Michael Sasha John

Dr. Michael Sasha John

Research Associate Rotman Research Institute, Baycrest

Assistant Professor, Cross-appointment Institute of Biomaterials and Biomedical Engineering, University of Toronto

Entrepreneur /Inventor

Research Focus

My research strives to shed light on how the human auditory system processes sound. This effort has resulted in clinical devices which are used to evaluate hearing in both infants and adults. By way of evaluating neurophysiological correlates of auditory processing key advances in the field of objective audiometry using auditory steady-state responses (ASSRs) have been made. My early work with Dr. Terry Picton helped form a solid foundation for what we have termed the multiple auditory steady-state response (MASTER) technique and demonstrated how the manipulation of several key parameters either improved or degraded the performance of this testing technique. The understanding obtained in these early studies, has recently enabled us to make several advances that have significantly increased the power, speed, accuracy, and comprehensiveness of the technique. Our laboratory has introduced new types of stimuli that evoke more robust responses and thereby permit a more rapid and accurate evaluation of the auditory system's capacity for detecting both frequency modulation and amplitude modulation. The responses evoked by these novel stimuli are positively correlated with an individual's speech processing abilities. The technique may serve to objectively quantify both the processing deficiencies that underlie hearing deficits, and also the efficacy of hearing aid devices in overcoming these deficits.

