An Overview of (Central) Auditory Processing Disorder – One Audiologist’s perspective

1
An Overview of (Central) Auditory Processing
Disorder One Audiologists perspective

• Dimitra Loomos, Au.D., FAAA, CCC-A
• Audiology Consultant
• www.auditorypathways.com
• The Star Academy
• San Rafael, CA
• March 11, 2011

2
OBSERVED BEHAVIORS

• Distracted by background sounds
• Trouble with multiple directions
• Difficulty comprehending simple oral directions
• Misunderstands what was said
• Appears to have selective hearing

3
Historical Perspectives

• Monaural low redundancy speech tests
• Ettore Bocca, ENT specialist in Italy in the
  mid-1950s,
• Contralateral ear effect
• Binaural interaction/binaural integration tests
• Donald Broadbent, Research Psychologist, 1954,
• The role of auditory localization
  in attention and memory span, Journal of
  Experimental Psychology.
• Helmer Myklebust, after extensive work in hearing
  and speech disorders, Professor Myklebust became
  a pioneer in the field of Learning Disabilities
• auditory imperception in children
  w/communication disorders, Auditory disorders in
  children A manual for differential diagnosis,
  New York, Grune Stratton, 1954.

4
Historical Perspectives

• Dichotic speech tests
• Doreen Kimura, Behavioral Neuroscientist,
  in the 1960s,
• Used dichotic technique to provide
  information on the
• functional differentiation of the
  right and left temporal lobes.
• Jack Willeford, Audiologist at Colorado State
  University in the
• mid-1970s, began to test children
  with Bocas tests as
• well as developing new tests
• Temporal processing tests
• Marilyn Pinheiro, Neuroscientist, in the
  1970s, 80s,
• and early 90s. Used these tests to
  study auditory pattern
• perception in split-brain patients.
  

5
Is There Evidence for APD as a Disorder?

• the quality and quantity of scientific evidence
  is sufficient to support the existence of APD as
  a diagnostic entity to guide the diagnosis and
  assessment of the disorder and to inform the
  development of more customized, deficit focused
  treatment and management plans.
• ASHA,
  2005

6
What is (Central )Auditory Processing?

• The perceptual processing of auditory information
  in the CNS and the neurobiological activity that
  underlies that processing and gives rise to
  electrophysiological auditory potentials.
• The Technical Report
  of the
• ASHA
  Working Group on
• Auditory
  Processing Disorders (2005)

7
Neurobiological Activity

• Mechanisms by which the neuron changes the signal
  from what it was to what it now is processing.
  Tonotopic organization intensity coding, number
  of neurons firing type of neuron firing, etc.
• Neural synchrony, quantity of neurons responding,
  amount of myelin, excitatory synaptic strength.
• Parallel and hierarchical processing occurs
  throughout the CANS. The system is redundant.
  Multiple representations within the system.

8
What is (C)AP?

• (C)AP refers to the efficiency and
  effectiveness by which the central nervous system
  (CNS) uses auditory information.
• 
  Frank Musiek, Ph.D.
• 
  Professor of Audiology
• 
  University of Connecticut

9
What exactly does the nervous system do?

• Codes what the signal looks like
• Rapid spectral changes inherent in speech
• Encoding of acoustic features of speech-sound
  structure
• Timing cues
• Frequency coding
• Intensity coding
• Duration of signal
• Conduction of impulses

10
(No Transcript)
11
Sound is Temporally Structured

• Temporal aspects determine pitch (periodicity)
• Time determines phoneme distinctions (VOT is a
  gap in sound detected when a consonant is
  correctly IDed)
• Slow amplitude modulations determine prosody
• With only minimal spectral information, speech is
  still understandable (adult with normal hearing
  language)
• Temporal processing deficits have been proposed
  in SLI and reading disorder
• Measures of temporal processing
• - Gap detection
• - Categorical boundaries between phonemes
• Michael M. Merzenich (1),  William M.
  Jenkins,  Paul Johnston,  Christoph Schreiner, 
  Steven L. Miller,  Paula Tallal (1996). Temporal
  Processing Deficits of Language-Learning Impaired
  Children Ameliorated by Training. Science, Vol
  271, No. 5245, pp 77 - 81.

12
Major subdivisions of the neural auditory system
APD versus (C)APD

• Organ of Corti
• Auditory or 8th nerve
• Cochlear nuclei
• Superior olivary complex
• Inferior colliculus
• Medial geniculate body
• Auditory cortex

13
Auditory or 8th Nerve

• Breaks down signal from Organ of Corti into
  acoustic features by phase-locking, tonotopic
  organization, adaptation, and suppression for
  relay to higher CANS structures.

