1. Auditory Steady State Responses (ASSRs): Pros and Cons for Clinical Use
Advantages (Pros)
Reasonably frequency specific stimuli
Can be used for electrophysiological assessment of severe to profound degree of hearing loss in infants and young children
FDA-approved clinical devices available
Automated analysis
Potential disadvantages (Cons)
Requires very quiet state of arousal
Sedation or anesthesia is often necessary
Limited anatomic site specificity
Analysis difficult with bone conduction stimulation

2. An Important Application of ASSR
Estimation of Frequency-Specific Auditory Thresholds for Infants with in Severe-to-Profound Hearing Loss:
An Important Application of ASSR

3. ASSR Permits Early, Objective, and Confident
Diagnosis of Candidates for Cochlear Implants

4. Auditory Steady State Response (ASSR): New Investigations and New Applications (> 600 Peer Reviewed Publications)
Venail et al (2014). Refining the audiological assessment in children using narrow-band CE-chirp-evoked steady state responses. Int J Audiol, 18, 1-8 (France)
Rampp et al (2014). Viability of intraoperative auditory steady state responses during intracranial surgery. J Clin Neurophysiol, 31, (Germany)
Hatzopoulos et al (2012). Hearing threshold prediction with ASSRs and estimation of correction functions to compensate for differences with behavioral data in adult subjects: Part 1: Audera and CHARTR EP devices. Med Sci Monit, 18, 47-53
Drouillard et al (2014). Pseudohypacusis in children: Circumstances and diagnostic strategy. Int Pedi ORL, Epub

5. Update on Auditory Electrophysiology
Introduction to auditory electrophysiology … 85-years of research and clinical application
Electrocochleography (ECochG) … Much more than just the diagnosis of Meniere’s Disease
ABR … Over 4000 peer-reviewed publications in the past decade alone
ASSR … Filling an important niche in children and adults
Cortical auditory evoked responses … Now we’re really assessing hearing
Summary, Questions & Answers

6. Cortical Auditory Evoked Responses: Objective Measures of Central Auditory System Function
P300 ALR AMLR ABR ECochG

7. Dan Geisler, Ph.D. Discoverer of Auditory Middle Latency Response (AMLR) in 1958
Geisler, C. D., Frishkopf, L. S., & Rosenblith, W. A. (1958). Extracranial responses to acoustic clicks in man. Science, 128,
Cody, D. T. R., Jacobson, J. L., Walker, J. C., & Bickford, R. G. (1964). Averaged evoked myogenic and cortical potentials to sound in man. Annals of Otology, Rhinology, and Laryngology, 73,

8. Auditory Middle Latency Response (AMLR): Analysis
Pa ( ms) Pb
1 mV Na
Amplitude (mV) Nb
PAM
PAM = Post-auricular muscle
100 ms

9. Origins of the Auditory Middle Latency Response (AMLR) (Photograph adapted from F.E. Musiek)
Primary Auditory Cortex
Primary Auditory Cortex
Thalamus (Medial Geniculate Body)
Thalamus (Medial Geniculate Body)

10. Abnormal Patterns of AMLR with Right Hemisphere Lesion Electrode Effect
Right Hemisphere C6
Left Hemisphere C5 Pa Pb V V RE RE Na Na LE LE
Right Ear
Left Ear

11. Sensitivity and Specificity of the AMLR in the Detection of Auditory CNS Dysfunction
Musiek F, Charette L, Kelly T, Lee WW, Musiek R. Hit and false-positive rates for middle latency response in patients with central nervous system involvement. JAAA 10: 1999.
26 adult control subjects and 26 patients with medically confirmed CANS lesions (mostly CVAs and lobectomies)
Two groups matched for hearing status and age
AMLR measured with hemispheric electrode array (C3 and C4)
Latency measured for Na and Pa
Amplitude measured for Na-Pa
ROC curves generated by plotting hit rate by the false-positive rate for different criteria, e.g., absolute latency and amplitude, and differences in these parameters for ipsi versus contra AMLRs

12. Abnormal Patterns for Auditory Middle Latency Response (AMLR) in Patients with Confirmed Temporal Lobe Lesions (Musiek et al, 2007)
AMLR Component (Amplitude in V)
Hemisphere Na-Pa Na Pa
Side of Lesion
Mean
(SD) (0.20) (0.14) (0.24)
Intact Side
Mean
SD (0.21) (0. 15) (0.27)

13. Ear and Electrode Effects in Pediatric Auditory Middle Latency Response (AMLR) Recordings
Weihling J, Schochat E & Musiek F. (2013) Ear and electrode effects reduce within-group variabiliy in middle latency response amplitude measures. International Journal of Audiology, 51,
155 children
Normal peripheral function
Normal central auditory function
No history of psychological, neurological, or learning disorders
Na-Pa amplitude differences were measured for
AMLR C3 – C4 hemispheric electrode recording sites
Left ear – right ear stimulation
Conclusions
Within group variability was significant smaller for relative differences when compared to absolute measures
Electrode effects showed significantly less variability than ear effects
Authors reports normative data

14. Normal Expectations for Electrode Effects in Pediatric Auditory Middle Latency Response (AMLR) Recordings (Weihling, Schochat & Musiek, 2013)

15. Normal Expectations for Ear Effects in Pediatric Auditory Middle Latency Response (AMLR) Recordings (Weihling, Schochat & Musiek, 2013)