Publications

Title Source (Journal/Book/Conference) Authors/Presenters Published On Type
Measurement of hearing-protector attenuation using auditory steady state responses 167th Meeting of the Acoustical Society of America in Providence, Rhode Island Valentin O, John MS, Laville F 1399262400 Presentation
A Reevaluation of the Costs of Heart Failure and its Implications for Allocation of Health Resources in the United States Clinical Cardiology Voigt J, John MS, Taylor A, Reynolds M, Krucoff MW, Gibson CM 1398916800 Journal Article
ASSRs Elicited by Varying Depths of Amplitude Modulation in Young and Elderly Subjects Association for Research in Otolaryngology Dimitrijevic A, Alsamri J, John MS, Purcell D, George S, Zeng F 1393045200 Abstract
ASSR Exploration of Amplitude Depth Modulation in Young and Elderly Humans International Evoked Response Audiometry Study Group Dimitrijevic A, Alsamri J, John MS, Purcell D, George S, Zeng F 1370750400 Presentation
Recurrent MI Increases Risk of Congestive Heart Failure Society for Cardiovascular Angiography and Interventions (SCAI) Scientific Sessions Hopenfeld B, John MS, Krucoff MW 1367985600 Abstract
A Statistically Based Acute Ischemia Detection Algorithm Suitable for an Implantable Device Ann Biomed Eng Hopenfeld B, John MS, Fischell TA, Johnson SR 1354338000 Journal Article
ALERTS Quality of Life(AQOL) study: Review of Results The ALERTS Trial Principal Investigator Conference John MS 1352955600 Presentation
Magnitude and Duration of Ischemic Events Detected Using Permanent Intracardiac ST-Segment Monitoring: First In Human Experience American College of Cardiology Gibson M, Guimarães VS, John MS, Keenan D, Feitosa AM, Medeiros P, Piegas LS, Krucoff MW, Holmes D 1332648000 Presentation
Demographics of the ALERTS trial Cohort The ALERTS Trial Principal Investigator Conference John MS 1331784000 Presentation
Review of ALERTS intracardiac monitoring results to date The ALERTS Trial Principal Investigator Conference John MS 1331784000 Presentation
Optimal Detection Paradigm using Sequential Testing for Auditory Steady State Response IERASG 2011 Choi J, Purcell D, John MS 1309320000 Presentation
Phase stability of auditory steady state responses in newborn infants Ear and Hearing Choi JM, Purcell DW, John MS 1293858000 Journal Article
Intracardiac ST-Segment Monitoring in Ambulatory Patients: Variability during Normal Daily Life and Occlusion-Events Heart Rhythm Krucoff M, John MS, Holmes D, Foster M, Kovach R, Fischell T, Gibson MC 1273636800 Presentation
Initial Results Using an Implantable ST-Segment Monitoring System that Detects and Alerts Patients To Coronary Plaque Rupture and Ischemia Society for Cardiovascular Angiography and Interventions (SCAI) Gibson MC, Avezum A, John MS, Guimaraes H, Fischell T, Fischell DR, Foster M, Kovach R, Medeiros P, Piegas L, Holmes D 1273032000 Presentation
Evaluating the modulation transfer function of auditory steady state responses in the 65 Hz to 120 Hz range Ear and Hearing Purcell DW, John MS 1270440000 Journal Article
Initial clinical results using intracardiac electrogram monitoring to detect and alert patients during coronary plaque rupture and ischemia Journal of the American College of Cardiology Fischell TA, Fischell DR, Avezum A, John MS, Holmes D, Foster M, Kovach R, Medeiros P, Piegas LS, Guimaraes H, Gibson CM 1270440000 Journal Article
The Guardian: an implantable system for chronic ambulatory monitoring of acute myocardial infarction Journal of Electrocardiology Hopenfeld B, John MS, Fischell DR, Medeiros P, Guimarães HP, Piegas LS 1259730000 Journal Article
Use of ASSR Phase in Newborn Hearing Testing International Evoked response Audiomety Study Group (IERASG) Choi JM, John MS, Purcell DW 1236056400 Presentation
Multiple Auditory Steady State Responses (80-101 Hz): Effects of Ear, Gender, Handedness, Intensity and Modulation Rate Ear and Hearing Picton TW, van Roon P, John MS 1233464400 Journal Article
Technical principles of auditory steady-state response testing Auditory Steady-State Response: Generation Recording, and Clinical Applications John MS, Purcell DW 1207368000 Book Chapter
Future directions of auditory steady-state response testing Auditory Steady-State Response: Generation Recording, and Clinical Applications Rance G, John MS 1207368000 Book Chapter
Human auditory steady-state responses during sweeps of intensity Ear and Hearing Picton TW, van Roon P, John MS 1167627600 Journal Article
Simultaneous latency estimations for distortion product otoacoustic emissions and envelope following responses Journal of the Acoustical Society of America Purcell DW, van Roon P, John MS, Picton TW 1136091600 Journal Article
Human temporal auditory acuity as assessed by envelope following responses Journal of the Acoustical Society of America Purcell DW, John MS, Schneider BA, Picton TW 1101877200 Journal Article
Auditory steady-state responses and word recognition scores in normal-hearing and hearing-Impaired adults Ear and Hearing Dimitrijevic A, John MS, Picton TW 1075611600 Journal Article
Recording auditory steady-state responses in young infants Ear and Hearing John MS, Brown DK, Muir PJ, Picton TW 1072933200 Journal Article
Avoiding electromagnetic artifacts when recording auditory steady-state responses Journal of the American Academy of Audiology Picton TW, John MS 1072933200 Journal Article
Efficient stimuli for evoking auditory steady-state responses Ear and Hearing John MS, Dimitrijevic A, Picton TW 1064980800 Journal Article
Human auditory steady-state responses International Journal of Audiology Picton TW, John MS, Purcell DW, Dimitrijevic A 1054440000 Journal Article
Human auditory steady-state responses: The effects of recording technique and state of arousal Anesthesia & Analgesia Picton TW, John MS, Purcell DW, Plourde G 1041397200 Journal Article
Concurrent measurement of distortion product otoacoustic emissions and auditory steady state evoked potentials Hearing Research Purcell DW, John MS, Picton TW 1041397200 Journal Article
Auditory steady-state responses and word recognition scores in normal hearing and hearing-impaired adults XVIII IERASG BIENNIAL SYMPOSIUM Dimitrijevic A, John MS, Picton TW 1041397200 Presentation
Use of modulated noise in newborn hearing screening XVIII IERASG BIENNIAL SYMPOSIUM John MS, Brown D, Muir P, Picton TW 1041397200 Presentation
Auditory steady-state responses to exponential modulation envelopes Ear and Hearing John MS, Dimitrijevic A, Picton TW 1017637200 Journal Article
Possible roles for the auditory steady-state responses in identification, evaluation and management of hearing loss in infancy Audiology Today Picton TW, John MS, Dimitrijevic A 1009861200 Journal Article
Advantages and caveats when recording steady-state responses to multiple simultaneous stimuli Journal of the American Academy of Audiology John MS, Purcell DW, Dimitrijevic A, Picton TW 1009861200 Journal Article
Multiple auditory steady-state responses Annals of Otology, Rhinology, and Laryngology Picton TW, Dimitrijevic A, John MS 1009861200 Journal Article
Estimating the audiogram using multiple auditory steady-state responses Journal of the American Academy of Audiology Dimitrijevic A, John MS, van Roon P, Purcell DW, Adamonis J, Ostroff J, Nedzelski JM, Picton TW 1009861200 Journal Article
Possible roles for the auditory steady-state responses in fitting hearing aids A Sound Foundation Through Early Amplification Picton TW, Dimitrijevic A, van Roon P, John MS, Reed M, Finkelstein H 1009861200 Book Chapter
The use of phase in the detection of auditory steady-state responses Clinical Neurophysiology Picton TW, Dimitrijevic A, John MS, van Roon P 999316800 Journal Article
Human auditory steady-state responses to tones independently modulated in both frequency and amplitude Ear and Hearing Dimitrijevic A, John MS, van Roon P, Picton TW 986014800 Journal Article
Weighted averaging of steady-state responses Clinical Neurophysiology John MS, Dimitrijevic A, Picton TW 983422800 Journal Article
Multiple auditory steady-state responses to AM and FM stimuli Audiology & Neurotology John MS, Dimitrijevic A, van Roon P, Picton TW 978325200 Journal Article
Human auditory steady-state responses to amplitude-modulated tones: Phase and latency measurements Hearing Research John MS, Picton TW 951886800 Journal Article
MASTER: A Windows program for recording multiple auditory steady-state responses Computer Methods and Programs in Biomedicine John MS, Picton TW 949381200 Journal Article
Intracerebral sources of human auditory-evoked potentials Audiology & Neurotology Picton TW, Alain C, Woods DL, John MS, Scherg M, Valdes-Sosa P, Bosch-Bayard J, Trujillo NJ 920264400 Journal Article
Auditory steady-state responses: Using phase to measure latency SOCIETY FOR NEUROSCIENCE ABSTRACTS John MS, Picton TW, Alain C 910414800 Abstract
Multiple Auditory Steady-state Responses (MASTER): Stimulus and Recording Parameters Audiology John MS, Lins OG, Boucher B, Picton TW 888728400 Journal Article

