The ABCs of CAPD: The Connection between Central Auditory Processing Deficits and DyslexiaSusan Snyder, Au.D CCC-A

Assistant Professor

Audiologist

Speech Language and Hearing Clinic

Department of Speech Language Pathology

Duquesne University

Learning Objectives

To understand what is Central Auditory

Processing Disorders (CAPD)

To understand how CAP is assessed and general

understanding of results

Present current research on CAPD and Dyslexia

Current Therapy and Remediation Approaches

Anatomy: First things first!

We Have to Check the Ears!!

Initial input

HL, OM, ceremunetc.

Division Mode of operation Disorder

1. Outer Ear Air vibration Conductive HL

2. Middle Ear Mechanical Vibration Conductive HL

3. Inner Ear Mechanical,

Hydrodynamic

Electrochemical

Sensorineural HL

4. Central Auditory

Nervous System

Electrochemical Central Auditory

Processing (CAP)

http://scienceblogs.com/thoughtfulanimal/2010/06/ask_a_scienceblogger_sens

ation.php

Corpus Collosum and Hemispheric

Dominance

Neuromaturation

Ear

Fully developed at 5th month gestation

CANS

Brainstem and auditory pathways are complete by 30 weeks gestation

Brain

Not fully developed at birth and continues to grow until adulthood

What the Difference between CAPD

and HL

Important Terms to know: Audibility

versus Intelligibility

Audibility Intelligibility

Can you hear me now?

Ca u er m no?

Hearing Loss and Literacy

Hearing Loss and Literacy

“ah”

“Walk, walked,

Walks”

Hearing Loss and Literacy

“walk”

Walk, walked,

walks

and

Invisible Acoustic Filter Chain

Hearing Loss

(invisible acoustic filter)

Spoken Language

Reading

Professional Options

Academic Options

1° levels

2° levels

What is CAPD?

… a deficit in the neural processing of auditory stimuli that

may coexist with, but is not the result of, dysfunction in other

modalities.

ASHA (2005). (C)APD Technical Report

CAPD is a “true” clinical disorder and there is established

documentation of the strong link between well defined

lesions of the central auditory nervous system (CANS) and

deficits in behavioral and electrophysiologic central

auditory measures.

AAA (2010) CAPD Taskforce

Simply…

“it is how well the ear talks to the

brain, and how well the brain

understands what the ear tells it”

-Frank Musiek, Ph.D CCC-A

CAPD IN PEDIATRIC POPULATION

Diseased or injured CANS<5%

Maturational Delay ~25-30%

Disorganized CAPD 65-70%

Prevalence:

2-5% of school aged population

2:1 ratio of boys to girls

Chermack and Musiek, 1997

Age of Testing

7 years of age or older for functional and electrophysiological testing

<7 years only electrophysiological (or site of lesion)

Speech Intelligibility Have adequate speech production

Multiple articulation errors can interfere with testing

Cognitive Abilities

Normal intelligence

Not more than 1.5 SD from norm

Ability to follow complicated directions

Elderly: check for decreased memory or attention

Knowledge of concepts

(Jerger, 2000, p. 467-8 Technical Assistance Paper, 2001)

Language Competencies to perform

(C)APD Tests

Language age > 6 years or better

Rule out language processing

English as primary language

If non native speaker use elcetrophysiologic measure, dichotic digits or non

verbal stimuli

Limited tests in other languages

(Keith, 1986, p.11. Technical Assistance Paper, 2001, pg 5)

Pre Existing Considerations

Identified disability

Conditions that have impact on auditory skills should be ruled out

(Jerger, 2000, p.467-8; Technical Assistance paper, 2001, pg5)

Audiologist should be last to test

Categories of Audiological CAP Tests

Temporal

Dichotic

Auditory Discrimination

Binaural Interaction

Monaural Low-Redundancy

Auditory Evoked Potentials (electrophysiological assessment

Electrophysiological Assessment

Pros:

By-pass language processing

No issue with motivation

May be unique measure of the CANS

Cons:

Lacks functional link

“Disease model”

Cost/benefit

Common Indicators for (C)APD

Demonstrates significant scatter across subtest with domains assessed by

speech language and psychoeducational tests, with weakness in auditory

dependent areas

Common Indicators for (C)APD

Behaves as if hearing impaired despite normal peripheral hearing acuity;