16. Documenting Benefits of Auditory Training with Auditory Middle Latency Response (AMLR) Responses
Schochat E, Musiek FE, Alonso R & Ogata J (2010). Effect of auditory training on the middle latency response in children with (central) auditory disorder. Brazilian Journal of Medical and Biological Research, 43,
Subjects
30 children (age 8 – 14 years) with APD
22 children without APD
Diagnosis of APD
Pediatric speech intelligibility (PSI) test
Speech-in-noise test
Dichotic digits test
Dichotic non-verbal test

17. Documenting Benefits of Auditory Training with Auditory Middle Latency Response (AMLR) Responses (2)
Schochat E, Musiek FE, Alonso R & Ogata J (2010). Effect of auditory training on the middle latency response in children with (central) auditory disorder. Brazilian Journal of Medical and Biological Resarch, 43,
Auditory training protocol
Frequency discrimination training
Intensity discrimination training
Temporal (duration) discrimination training
Dichotic Inter-aural Intensity Difference (DIID

18. Documenting Benefits of Auditory Training with Auditory Middle Latency Response (AMLR) Responses (3)
Schochat E, Musiek FE, Alonso R & Ogata J (2010). Effect of auditory training on the middle latency response in children with (central) auditory disorder. Brazilian Journal of Medical and Biological Resarch, 43,
Pre-training click-evoked AMLR C3-A1 Na-Pa amplitudes were smaller in the APD group
0.84 uV for APD group
1.18 uV for control group
8 week period of auditory training for APD group only
Post-training AMLR C3-A1 Na-Pa amplitudes increased significantly to 1.59 uV in the APD group

19. Documenting Benefits of Auditory Training with Auditory Middle Latency Response (AMLR) Responses (Schochat E, Musiek FE, Alonso R & Ogata J, 2010)

20. “Father of Auditory Evoked Responses”
Hallowell Davis, Ph.D.
“Father of Auditory Evoked Responses”
Co-Discoverer of ALR in 1939 and P300 Response in 1965
Davis, H., Davis, P. A., Loomis, A. L., Harvey, E. N., & Hobart, G. (1939). Electrical reactions of the human brain to auditory stimulation during sleep. Journal of Neurophysiology, 2,

21. Auditory Late Response (Cortical)
5mV
P2 (180 – 200 ms)
P1 (50 ms)
Amplitude (mV)
N2 ( ms)
N1 ( ms)
600 ms
Stimulus

22. P300 Response: Classic Oddball Paradigm
Frequent Unattended e.g., 1000 Hz or /da/
P3 (300)* P2
Amplitude (mV)
Infrequent (rare) Attended e.g., 2000 Hz or /ga/
500 ms
* P3b

23. Auditory Late Response: Generators
P300 N2 P2 N1

24. Clinical Applications of Auditory Late Response (> 7000 Peer Reviewed Publications for “CAEP”)
Objective documentation of cortical auditory dysfunction in diverse clinical populations, e.g.,
Auditory processing, language, and reading disorders
Traumatic brain injury
Neurological and neuropsychiatric disorders
Objective assessment of hearing thresholds in suspected false or exaggerated hearing loss, especially adults seeking compensation
Documentation of benefits of intervention in infants and young children, e.g.,
Amplification
Cochlear implants

25. Clinical Applications of Auditory Late Response (Anu Sharma, PhD, University of Colorado)
Cardon G, Campbell J and Sharma A (2012). Plasticity in the developing auditory cortex: Evidence from children with sensorineural hearing loss and Auditory Neuropathy Spectrum Disorder. Journal of the America Academy of Audiology
Sharma, A, Cardon G, Henion K and Roland P (2011). Cortical maturation and behavioral outcomes in children with auditory neuropathy spectrum disorder. International Journal of Audiology,50,
Sharma, A, Nash A, and Dorman A (2009) Cortical development, plasticity and reorganization in children with cochlear implants. Journal Communication Disorders, 42, 272
Gilley PM, Sharma A, Dorman M and Martin K. (2006) Abnormalities in central auditory maturation in children with language based learning disabilities. Clinical Neurophysiology, 117, 1949

26. Clinical Applications of Auditory Late Response: Hearing Aid versus Cochlear Implant Performance (Anu Sharma, PhD, University of Colorado)

27. Clinical Applications of Auditory Late Response: Documenting Cortical Maturation (Anu Sharma, PhD, University of Colorado)

28. Clinical Applications of Auditory Late Response: Documenting Hearing Aid Performance (Anu Sharma, PhD, University of Colorado)

29. Clinical Applications of Auditory Late Response: Hearing Aid versus Cochlear Implant Performance (Anu Sharma, PhD, University of Colorado)

30. Clinical Applications of Auditory Late Response: Cochlear Implant Performance (Anu Sharma, PhD, University of Colorado)

31. Clinical Assessment of APD with the ALR: How Can We Make it Happen?
Accepted evidence-based test protocol
Clinical instrumentation with new features (ALR options), e.g.,
Multiple channels for hemisphere and eye blink electrodes
Speech stimuli available within ALR protocols
APD protocols for measurement of ALR, e.g.,
Speech-in-noise
Dichotic stimuli
Temporal processing (gap detection)
Statistical analysis of ALR parameters, e.g.,
Latency
Amplitude and amplitude under the curve
Normative data (collected with clinical instrumentation)
Maturational data on ALR
Latency and amplitude data for various stimuli

32. Auditory Event-Related Potentials to Words: Implications for Audiologists James Jerger, Jeffrey Martin & Katharine Fitzharris Plural Publishing, 2014

33. Auditory Event-Related Potentials to Words: Implications for Audiologists James Jerger, Jeffrey Martin & Katharine Fitzharris Plural Publishing, in press
Listening Task = Repeating the word that is heard

34. Thank You! Questions?
Digital Version in 2015
Pearson, 2014