Auditory Processing Disorder
Assessment, Diagnosis, Treatment and
Controversies
Defining Auditory Processing and APD
• Auditory processing may be described as the
“efficiency and effectiveness by which the central
nervous system (CNS) utilizes auditory
information.” (ASHA 2005)
• ASHA defines Auditory Processing Disorder as
“a deficit in neural processing of auditory stimuli
that is not due to higher order language,
cognitive, or related factors” (2005).
• Bellis adds that the disorder occurs in the
absence of any documented “neuropathological
condition” (2002).
Visual Processing
Image received
Image perceived
General Characteristics and Symptoms
• Auditory Processing Disorder can
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occur with or without hearing loss
may run in families
affect a person’s ability to interact socially
affect children and adults with normal intelligence
• Symptoms Exhibited by Preschool Children
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Demonstrate delayed speech and language abilities or articulation errors (Ex.
Substituting d for g)
Have problems following directions at school or at home (Ex. “Find a book you want
Mommy to read to you.”)
Ask for repetitions frequently such as “What?” or “Huh?”
Are more comfortable following daily routines once they have been practiced or learned
rather than following verbal directions
Perform better with visual cues or models
(Bellis 2002)
Symptoms of APD
• Symptoms Exhibited by Elementary School Children:
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Behave as if a hearing loss is present despite normal hearing
Exhibit articulation errors that are developmentally inappropriate
Poor social skills (making and keeping friends)
Express extreme frustration and often say, “I can’t do this!” or “I don’t understand”
Poor reading or spelling skills
Uses memorized phrases and sentences
• Symptoms Exhibited by Adults:
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Inappropriate responses to “wh” questions
Poor expressive or receptive language
Difficulty with reading comprehension, spelling and vocabulary
Difficulty following long conversations
Difficulty following verbal directions especially when involving multi-step directions
(Bellis 2002)
Referral
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Audiologist should be contacted for a comprehensive hearing
evaluation if some type of hearing or listening problem is suspected.
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A referral by physician is not necessary for an Audiologist to assess
hearing but it may be required by some insurance companies for
reimbursement purposes.
(DeBonis 2008)
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Obtaining supplemental services at school:
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First someone raises a concern (parent, teacher, school psychologist) about the
child’s academic or communicative performance
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Based on the severity of the concern :
• (1) the child may be referred for special education assessment (can’t occur
without the parent’s permission)
• (2) the teacher may implement some classroom and related modifications
(which do not require special education classification)
• (3) continue to keep a close watch on the child’s performance and reconvene
at a later time to reconsider the need for special education referral
(Bellis 2002)
Prevalence
• There are “no authorized estimates of the prevalence” of
APD.
(ASHA 2005)
• Chermak and Musiek (1997) estimated that APD occurs in 2
to 3% of children, with a 2-to-1 ratio between boys and girls.
• 67% of ASHA certified SLPs who work in a school setting
report regularly serving children with APD
(ASHA 2005))
Areas of Deficiency
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Auditory Processing Disorder is defined as having a deficiency
in one or more of the following behaviors:
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Sound Localization and Lateralization
• refers to the ability to know where a sound has occurred in space
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Auditory Discrimination
• refers to the ability to distinguish one sound from another
• most often used for distinguishing speech sounds, such as phoneme /p/
from phoneme /t/ as in “hop” and “hot”
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Sound/Symbol Association
• the ability to associate a symbol (a letter) with a sound (S with “ssss”).
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Temporal Auditory Processing
• the ability to integrate a sequence of sounds into words
• the ability to perceive sounds as separate when they quickly follow one
another
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Auditory Figure Ground
• refers to the ability to perceive the main message when other sounds
are present (understanding a conversation in a movie theater)
(ASHA 2005)
Areas of Deficiency Cont.