Frequently misunderstands oral instructions or questions

Delays in responding to oral instructions

Says “huh” or “what” frequently

Needs frequent repetition

Has problems in background noise or reverberant acoustic environment

Common Indicators for (C)APD

Verbal IQ lower than performance IQ

Needs high degree of external organization in class

Difficulty following multi-step directions

Exhibits poor reading and spelling skills

May refuse to participate in classroom discussions or responds late

Problems with the ability to localize the source of a signal

Common Indicators for (C)APD

Difficulty hearing on the phone

Inconsistent or inappropriate responses to

request for information

Difficulty following rapid speech

Difficulty or inability to detect the subtle

changes in prosody that underlie humor and

sarcasm

Common Indicators for (C)APD

Poor singing, musical ability, and/or

appreciation of music

Academic difficulties, including reading, spelling

and/or learning problems

Difficulty learning a foreign language or novel

speech materials, especially technical

language

Common Indicators for (C)APD

May be withdrawn or sullen, behavioral problems

Positive hx of COM

Positive history of neurological involvement

Poor singing or music skills

Fine and gross motor skills are weak

Adapted from Cohen (1980), Fisher (1985),Bellis (2003)and AAA Clin Practice Guidelines (2010)

APD Screening/Behavioral Checklists

Auditory Processing Domains Questionaire (APDQ 2012) Fisher’s Auditory Problems Checklist (FISHER , 1985) Children's Auditory Performance Scale (CHAPS; Smoski, Brunt,

& Tannahill, 1998) Screening Instrument for Targeting Educational Risk (SIFTER;

Anderson & Matkin, 1996) Preschool Sifter Listening Inventory for Education (LIFE; Anderson & Smaldino,

1998) Children's Inventory of Listening Difficulties (CHILD; Anderson &

Smaldino, 2000) Classroom observation

Deficit Specific Diagnosis

Auditory Skills

Auditory Awareness:

identify the presence of sound

Localization/Lateralization:

location of sound

Auditory Recognition:

recognizing what a sound is

Auditory Attention:

sustain attention for age appropriate amount of time

Auditory Discrimination:

Identify the differences among sounds of different frequency, duration, or intensity within words

Auditory Closure:

understand whole word or msg when part is missing

Auditory Figure Ground:

Identify primary linguistic or non linguistic sound source from BGN

Auditory Skills

Auditory Short Term Memory:

Retain auditory info as it is immediately presented

Auditory Sequential Memory:

Recall the specific order of series or details

Temporal Resolution:

Timing/pattern characteristics of a sound sources

Binaural Listening:

Ability of the brain to listen to both ears and how well both ears work together

Integration and separation

Auditory Synthesis:

ability to merge or blend isolated phonemes into words –critical for reading

Binaural Listening

YAHOO!!

Binaural Listening

Amblyaudia or Lazy Ear

Amblyaudia is a term coined from amblyopia

Deborah Moncrieff, Ph.D CCC-A

Results suggest problems with dichotic listening

Can only see when both ears are challenged at that the same time

Ear Infection Today… Lazy Ear

Tomorrow

Investigator: hearing scientist Jonathon Whitton and Daniel Polley, Ph.D

from Massachusetts Eye and Ear

Results; found by inducing a brief, reversible hearing loss at key milestones

in cortical development, they identified two critical periods occurring after

hearing onset that regulate the maturation of coordinated binaural sound

representations.

"The good news about amblyaudia is that it is unlikely to be a permanent

problem for most people," concludes Dr. Polley. "Even if the acoustic signal

isn't improved within the critical period, the mature auditory cortex still

expresses a remarkable degree of plasticity

What is the difference between CAPD

and Language Processing?

The Processing Continuum Model:

Assessment

CANSCentral Auditory

Processing

Heschl’s

GyrusLanguage Processing

Assessed by SLP

Transition Area

Both Auditory & Language Processing

Assessed by both SLP and Audiologist

(Richard, G 2001, The Source for Processing Disorders)

Assessed by

the Audiologist

Auditory Skills Executive Functions

Other Co-existing Disorders (Co-

morbidity) Peripheral HL

Specific learning disability (SLI)

Learning disabilities (LDs)

Reading disorders (dyslexia)

Attention Deficit/Hyperactivity Disorders (ADHD)

Emotional and psychological disorders

Developmental delays

Seizure disorders

PDD, ASD

https://www.brainvolts.northwestern.edu/slideshows/reading/index.php

Neurological Evidence of the Links

between CAPD and Dyslexia

7.5% of kindergartners exhibit significant delays in oral language skills (language learning

impairment)(Tallal and

Heim, 2015)

LLI

• Difficulty in tasks requiring precise rapid auditory processing (Heim et al, 2013)

Dyslexia

• Children with LLI are highly susceptible to reading failure, dyslexia (Tallaland Heim, 2015)

CAPD and Dyslexia

Research continues to confirm CAPD is a fundamental problem

contributing to both LLI and dyslexia.

