli represent.

The individual will either be asked to “hum” the patterns they hear or to explain the patterns in words.

If the individual hums the pattern then the processing of the information mostly happens will in the right half of the brain. When the individual describes the pattern in words then the left half of the brain will be used.

Frequency Pattern Sequences test (Musiek and Pinherio, 1987) is a very commonly used test in this category.

This test consists of three short tone bursts in one or both ears. In this pattern two of the bursts are of the same frequency and the third is a different frequency. The only tones used are high and low frequency sounds which the child is then asked to describe.

Temporal Patterning Test

BEHAVIORAL TEST…

This test will test children’s ability of the structures low in the brain, such as the brainstem, and how good this part of the brain is at taking incomplete information that is presented to both ears and combining the information together in some form.

The Rapidly Alternating Speech Perception test (Willeford, 1976) is another common test used in this category.

In this test a sentence is divided into brief segments which are then alternated between both ears. For example in the word “put” the “pu” would be presented in one ear and the rest of word in the other ear, and the child would have to put the word together.

Binaural Interaction Test

TREATMENT… There is still much research needed in order to find the

best intervention possible for an individual with CAPD, but there are some strategies that are available.

Any strategy that is used should be used under the guidance of professionals with the effectiveness of the strategy on the individual monitored and evaluated.

Once again which the strategy that will work the best all depends on many different factors like, the exact nature of the CADP, the age of the individual, any co-existence of other disabilities, and the availability of resources.

The strategies fall under three main categories which are;

1. Enhancing the individual’s auditory perceptual skill.

2. Enhancing the individual’s language and cognitive resources.

3. Improving the quality of the auditory signal (cite).

STRATEGIES…

There are five main strategies for improving CADP;1. Auditory Trainers, which are electronic devices that

allow a person an easier time to focus on the speaker and block out any background noise. These are used a lot in a classroom setting when the teacher wears a microphone and transmits the sound the a child wearing a headset of hearing aids.

2. Environmental Modifications, which is as simple as classroom acoustics, and or placement of the child in the classroom. An audiologist may be able to offer some advise on ways to improve environment listening.

3. Language-Building Skills, which are different exercises that can increase an individual’s ability to learn new words and also increase their language base.

STRATEGIES CONT…

4. Auditory Memory Enhancement, which is a strategy that can be used by teacher and or therapists by making detailed information more simpler and basic to comprehend.

5. Auditory Integration Training, is a way to retrain the auditory system in individuals also decrease hearing distortion. Although there has been no proven benefits of this form of treatment yet.

6. The most important thing and the most stressed strategy that will make the most improvements is to make each program based on the individual's needs.

TIPS FOR PARENTS…

Try to reduce any background noise when trying to communicate with your child.

Make sure your child is looking at you when you speak.

When talking to your child use very simple and expressive sentences.

Speak at a little slower rate and raise your volume a little to make sure they are getting everything.

Have your child repeat back to you instructions out loud.

Write your child reminder notes, and also having your child wear a watch will help.

Keep a general organization of the house and the same basic routine and chores.

Create a quite place for your child to study. Help your child build their self-esteem.

TIPS FOR TEACHERS…

Make sure you speak very clear when giving directions to the class.

Rephrasing the information again in a different way can help reinforce it and it helps to hear the information again.

Create a seating chart with the child in a quite place and where they can most easily hear you teach.

Reinforce your information with visual aids to help out when the auditory information is lost.

THINGS PARENTS AND TEACHERS CAN DO TO HELP STUDENTS WITH CAPD…

Reduce or eliminate background noise in classrooms, or at home.

Insure that the classrooms the student is in are acoustically sound.

Provide opportunities for the student to pre-learn new vocabulary being taught.

Give child visual and audio instruction. Teach the child strategies that will foster

focusing on the speaker. Use simple, straight forward sentences in

your speaking.

THINGS PARENTS AND TEACHERS CAN DO TO HELP STUDENTS WITH CAPD CONT…

Use a little bit slower rate when speaking. Use a little lower volume when speaking. Use rephrasing instead of repeating when a

child misunderstands. Have the child repeat directions to insure their

understanding. When directions are to be taken at a later time,

insure the child has taken correct notes, so that the instruction can be followed through.

Teach strategies for self advocacy that include the child positions self in the quietest spot for learning.