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Tolerance-Fading Memory
• refers to weak short –term memory when information is presented
audibly in the presence of distractible sounds
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Sound Blending
• ability to blend individual speech sounds together into a meaningful
word (c-a-t cat)
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Auditory Closure
• ability to perceive information in which some of the information is
missing (“it is raining and I ____ my umbrella”)
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Decoding
• problems are related to difficulties with phonics
• may spell words phonetically, spell inconsistently, have reading
problems, confuse similar sounding words
(ASHA 2005)
Diagnosis of APD
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Diagnosis is also very difficult due to the fact that no two
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APD can be formally diagnosed only by an Audiologist.
individuals will exhibit the same symptoms or behaviors.
(ASHA 2005)
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Initially, an Audiologist should rule out hearing loss as a primary
cause of the symptoms exhibited.
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Factors that may help to determine if an APD assessment is
necessary:
– A child must be at least seven years old before a behavioral central
auditory evaluation can be completed.
– Hearing loss
– Significant cognitive or language delays related to mental
retardation, AD/HD, and/or Autism
(Bellis 2002)
Diagnosis
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The following factors influence behavioral testing performance and should be
considered when choosing the assessment battery:
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Chronological and developmental age
Cognitive abilities (attention, memory, education)
Linguistic, cultural, and social background
Medications
Motivation
Decision processes
Motor skills
(DeBonis 2008)
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The Audiologist will take a complete history and a variety of auditory processes will
be assessed such as:
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dichotic listening (listening to a different signal in each ear simultaneously)
perception of distorted speech (which may consist of filtered speech or very
rapid time-compressed speech)
perception of nonverbal auditory stimuli (tone patterns)
temporal auditory processing (sequencing and patterns, gap detection)
(ASHA 2005)
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APD screening can be conducted by audiologists, SLPs, and psychologists, using
a variety of measures that evaluate auditory-related skills.
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Other tests that are not administered in a sound booth should not be considered
diagnostic tests for APD, however, they may be used to provide valuable
information about the individuals overall listening and comprehension abilities.
(Bellis 2002)
Assessment Tools
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A complete battery of testing may include the following:
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IQ tests – WPPSI (preschool), WISC (6-16), WAIS (16+)
Academic tests – Woodcock Johnson
Auditory Processing tests – SCAN-C & SCAN-A
Auditory Skills Assessment (ASA)
Test of Auditory Processing Skills (TAPS)
Parent & teacher questionnaires – Behavioral
Assessment Scale for Children (BASC)
Conner’s Comprehensive Behavior Rating Scales
Assessment Tools
• Auditory Skills Assessement (ASA)
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Screen children as young as 3.6 years old
– Measures auditory and phonological processing skills
– Speech discrimination in noise
– Sound blending
– Rhyming
– Sound discrimination
– Sound patterning
Used as a preliminary assessment of skills as well as for a re-evaluation tool to measure
the success of interventions
• Test of Auditory Processing Skills (TAPS)
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Measures of various aspects of auditory processing as well as language processing
Phonological processing (decoding and encoding)
Auditory closure
Short-term auditory memory for contextual and noncontextual information
Language comprehension and making inferences
Types of APD
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There is no one universally accepted theoretical model of APD!
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The Buffalo Model – Dr. Jack Katz
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Looks at the relationship between patterns of performance on specific tests of auditory
processing and learning difficulties in children.
– Decoding
– Tolerance-Fading Memory
– Integration
– Organization
(Masters, Stecker & Katz, 1998)
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Dartmouth Medical School – Dr. Frankl Musiek
Divided auditory processing deficits into subgroups on the basis of underlying
brain-based etiologies.
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Bellis/Ferre Model
The model is based on both the underlying neurophysiology and the relationship
among different types of APD and language, learning and communication
difficulties.
(Bellis 2002)
Bellis/Ferre Model
• Three primary subtypes:
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Auditory decoding deficit
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Integration deficit
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Difficulty with speech in noise, speech discrimination, sound blending, retention of phonemes,
reading, speech to print may be poor.
Difficulty with multimodality tasks that require inter-hemispheric transfer of information.
Prosodic deficit
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Difficulty with humor, multiple meanings and utilizing information in suprasegmentals of speech.