14
Cochlear Nuclei

• Receives ipsilateral fibers
• Contrast enhancement of signal modulations and
  transients
• Extracts acoustic features from convergence and
  divergence of pathways and differential cell
  responses

15
Superior Olivary Complex Nuclei

• Codes binaural acoustic cues from convergence and
  divergence of ipsilateral and contralateral
  cochlear nuclei pathways for localization and
  lateralization of sound, and binaural summation
  of acoustic input

16
Inferior Colliculus Nuclei

• High level of information processing
• Further enhances amplitude modulations and
  binaural cues
• Divides ascending pathway into primary and
  diffuse auditory systems
• Contributes to integration of audition with
  visual-motor functions for reflexive responses

17
Medial Geniculate Body

• Primary rely station for information between
  brainstem and cortex high level of signal
  processing
• Codes stimuli with slowly changing acoustic
  features (i.e., vowels and syllable contrasts
  differing in duration)
• Additional binaural encoding
• Contrast and modulation enhancement
• Feature extraction
• Complex signal processing
• Multimodality integration
• Integration of complex auditory patterns with
  reticular activating system

18
Primary Auditory Cortex

• Coding of rapid acoustic events (time-based sound
  patterns) necessary for fine-grained
  discrimination, especially of consonant stimuli
• Frequency and intensity encoding occurs secondary
  to aggregate input from a population of neurons
• Development of the concept of auditory space for
  localization of a sound source in space

19
Left Hemisphere

• Dominant for analytic function phonological
  analysis and discrimination
• Sequencing auditory input
• Performing linguistic labeling

20
Right Hemisphere

• Dominant for gestalt function perception of
  nonverbal sounds and musical and prosodic stimuli
• Rhythm and stress
• Perception of acoustic contour in both verbal and
  nonverbal signals
• Auditory patterning and temporal ordering

21
Auditory Association Cortex

• Recognition of linguistic stimuli
• Comprehension of spoken language
• Some language formulation capacity

22
(Central) Auditory Processing Deficit

• Auditory information comes at you rapidly.
• If the listener cannot process it fast enough,
  he/she will fall apart.

23
Two Basic Premises for Processing

• Bottom Up
• How information is carried from the ear to
• the brain.
• Top Down
• How information is acted on once it gets
• to the brain.

24
Mechanisms in CANS give rise to the following
auditory functions

• Sound localization and lateralization
• Auditory discrimination
• Auditory pattern recognition
• Temporal integration, temporal discrimination,
  temporal ordering, temporal masking
• Auditory performance with competing acoustic
  signals
• Auditory performance with degraded acoustic
  signals
• 
  ASHA 2005

25
What is (central) auditory processing disorder
(dysfunction, deficit)?

• Ineffective and/or inefficient use of auditory
  information by the CANS.
• The analysis, encoding, storage, and/or
  organization of acoustic features is defective.

26
Functional Behaviors

• Working toward an authentic assessment
• Incorporate observations of auditory behavior in
  the classroom and content areas of behaviors
• Childrens Auditory Performance Scale
• (CHAPS) from Educational Audiology
  Association (www.edaud.org)
• Screening Inventory for Targeting Educational
  Risk (SIFTER) also at www.edaud.org

27
Categories of Audiological (C)AP Tests

• Temporal
• Dichotic
• Auditory Discrimination
• Binaural Interaction
• Monaural Low-Redundancy
• Auditory Evoked Potentials (electrophysiologic
  assessment)

28
Electrophysiologic Assessment

• Pros
• By-pass language processing
• No issues with motivation
• May be unique measure of the system and
  improvement
• Cons
• Lacks functional link speculative
• Disease model
• Cost/benefit

29
(C)APD Impacts these Auditory Functions

• Sound localization and lateralization
• Auditory discrimination
• Auditory pattern recognition
• Temporal (timing) aspects of sound
• Auditory performance with competing acoustic
  signals
• Auditory performance with degraded acoustic
  signals

30
Take Home Message 1

• Over the past 50 years, appropriate auditory
  tests have been developed to diagnose (central)
  auditory processing disorder (dysfunction,
  deficit).