Education

Academic Appointments

  • 2003–Present: Research Associate, Rotman Research Institute, Baycrest, Toronto, Canada
  • 2000–2003: Post-Doctoral Fellow, Rotman Research Institute, Baycrest, Toronto, Canada
  • 2007–2010: Assistant Professor, Cross-appointment, Institute of Biomaterials and Biomedical Engineering, University of Toronto

Reviewership

Consulting

Editorial Board

  • 2001–2005: Clinical Neurophysiology
  • 2003–2004: International Journal of Audiology
  • 2002–2003: Hearing Research
  • 2004–2009: Ear and Hearing Guest Section Editor

Research Projects

External

  • 2000–2003: Evoked Potential Audiometry
    Collaborators: Picton, Stapells, John

    Sponsors: CIHR, 236,082

    MT-14362
  • 2002–2003: A Screening Test for Hearing Using Auditory Steady-State Responses
    Collaborators: Picton, John, Brown

    Sponsors: CIHR, 95,094

  • 2004–2007: Steady-State Response Audiometry
    Collaborators: Stapells, John, Dimitrijevic

    Sponsors: CIHR, 354,652

    Operating Grant
  • 2005–2008: Improving Methods of Evoked Potential Audiometry
    Collaborators: John

    Sponsors: CIHR, 206,733

  • 2008–2009: Combining musical training through VMI and Smart Kids Learning Software
    Collaborators: Chau, John, Moreno

    Sponsors: ORCP Proof Of Principal Grant (Ministry of Research and Innovation), 50,000

  • 2009–2010: Pre-commercialization of the VMI Virtual Music Instrument and Smarterkids training
    Collaborators: Chau, John, Moreno

    Sponsors: NSERC/CIHR: Intellectual Property Mobilization Program, 24,000

  • 2009–2010: Acute Ischemia Monitor Utilizing Subcutaneous Electrodes
    Collaborators: Hopenfeld, John, Johnson, Fischell, Fischell, Harwood

    Sponsors: NIH Small Business Innovation Grant (SBIR), 168,483

    1R43HL96158-01
  • 2010–2012: Neurophysiological Modulation Transfer Functions of Auditory Neuropathy Patients
    Collaborators: John, Purcell, Dimitrijevic

    Sponsors: The Hearing Foundation of Canada, 22,500

  • 2011–2012: Acute Ischemia Monitor Utilizing Subcutaneous Electrodes
    Collaborators: Hopenfeld, John, Johnson, Fischell, Fischell, Harwood

    Sponsors: NIH Small Business Innovation Grant (SBIR Phase II), 1,360,345

  • 2014–2016: Acute Ischemia Monitor Utilizing Subcutaneous Electrodes
    Collaborators: Keenan, Johnson, John, Hopenfeld

    Sponsors: NIH Small Business Innovation Grant (Phase 2-competing Renewal), $2,400,000

Internal

  • 2010: Real-time protocol adjustment for auditory steady-state response tests using a modified bootstrap design
    Collaborators: Terry Picton
    Institutions: Rotman Research Institute, Toronto
  • 2010: Steady-State Response Audiometry in Neuropathy
    Collaborators: Andrew Dimitrijevic
    Institutions: Rotman Research Institute, University of California, Irvine
  • 2001–2003: Post-Doctoral Fellowship Award
    Institutions: Rotman Research Institute , 64,000

Links

Contact

The Rotman Research Institute
Baycrest
3560 Bathurst Street
Toronto, Ontario
Canada M6A 2E1 Phone: 646-644-4661 Email: sjohn@rotman-baycrest.on.ca Fax: 416-785-2862