• Two secondary subtypes:
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Associative deficit
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May demonstrate receptive language difficulties, can not apply rules of language to incoming
auditory information
Output-Organization
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Difficulty in sequencing, planning and organizing responses.
(Bellis 2002)
Management: Environmental Modifications
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Management of APD should incorporate three primary principles and all are
necessary for interventions to be effective:
– Environmental modifications
– Remediation techniques (direct therapy)
– Compensatory strategies
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Environmental Modifications:
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Classroom Accommodations
• Preferential Seating
• Pre-teaching of new material
• Frequently check for understanding
• Rephrase vs Repeat
• Provide a note taker
• Use visual cues and modeling procedures
• Amplification
• Personal FM systems
• Access to word processors and other technology
(Bellis 2002)
Management: Direct Therapy
• Phonological Awareness Activities:
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Discriminating between speech sounds that are similar (pop/top)
Discriminating between vowels (a in cat vs. e in egg)
Segmenting words (CAT=C…A…T)
Blending sounds into words (C…A…T=CAT)
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Before Therapy: Twhnkke, tvinjle kitsle rtaq. Hov I wnnddr wgat wou zre.
After Therapy: Twinkle, twinkle little star. How I wonder what you are.
• Auditory Closure Activities:
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Using contextual cues to fill in the missing pieces (Jack and Jill went up the ___)
Noise is added to make activities more challenging.
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Before Therapy: O ing ol was a ry o ol
After Therapy: Old King Cole was a merry old soul
• Selective Attention and Localization Activities:
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Training in dichotic listening
(Bellis 2002)
Management: Direct Therapy
• Temporal Patterning Training:
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Typically nonverbal exercises that address rhythm (clapping, tapping on the table)
• Prosody Training:
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Exercises to teach interpretation of nonlinguistic cues (tone of voice)
• Computer-Based Therapy Programs:
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Fast Forward
Earobics
Auditory Integration Therapy
(Bellis 2002)
Management: Compensatory Strategies
• It is important to become an ACTIVE LISTENER!
• The Whole Body Listening Approach
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Sit or stand up straight so that the body is alert
Lean the upper body slightly or the head toward the speaker
Keep your eyes on the speaker
Eliminate unnecessary movement
• Metacognitive and Metalinguistic Strategies
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Self-instruction
Self-regulation
Using context clues
Drawing inferences
Rephrasing information
Areas of Concern
• Many clinicians are still skeptical about the existence of APD
and point out three big areas of concern.
(1) Disorders such as Autism Spectrum Disorders, Attention Deficit Hyperactivity
Disorder (ADHD), language impairments and learning disabilities produce similar
behaviors associated with APD.
• Skeptical clinicians have deemed the auditory deficits a function of these broader
disorders.
(2) It is often difficult to diagnosis a problem if the problem can’t be seen.
• No two individuals will exhibit the same symptoms or behaviors
• no audiological assessments or medical physiologic tests that adequately differentiate APD
from other disorders
• Physiologic tests such as brain scans, electrophysiology and magnetic resonance imaging
(MRI) often fail to reveal any obvious structural or functional damage
(3) Finally, an individual’s motivation to participate in APD screening may lead to
problems making an accurate diagnosis.
References
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American Speech-Language-Hearing Association (1996). Central auditory processing: Current status of
research and implications for clinical practice. American Journal of Audiology, 5 (2), 41-54.
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American Speech-Language Hearing Association (2005). (Central) Auditory Processing Disorders
[Technical Report]. Retrieved from www.asha.org/policy.
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American Speech-Language-Hearing Association. (2005). (Central) Auditory Processing Disorders—The
Role of the Audiologist [Position Statement]. Retrieved from www.asha.org/policy.
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Bellis, T. (2002). When The Brain Can’t Hear: Unraveling The Mystery of Auditory Processing Disorder.
New York, NY: Simon & Schuster.
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DeBonis, David A., et. al (2008). Auditory Processing Disorders: An Update for Speech-Language
Pathologists. American Journal of Speech-Language Pathology, 17, 4–18.
THANK YOU!
Jennifer Saliba