31
Test Battery

• An efficient and practical test battery taps into
  as many auditory mechanisms as possible. One test
  does not do it all.
• Low language and low cognitive loads
• Non-verbal tests when possible
• Pre-recorded on CDs
• Administered through a two-channel audiometer
• Listening through calibrated earphones in a sound
  attenuated booth

32
Is a (C)AP evaluation the same thing as a hearing
test?

• No. But, normal peripheral hearing sensitivity
  must be proven before the results from a (C)AP
  test battery can be meaningfully interpreted.

33
Take Home Message 2

• Diagnosis of (C)APD can be applied when a
  perceptual deficit is demonstrated in other
  modalities, if the CANS dysfunction is documented
  by appropriate testing.
• Differential diagnosis exceedingly important and
  can be quite challenging

34
Take Home Message 3

• Only an audiologist, who is trained and
  experienced in (central) auditory processing
  assessment, can rule out all degrees of
  peripheral hearing loss as well as determine how
  well the auditory system functions from the
  external ear to the auditory cortex.

35
Types of Potential Neurophysiological Dysfunction

• Interhemispheric transfer deficits
• Insufficient hemispheric lateralization
• Imprecise synchrony of neural firing
• Decreased central inhibition

36
Causes of (Central) Auditory Disorder/Deficit/Dysf
unctionAbnormal Neurophysiologic Representation
of Auditory Stimuli

• Maturational
• Inefficient neurophysiological
  representation
• Imprecise temporal processing
• Abnormal hemispheric representation
  transfer
• Neuromorphological
• The wiring is not right (e.g. ectopic
  areas in auditory cortex)
• Neurological (Including Acquired)
• Neurological diseases, disorders (e.g.
  Landau-Kleffner), toxins,
• trauma and insults, including
  neurodegenerative diseases
• Aging
• Noise exposure
• The etiology may also be genetic, congenital or
  related to sound deprivation.

37
Who is at risk for CAP deficits?

• Children or adults with a history of learning
  disabilities, ADHD or ADD, speech or language
  disorder, family history of CAP deficits, known
  neurological disorder, head trauma, or recurrent
  otitis media are at risk.

38
Issues critical to children with (C)APD

• Children spend 45-60 of their days with the
  primary focus on listening
• Ability to recognize speech in quiet is a poor
  predictor of how efficiently and effectively they
  can listen with competing noise.
• Immature auditory and language systems just based
  on age alone.

39
JUST A FEW OF THE THINGS THAT INTERFERE WITH
AUDITORY PROCESSING

• BACKGROUND NOISE
• NOISE WITHIN THE SPEAKER
• NOISE WITHIN THE LISTENER
• NOISE IN THE VISUAL FIELD
• CLARITY AND LOUDNESS OF THE SPEAKERS VOICE
• THE ROOM AND LISTENING ENVIRONMENT

40
Classroom as listening environment

• Background noise
• Reverberation
• Signal-to-noise ratio

41
Implications of Signal-to-Noise Ratio

• Adult listeners need at least a 6
  signal-to-noise ratio for maximum receptive
  communication.
• Children with normal hearing acuity and no CAPD,
  need at least a 10 signal-to-noise ratio for
  maximum receptive communication.

42
Implications of Signal-to-Noise Ratio

• Children with high risk listening conditions need
  12 to 20 signal-to-noise ratio for maximum
  receptive communication.

43
When is a (C)AP evaluation needed?

• Children with suspected or confirmed learning
  problems and not benefiting from therapy or
  classroom instruction might have a (C)AP deficit.
  Knowing if an auditory component exists and, if
  so, which specific auditory functions are
  deficient, can lead to more effective management
  strategies.
• Adult neurological populations with verbal
  information processing problems.

44
Differential Diagnosis

• Verbal information processing problems can result
  from an auditory processing problem, a language
  processing problem, a combination of the two,
  and/or deficits in cognitive decision making or
  memory or attention or emotional factors

45
Nature of CAPD

• Cannot be attributed to peripheral hearing loss
  or to higher-order language, cognitive, or
  related confounds.
• May lead to, be associated with, or co-exist with
  difficulties in higher-order language, learning,
  cognitive and communication function.
• But CAPD is not the result of dysfunction in
  other modalities.
• Inappropriate to apply label of CAPD to listening
  difficulties exhibited by individuals with
  higher-order or multimodal disorders (e.g., ADHD,
  autism, cognitive delay) unless a co-morbid
  deficit in the CANS can be demonstrated by
  testing.