THINGS PARENTS AND TEACHERS CAN DO TO HELP STUDENTS WITH CAPD CONT…

Provide a quiet study area for child at home and school.

Ask to sit in front of classroom, or within 10 feet of the speaker.

Keep classroom and home as chaotic free as possible.

Encourage healthy eating habits. Provide structure. Teach organization strategies. Foster positive self-esteem. Remember that CAPD is REAL!

PERSONAL ONLINE INTERVIEW OF:TERI JAMES BELLIS, PH.D., CCC-A, FAAA, F-ASHA PROFESSOR AND CHAIR, DEPARTMENT OF COMMUNICATION DISORDERS DIRECTOR, SPEECH-LANGUAGE-HEARING CLINICS

What historical changes have you seen to the definition of auditory

processing disorder? “Mostly it has been honed to make it clear that this is aNeurobiological disorder involving the central auditory

pathways,Not just "listening." It's a diagnosis, not a descriptor.”

What is your general definition of auditory processing disorder?

“I use the ASHA (2005) definition.”

INTERVIEW QUESTIONS CONTINUED…What problems in phonology would a child with an auditory

processing disorder present with? “I would say that children with CAPD often present withphonological difficulties that involve substitutions of

similarsounding phonemes (e.g., stop consonants and others

thatinclude rapid spectrotemporal acoustic changes) and/ordeletions of weak phonemes.”

What motivated you to begin working in the area of CAPD?“Had an interest in neuroscience from way back, and

coupledwith my interest in pediatrics...well, that's where the

two met somehow. Really just fell into it!”

FOR MORE INFORMATION ON CAPD AND INTERVENTIONS TO USE SEE THE FOLLOWING WEBSITES: http://www.themlrc.org/index.htm www.tomatis.com www.earobics.com http://www.asha.org http://www.audiology.org http://www.edaud.org http://www.theshop.net/campbell/central.htm http://www.audiologyinfo.com http://www.searchwave.com http://www.kidspeech.com/tips.html http://www.engr.colostate.edu/depts/eeresearch/cad http://www.kidshealth.org/parent/healthy.centralauditory.html http://www.listen-up.orghttp:pages.cthome.net/bristol/capd.html http://www.hearingbalance.com/hbscapd.htm http://www.families.com/experts/advice/0.1183.1-3347.00.html http://www.thehearinjournal.com

REFERENCES American Speech-Language-Hearing Association. (1996). Central Auditory

Processing: Current Status of Research and Implications for Clinical Practice [Technical Report]. Available from www.asha.org/policy.

Auditory Processing Disorder (APD). MRC Institute of Hearing Research. April2004. British Society of Audiology APD Special Interest Group. Aug 9 2008.

Baran, Jane. An Overview of Assessment and Management Practices. “Central Auditory Processing Disorders.” April 27 2004. Department of Communication Disorders. Aug 6 2008.

Bellis, T. J. (2004, March 30). Redefining auditory processing disorder: An audiologist‘s perspective. The ASHA Leader, pp. 6, 22-23.

Bellis, Teri. Why the brain can't hear: Unraveling the mystery of Auditory processing disorder. New York: PB Press, 2002

“Management of Auditory Processing Disorders.” Kidspeech. 2008. 08/08/2008. Morlet Thierry PhD. “Auditory Processing Disorders.” KidsHealth. 2007. 08/08/2008. NIDCD. Auditory Processing Disorder in Children. “National Institute on Deafness and

Other Communication Disorders.” Feb 2004. NIDCD. Aug 6 2008.http://www.nidcd.nih.gov/health/voice/auditory.htm#5.

Paton, Judith. “Living and Working With a Central Auditory Processing Disorder (CAPD).” LDOnline. 2008. 8/08/2008.

Pillow L. Gary. “Auditory Processing Disorders A Guide for Parents andProfessionals.”08/08/2008.

Richard, G. (2004, March 30). Redefining auditory processing disorder: A speech-language pathologist‘s perspective. The ASHA Leader, pp. 7, 21.

Young L. Maxine M.S., CCC-A/SLP, FAAA. “Recognizing and Treating Children with Central Auditory Processing Disorders.”http://www.scilearn.com/results/foundationalresearch/whitepapers/index.php#capd.

08/08/2008.