Recent research has pointed to acoustic, memory, and language functions

as contributing to the complexity of the impairment.

The Overlap of ADD, Dyslexia and

CAPD

Attention is controlled by the frontal lobe and the frontal lobe is responsible

for higher cognitive functions such as planning and organization

Frontal lobe doesn’t reach maturity until late 20s

Both adults and children with ADHD have lower levels of frontal lobe

activity

Attention/CAPD: need attention to sort thru sensory data around you and

pick out what's relevant

Open vs Focused Attention

ATTENTION IS LEARNED

Open

Babes & kids

Pay attention to everything

Can’t focus

Focused

Goal driven to learn something

Biased attention- learn some info is more relevant than other and pay more attn.

Differential Diagnosis (Chermack, et al,

1998)

ADHD

Inattentive

Distracted

Hyperactive

fidgety/restless

Hasty/ implusive

Interrupts/intrudes

CAPD

Difficulty hearing in BGN

Difficulty following oral instructions

Poor listening skills

Academic difficulties

Poor auditory association

Distracted

inattentive

Source: Richard, G, The Source for Processing Disorders, LinguiSystems, Inc, 2001

Still needs more research on the

effect on (C)APD by:

Cooperation

Motivation

Attention

Children with family history of dyslexia

Children with family history of dyslexia show lower activity in sensory regions

of the brain and difficulty with speech processing even before they learn to

read

Raschle et al., PNAS Feb 7, 2012

The Complex Interaction

Neurodevelopment of language skills and ultimately the ability to benefit from reading instruction

Linguistic

Auditory

Visual

All the lobes

www.braindrain3.com

Statistical parametric maps showing brain activation during phonological processing (FSM >

VM) for children with (A) and without (B) a familial risk for DD, as well as group differences

between children with compared to without (FHD− > FHD+) a fam...

Nora Maria Raschle et al. PNAS 2012;109:6:2156-2161

©2012 by National Academy of SciencesRaschle et al., PNAS Feb 7, 2012

Neural effects of remediation in children with developmental dyslexia.

Elise Temple et al. PNAS 2003;100:5:2860-2865

©2003 by National Academy of Sciences

https://www.brainvolts.northwestern.edu/slideshows/reading/index.php

Rhythm

Overview of Research on the Neurobiology

of Reading and Reading Impairment

Scientific community currently agrees;

That a neurologically based phonological coding deficit as well as other types of

language problems underlie most problems learning to read (Shaywitz et al.,

1998; Snow, burns, & Griffen, 1998; Vellutino, Fletcher, Snowling, & Scanlon, 2004;

Boetz 2014)

Recent brain function studies indicate early structural connectivity differences in

at-risk prereaders that involve auditory, language and visual brain regions. This

may cause difference at older age with a complex pattern of reading problems

(Saygin et al., 2016; Vandermosten et al., 2015, Vandermosten, Hoeft, & Norton,

2016)

Research

Brains of dyslexic adults examined on autopsy showed embryonic cellular collections in the language regions of the left hemisphere

•When the same embryonic cells were induced in animals it caused temporal processing deficits

• Galaburda, 1994; Galaburda, Menard, & Rosen, 1994;Peiffer,Friedman, Rosen, & bFitch, 2004

MEG studies of adults with poor reading abilities showed electrophysiological evidence of difficulty with rapid processing in the auditory cortex

• (Nagarajan et al., 1999

Electrophysiologic studies of children with lang and reading problems revealed deficiencies in neural synchrony(timing deficits) in subcortical as well as cortical regions that process speech sounds perception and measures of learning

• Kraus, 2001

Further research

fMRI studies of dyslexic adults and children revealed the cortical neurological structures in the left hemisphere that support language learning and working memory also support reading

•Temple et al., 2000; Temple et al., 2003

fMRI studies have further indicated that as children learn to read they first rely on temporal parietal/occipital regions of the left hemisphere that underlie phonological awareness and other aspects of oral language comprehension

•(Shaywitz et al., 2014; Vandermosten et al., 2016)

fMRI studies have shown that as children become proficient in reading, other regions of the left hemisphere that are active in auditory memory and language production become part of a reading network

•(Shaywitz et al, 2004)

Electrophysiological studies of young children w/ a family hx of specific language impairment show temporal processing differences in mismatched negativity (MMN) and N₂₅₀ERP waveforms to rapid auditory stimuli as early as 6 months of age.