46
Comorbidity of Auditory Processing, Language, and
Reading Disorders

• M. Sharma, Ph.D., S. Purdy, Ph.D., and A. Kelly,
  Ph.D., Macquarie University, Sydney, Australia,
  and University of Auckland, New Zealand
• Results 47 with co-occurring APD, LI, RD 10
  with APD RD 10 with APD LI and 4 with
  only APD. Attention and memory were modestly
  correlated with some auditory processing tasks,
  but only explained a minimal amount of the
  variance in scores.
• Journal of Speech, Language, and Hearing
  Research, Vol 52, 706 722, June 2009

47
Some interesting statistics

• 1-2 of general population of LD children have a
  neurological base to any CAPD
• Approximately 60 of LD children have
  auditory-based problems.
• 2-5 of school aged children have CAPD
• Ratio is 21 males to females

48
Differentiating (C)APD from Related Disorders

• History, behavior, symptoms, complaints,
  observation
• Trends from auditory and non-auditory tests
• (i.e., multidisciplinary work up)
• Behavioral auditory testing
• Electrophysiological auditory testing
  (e.g., Evoked Potentials)
• Norm-referenced (inter-subject) comparisons
• Patient-referenced (intra-subject) comparisons
• Laterality (interaural) effects
• MLRs electrode versus ear effects
  amplitude
• ALRs amplitude

49
Differential diagnosis and management of central
auditory processing disorders and attention
deficit hyperactivity disorder.

• Chermak,G.D., Hall,J.W., Musiek, F.E. (1999).
  Journal of the American Academy of Audiology, 10,
  289-303.
• ADHD CAPD
• 1. Inattentive 1. Difficulty
  hearing/noise
• 2. Distracted 2.
  Difficulty following directives
• 3. Hyperactive 3. Poor listening
  skills
• 4. Fidgety 4.
  Academic problems
• 5. Impulsive 5. Poor
  auditory associative skills
• 6. Interrupts 6.
  Distracted
• 7. Poor listening 7.
  Inattentive

50
Take Home Message 4

• Differential diagnosis is very important and can
  be quite challenging.
• Need to involve other professionals to look in
  other areas.

51
Management of (C)APD

• Interventions designed to improve signal quality.
• Interventions designed to improve auditory
  perceptual skills. (AT)
• Interventions designed to enhance the
  individuals language abilities and cognitive
  strategies.
• Use of compensating strategies.

52
Preferential Seating

• Studies have documented a significant loss in
  speech intelligibility unless seated very near
  the teacher.
• 100 at approximately 6 inches from teacher
• 83 front and center
• 55-63 back row of classroom

53
Evidence to support use of FM technology in this
population

• Use of personal FM technology with APD
• ASHA 1990 technical report
• Provide greater signal to noise ratio enhancement

54
Sound-field options

• FM or Infrared depends on the space, the needs,
  etc.
• Front Row to go
• http//www.gofrontrow.com
• Lightspeed
• http//www.lightspeed-tek.com
• Audio Enhancement
• http//www.audioenhancement.com
• Supportive Hearing Systems (Simeon)
• http//fmhearing.com

55
Desktop speaker

• If reverberation is the issue, can be overcome
  with a directional speaker, such as a desktop
  speaker
• Volume is low and reverberation to other students
  is not increased
• Benefits only that individual child

56
Personal FM

• The most effective way to enhance and optimize
  speech audibility for the child

57
Personal FM

• Assumptions
• High risk listeners require an enhanced SNR due
  to the disorder impacting the auditory system
• They receive some benefit from sound-field
  system, but it does not provide the type of
  benefit needed to optimize the environment and
  provide an auditory scaffold for other skills

58
Phonak iSense Receivers

• iSense Micro kindda like a bluetooth
• iSense Classic kindda like a MP3 player
• iSense adapts volume automatically based on the
  level of background noise
• iSenses output stays within safe limits at all
  times

59
Validation of FM fitting

• Specific observations
• Use of a questionnaire such as the Listening
  Inventory for Education (LIFE) available at
  http//www.edaud.org/store

60
Deficit Specific Intervention

• Design and monitor treatment plans aimed at
  improving the patients functional capabilities
  and enhancing the quality of life. Appropriate
  assessment provides the information needed to
  design those plans.

61
Two Basic Premises for Processing

• Bottom Up
• How information is carried from the ear to
• the brain.
• Top Down
• How information is acted on once it gets
• to the brain.

