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

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

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

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, 344-351 (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

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

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

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, 1210-1211. 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, 763-777.

Auditory Middle Latency Response (AMLR): Analysis Pa (22 - 30 ms) Pb 1 mV Na Amplitude (mV) Nb PAM PAM = Post-auricular muscle 100 ms

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)

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

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

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 0.55 0.20 0.35 (SD) (0.20) (0.14) (0.24) Intact Side Mean 0.86 0.28 0.63 SD (0.21) (0. 15) (0.27)

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, 405-412 155 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

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

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

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, 777-785 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

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, 777-785 Auditory training protocol Frequency discrimination training Intensity discrimination training Temporal (duration) discrimination training Dichotic Inter-aural Intensity Difference (DIID

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, 777-785 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

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

“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, 500-514

Auditory Late Response (Cortical) 5mV P2 (180 – 200 ms) P1 (50 ms) Amplitude (mV) N2 (200 - 400 ms) N1 (90 - 150 ms) 600 ms Stimulus

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

Auditory Late Response: Generators P300 N2 P2 N1

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

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, 98-106 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

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

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

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

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

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

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

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

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

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