• When followed at 48 and 60 months, poor processors showed significant reductions in language measures compared to age matched peers with no rapid auditory processing deficits

•(Benasich, 2006;Benasich & Tallal, 2002)

Musical training improves non verbal rapid spectro-temporal processing as well as changing the neurotemporal network invoked in spectro-temporal processing

•The changes overlap primarily with Broca’s area, the brain area in the frontal lobe associated with language processing

•(Gaab et al, 2005)

Several genes that have been linked to developmental dyslexia affect brain development specifically auditory and cognitive deficits associated with dyslexia

• (Calaburda, LeTurco et al, 2006; Ozernov-Palchik et all., 2016)

Studies show gamma activity in infants indicates a measure of early sensory information (possible link to top-down processing)

• Gamma power at 24 and 36 correlate with Non-Word Repetition Test and PLS-3 and CELF-P

•Gou, Choudhury, & Benasich, 2001)

Some dyslexic children who tested abnormally on electrophysiological testing had normal results on common CAPD tests and vis versa.

They recommended testing both on all children.

• Billet & Bellis, 2011

A study of 42 adolescent and adults found auditory deficits for speech and non speech auditory stimuli in most, but not all, participants.

• Concluding that the results supported the existence of a general auditory processing impairment in developmental dyslexia

• (Christmann et al, 2015)

Research

Concluded that children with LLI showed impaired temporal sampling of a speech signal

• Also other research hsowed impaired syllable perception (2012)

• Usha Goswana et al (2016)

Studied audiovisual synchrony in adults with dyslexia and showed a wider time window for audiovisual synchrony

• Concluded that their results point towards the presence of a domain-general audiovisual temporal processing deficit in developmental dyslexia

• Francisco et al., (2017)

Effect of Auditory Processing

Remediation in Reading Achievement

1990s

• When the addition of rapid auditory processing training and the inclusion of acoustically modified speech and language intervention, resulted in significant improvement in language, auditory, and speech discrimination vs children with just language intervention

• Tallal and Merzenich 1990

Nina Kraus research

• 2001- changes in cortical potentials in children who underwent computer based auditory training programs

• 2015- preschoolers who gave difficulty processing in noise have problems with phonological awareness

Music

Stable foundation for other auditory functions

Music facilitates sound to meaning learning for non

musical tasks

Music is biologically powerful and it can make changes

to our nervous system throughout our lives

Educational implication are enormous

Musical experiences enhances auditory based READING

skills

Nina Kraus: Music for the development

of auditory skills

https://www.youtube.com/watch?v=Yp32um7VVe0

Musical Experience

Influence of cochlea (hair cells) up to brain

Sound to meaning experience, i.e parent recognize child’s cries

Ongoing studies on long term effect of musical

experiences on learning and reading, short term

memory and effects on older individuals' ability

to listen in noise

Nina Kraus: Music for the development

of auditory skills

https://www.youtube.com/watch?v=Yp32um7VVe0

Summary of Research

Temporal processing in general, and rapid

auditory processing impairments specifically,

are correlated with language and reading

disorder in children and adults

The degree to which these disturbance are

causative is still debated but genetic and

longitudinal studies are beginning to point to at

least a partial causative relationship.

Summary of Research

Auditory processing skills, especially rapid auditory

processing underlie language acquisition and reading

mastery

Specifically, rapid AP at cortical and subcortical levels

present a core components of phonological

awareness and therefore decoding of words

What can we do now? CAP Training

Programs

Intervention Components

Bottom up (stimulus driven)

Direct auditory skills remediation

Environmental modification

HATs

Top Down (strategy driven)

central resource training

Educational interventions

Workplace , recreational and home accommodations

Intervention Principles

Intensive training to exploit the plasticity and

cortical reorganization

Extensive central resources (multidisciplinary)

training to exploit large, shared, and

overlapping auditory, cognitive, metacognitive,

and language systems, and maximize

generalization and effectiveness

Active participation, with reinforcement

Fast ForWord-use for temporal processing issues and auditory discrimination issues

- Children thru adults

- At home, neuroscience based reading intervention program for AP, dyslexia and reading struggles

-Neuroscience approach:

-practice/repetition

-Attention

- working memory

- Evidence based research

- Examples of Exercises: Phoneme identification, grammar and language, rapid auditory listening skills, reading of words quickly, comprehension, complex sentences, antonyms, analogies and reading comprehension.