62
Research Supports Reorganization of (C)ANS with AT

• Auditory Neuroscience Lab, Northwestern
  University
• Demonstrated neural timing deficits inherent
  in some learning impaired children using
  speech-evoked ALR
• Demonstrated enhanced cortical neural
  encoding post AT (Earobics) using speech-evoked
  ALR. Those same children improved on speech-sound
  perception measures post AT (WJ-R)
• Demonstrated more robust cortical responses
  to
• speech-in-noise post AT
• Basic encoding of sound structure altered
  secondary to AT
• Physiological changes improvement of neural
  timing
• Hayes, Warrier, Nicol, Zecker, Kraus, Clinical
  Neurophysiology 114 (2003) 673-684

63
Auditory Plasticity Slide Show

• http//www.soc.northwestern.edu/brainvolts/slidesh
  ows/plasticity/index.php

64
Research, Contd

• Elaine Schochat, Ph.D., University of Sao Paulo
• Evaluated differences in behavioral CAP tests
  and amplitude, latency and/or morphology of
  evoked MLRs in APD children pre and post
  auditory training (integrated strategies)
  compared to a control group.
• Demonstrated significantly improved
  performance on behavioral tests and enhanced
  amplitude of MLR post AT for experimental group.
• Indicated more neurons were potentially
  contributing to the generation of the MLR.
• Seminars in Hearing, 19 (4) 359-368, 1998

65
Plastic neural changes and reading improvement
caused by audiovisual training in
reading-impaired children. (Finnish Study)

• Kujala, T., Karma, K., Ceponiene, R., Belitz, S.,
  Turkkila, P., Tervaniemi, M., et al. (2001).
  Proceedings of the National Academy of Sciences,
  USA, 98(18), 10509-10514.
• Trained 7 year old reading impaired children on
  auditory-visual pattern matching task.
• Series of nonverbal sound patterns varying in
  pitch, duration, and intensity.
• Task was to match a sound pattern to a
  corresponding visual pattern.
• Post therapy testing indicated significant
  improvements in reading accuracy and speed, and
  significant increase in the MMN (another type of
  ALR) response to tone-order reversals.

66
Plastic neural changes and reading improvement

• Authors concluded
• Reading difficulties can be treated with special
  training programs
• Training effects are observed in brain activity
• Training program used no linguistic material
  which indicates dyslexia at least partly based on
  auditory perceptual deficit

67
The effect of practice on low-level auditory
discrimination, phonological skills, and spelling
in dyslexia.

• Schaffler, T., Sonntag, J., Hartnegg, K.,
  Fischer, B. (2004). Dyslexia, 10(2), 119-130.
• Large group of dyslexic listeners trained on five
  auditory tasks (intensity and frequency
  discrimination, gap detection, temporal order
  judgments, and lateralization).
• 80 of subjects improved on any given task,
  meeting age-matched controls.
• Perceptual gains accompanied by significant
  improvements in phonemic discrimination and
  spelling.

68
Take Home Message 6

• Auditory training has been shown, using
  behavioral (C)AP tests and electro-physiological
  procedures, to change the CANS and auditory
  behaviors.
• Related measures of language, learning, and
  reading may also document changes in more global
  language, communication, and reading function.

69
Direct Treatment Approaches

• Neurophysiologic basis for AT
• Key Words Adaptive and Challenging
• Exploiting neuroplasticity
• Degree of neuronal change related to amount and
  type of stimulation
• Critical amount of training varies across
  individuals and tasks

70
American Academy of Audiology Clinical Practice
Guidelines - Therapy

• Varying stimuli and tasks
• Age and language appropriate
• Present stimuli at comfortable level (or slightly
  louder and slower)
• Present tasks systematically and graduated to
  keep them challenging and motivating set goals
• Focus work near the skill threshold (30/70 rule)

71
American Academy of Audiology Clinical Practice
Guidelines - Therapy

• Target moderate degree of accuracy before moving
  to a more demanding task
• Use generous feedback and reinforcement
• Acoustic control

72
American Academy of Audiology Clinical Practice
Guidelines - Therapy

• Provide intensive practice
• frequency
• length of training sessions
• number of training sessions
• time intervals between sessions
• period of time over which training occurs

73
Examples of Formal Auditory Training

• FastForWord
• Children with specific language impairment/CAPD
  have difficulty processing brief acoustic events
  occurring in rapid succession (e.g., running
  speech)
• Adaptive, computer based, Center based

74
Examples of Formal Auditory Training

• Earobics
• Addresses a range of skills consistent with
  those reported in ASHA position statement
• Product now marketed as focusing on reading
  skill development
• Home and Center versions