Fast ForWord continued

Children who receive this therapy show:

Improvement in standardized receptive language testing

Increase in the effects of attention and neural processing

Significant that selective auditory attention can be improved through training and correlate with improvements in standardized measures of language

fMRI studies of dyslexic children using Fast ForWord Language Training

program after 6 weeks showed significant increase in reading and

language without reading intervention at the same time

Other Listening Program

Jack Katz’s Phonemic Synthesis Program

Works on phonemic awareness

Earobics

Great program but not supported with newer editions of windows software

Ear Infection Today… Lazy Ear

Tomorrow

Investigator: hearing scientist Jonathon Whitton and Daniel Polley, Ph.D

from Massachusetts Eye and Ear

Results: found by inducing a brief, reversible hearing loss at key milestones

in cortical development, they identified two critical periods occurring after

hearing onset that regulate the maturation of coordinated binaural sound

representations.

"The good news about amblyaudia is that it is unlikely to be a permanent

problem for most people," concludes Dr. Polley. "Even if the acoustic signal

isn't improved within the critical period, the mature auditory cortex still

expresses a remarkable degree of plasticity

Binaural Therapy Techniques:

An auditory training procedure that seeks to improve a psychoacoustic skill

that receives contribution from the CANS

Based on depriving the stronger ear so the weaker ear can improve

Applicable to unilateral or asymmetrical dichotic differences

Candidacy for Dichotic Training

Must be over 7 years of age

Normal peripheral hearing sensitivity

Interaural SRT no greater than 10 dB

A unilateral or asymmetrical dichotic processing deficit

Intensity of the stimulus presentation to the stronger ear cannot be below the level of audibility at the cross over point

Dichotic Interaural Intensity Difference

Protocol (DIID)

Background:

Auditory Rehabilitation for Interaural

Asymmetry (ARIA)

By Deborah Moncrieff, Ph.D CCC-A

Dichotic stimuli

Presented via soundfleid

Results have shown an improvement in left ear performance over time

Also an improved language comprehension and word recognition

Constraint Induced Auditory Therapy

(CIAT)

Developed by Annette Hurley, Ph.D and D. Bradley Davis, Au.D, CCC-A of

the Department of Communication disorders, LSU Health Sciences Center

this program is based upon Dichotic Interaural Intensity Difference (DIID)

training

Online therapy solution for

CAPD:

CAPDOTS Integrated

CAPDOTS Selected

Used specifically to treat

binaural integration and

separation deficits

5 years and up

Just need computer and

“test assistant”

Music Education and Reading

Transform sound processing in the brain

Pitch timing is improved by practice

Reading enhancement in children with music class 2X a week

Benefits of auditory attention and auditory memory

Neural encoding of time- rapid timing tasks predict reading as well as

slower timing identification

Poor reader have slower neural timing

The CNS handles the timing and therefore pitch recognition is very

important

Music Education and Reading

Musician are able to identify stop consonants better than non musicians,

i.e. da, ba

Timing delays are less in musicians in noise

LiSN & Learn

Auditory training software developed by NAL

For children identified with spatial auditory processing disorder (SPD)

to hear better in a noisy situation

Identified via LiSN testing

Perform on home computer

Auditory Integration Training (AIT)

Berard, Tomatis and Somonas Sound Therapy

Designed to address auditory sensation deficits; hypersensitivity,

hyposenstivity or misperception

Average level presented was 118 dB SPL (adult)

Children have smaller ear canals so higher SPL expected at eardrum

OSHA level for damage is 85 dB HL

ASHA, AAA, AAP and EAA all say experimental and has not met standards

for safety and need for more scientific evidence

Alternative Sound Based Programs

Berard Auditory Integration®

Tomatis Approach ®

Listening Program ®

Not supported by evidence (only few Level 4 & 5 evidence)

Questionable scientific foundation, poor research design

Potential to cause harm (excessive dB)

Informal Therapy

Informal DIID- Step 1

Present at MCL or ~ 55 dB

HL

Present at a whisper but

still intelligible

Instructions: Tell the child to listen to book only

Adapted from Weihing

Informal DIID- Step 2

Present at MCL

~ 50 dB HLPresent at a whisper but

Still intelligible

Pause after a 1 minute and ask ?s, if above >50% proceed, if significantly

Less or greater than 50%, adjust level of competing signal

or target (laptop computer)

Key Points

As far as brain in concerned: reading is a language

Literacy requires visual decoding but the underlying neurocognitive

requisite of language, including phonological systems and morphologic

systems

Although more studies needed, language and reading problems appear

to stem from CAP problems

Substantial neurological research linking CAPD and dyslexia

After treatment directed at increasing auditory processing speed and

speech sound discrimination, children have shown improvement in several

cognitive domains and more specifically reading

References

AAA (2010) Clinical Practice Guidelines: Diagnosis, Treatment and Management of Children and Adults with Central Auditory Processing Disorders. Retrieved from American Academy of Audiology:

www.audiology.org/resources/documentlibrary/Pages/CentralAuditoryProcessingDisorder.aspx

ASHA (1996). Central Auditory Processing: current status of research and implications for clinical practice. American Jrnl of Audiol, 5(2), 41-54.

McCarty, J. (2014) A Boost for Central Auditroy Processing Disorder Services. ASHA Leader, 19, online only. Doi:10.1044/leader.NIB6.19092014.14

Bellis, T.J. (2002) Assessment and Management of Central Auditory Processing Disorders in the Educational Setting: From Science to Practice. 2nd ed. Delmar Learning Inc.

Bellis, T.J. & Ferre, J.M. (1999). Multidimensional approach to differential diagnosis of central auditory processing disorders in children. Journal of the American Academy of audiology,

10(6), 319-28.

Bellis.T, Richard, G., (2004) Sorting out Processing Disorders-Auditory or Language. Workshop at 2004 ASHA Convention Presentation, Philadelphia, PA

English,K., Martonik,J., Moir,L (2003). An auditory training technique to improve dichotic listening. The Hearing Journal; 56(4): 34-38.

Ferre, J., (2004) Clinical Decision Making in Central Auditory Processing Evaluations, Session at 2004 ASHA Convention, Philadelphia, PA.

Hurley, A & Davis, B. (2011)Informal auditory therapy: What’s on the toy box. The Hearing Journal. 64; 36-40.

Jerger,J &Musiek,F (2000) Report of the Consensus Conference on the Diagnosis of Auditory Processing Disorders in School-Aged Children. J Am Acad Audiol 11, 467-474.

Moncrieff, D. W., Musiek, F. E. (2002, April) Functional MRI of Children During Dichotic Listening, Research podium presented at American Academy of Audiology Convention, Philadelphia, PA.

Musiek, F. (1999) Habilitation and management if auditory processing disorders: Overview of selected procedures. Journal of the American Academy of Audiology; 10;: 329-342.

References

ASHA (1996). Central Auditory Processing: current status of research and implications for clinical practice. American Jrnl of Audiol, 5(2), 41-54.

Bellis, T.J. (2002) Assessment and Management of Central Auditory Processing Disorders in the Educational Setting: From Science to Practice. 2nd ed. Delmar Learning Inc.

Bellis, T.J. & Ferre, J.M. (1999). Multidimensional approach to differential diagnosis of central auditory processing disorders in children. Journal

of the American Academy of audiology, 10(6), 319-28.

Bellis.T, Richard, G., (2004) Sorting out Processing Disorders-Auditory or Language. Workshop at 2004 ASHA Convention Presentation, Philadelphia, PA

English,K., Martonik,J., Moir,L (2003). An auditory training technique to improve dichotic listening. The Hearing Journal; 56(4): 34-38.

Ferre, J., (2004) Clinical Decision Making in Central Auditory Processing Evaluations, Session at 2004 ASHA Convention, Philadelphia, PA.

Moncrieff, D. W., Musiek, F. E. (2002, April) Functional MRI of Children During Dichotic Listening, Research podium presented at American

Academy of Audiology Convention, Philadelphia, PA.

Musiek, F. (1999) Habilitation and management if auditory processing disorders: Overview of selected procedures. Journal of the American Academy of Audiolgy; 10;: 329-342.

Additional References

Maria V. Popescu, Daniel B. Polley. Monaural Deprivation Disrupts Development of Binaural Selectivity in Auditory Midbrain and Cortex. Neuron, 2010; 65 (5): 718-731 DOI: 10.1016/j.neuron.2010.02.019Richard, G, (2001) The Source for Processing Disorders, LinguiSystems, Inc.

Fusco, Jennifer MA CCC-SLP http://www.speechdelay.com/testrosetheear3.htm. 2000.

National Institute on Deafness and other Communication Disorders. http://www.nidcd.nih.gov/health/hearing/otitism.asp.

WebMD. http://children.webmd.com/understanding-otitis-media-basics.