75
Examples of Formal Auditory Training

• Temporal Training
• Gap perception vary number of gaps and
• duration
• Frequency Modulation same/different
• Pattern Constellations
  identification,
• 
  discrimination
• 2 Element Ordering
• Duration Discrimination

76
Examples of Informal Auditory Training

• Temporal cueing re Segmenting
• The judge went to the
  fairgrounds for a divorce. Versus The judge said
  he saw fair grounds for a divorce.
• Homework was the drawback in
  high school.
• Versus Randy learned to draw back in high
  school.
• Duration and Juncture - nitrate
  versus night rate it sprays versus its
  praise

77
Examples of Informal Auditory Training

• The Simon Game
• played without visual cues
• label tones
• identify a sequence of tones

78
Examples of Informal Auditory Training

• Prosody Training
• Keyboard training pattern length, interval
  between stimuli, speed, element duration, cadence
• Syllabic stress heteronyms (e.g.,
  project vs.
• project)
• Prosodic alterations within sentences

79
Examples of Informal AuditoryTraining

• Prosody Training
• Tone of voice (Knock, knock jokes)
• Key word extraction
• Reading aloud with exaggerated prosodic
• features

80
Examples of Informal Auditory Training

• Auditory Closure Training
• Missing word exercises
• Missing syllable exercises
• Missing phoneme exercises
• Speech-in-noise training

81
Examples of Informal Auditory Training

• Phoneme Training
• Short versus long vowels
• Minimal contrast pair discrimination
• Discrimination in context (syllables, words)
• Segmentation, blending, and related skills
• Speech-to-print skills

82
Examples of Informal AuditoryTraining

• Lindamood-Bell materials
• LiPS
• Seeing Stars
• Visualizing Verbalizing

83
Examples of Informal AuditoryTraining

• Auditory Vigilance
• Localization
• Memory (AME)
• a sketch for each segment
• represent key concepts
• review sketches and tell the story
• Music Training

84
More Examples of AuditoryTraining

• Dichotic Interaural Intensity Difference (DIID)
  training
• building the less dominant ear (Musiek)
• Aural Rehabilitation for Interaural Asymmetry
  (ARIA)
• similar protocol to DIID with more data to be
• commercially available, probably this
  year (Moncrieff)

85
Auditory Training for head trauma

• Frank Musiek, Ph.D., University of Connecticut
• Case study Assessment and remediation of
  APD
• associated with head trauma in an adult.
• Integrated therapy strategies (clear speech,
• reauditorization, dichotic interaural
  intensity difference
• training, auditory memory enhancement,
  speech
• discrimination training, temporal sequence
  training)
• Post therapy testing improved MLR
  amplitude and
• morphology for both ears significant
  improvement on
• behavioral CAP tests.
• Jour. Amer. Acad. Audiology, 15117-132
  (2004)

86
Autobiographical Account

• The brain was primarily distorting
• information from the left ear, although some
• additional distortion occurred in the left
• hemisphere as well.
• Gifts from the Broken Jar by P. J. Long
• www.equipress.com

87
Ecological Approach to Intervention

• As individuals mature, the number and variety of
  contexts in which they need to function
  increases.
• New challenges/difficulties may emerge with
  changing contexts these should be evaluated and
  considered within the context of the individuals
  management plan.

88
Ecological Approach to Auditory Training

• Design and monitor treatment protocols aimed at
  improving the patients functional capabilities
  and enhancing the quality of life.

89
Looking to the Future

• Instrumentation for sophisticated stimulation and
  analysis of brainstem and cortical responses
• Correlations among behavioral (C)APD findings,
  AER patterns, and fMRI confirmation of anatomic
  activity
• Documentation with AER findings of the effects of
  intervention for (C)APD

90
Mentors and Researchers

• Frank Musiek, Ph.D., University of Connecticut
• James Hall, Ph.D., University of Florida
• Gail Chermak, Ph.D., Washington State University
• Terri Bellis, Ph.D., University of South Dakota
• Jeanane Ferre, Ph.D., Private Practice, Oak Park,
  Illinois
• Nina Kraus, Ph.D., Northwestern University
• Suzanne Purdy, Ph.D., University of Auckland, New
  Zealand
• Elaine Schochat, Ph.D. School of Medicine, Sao
  Paulo University, Sao Paulo, Brazil
• Mridula Sharma, Ph.D., Macquarie University,
  Sydney, Australia
• Jennifer Shinn, Ph.D., University of Kentucky
• Jane Baran, Ph.D., University of Massachusetts
  Amherst