Ajouter à votre calendrierConférencier : Brandon Paul, Ph.D.
Résumé
Recent research in humans and animals has shown that moderate noise exposure, producing only temporary threshold shifts in the audiogram, can lead to permanent damage of synapses connecting inner hair cells and auditory nerve fibers in the cochlea. This type of damage appears to be preferential for nerve fibers with high thresholds of firing while fibers with lower thresholds are less affected. As a result, synaptic losses appear to express as impairments in suprathreshold listening ability, such as detecting temporal modulations in sounds or localizing sounds in noisy environments, but not in conventional threshold testing. For this reason it has been termed « hidden » hearing loss (HHL).
A present challenge for researchers and clinicians is to identify and characterize HHL in humans. I will briefly review candidate electrophysiological measures of HHL (e.g., envelope following responses, auditory brainstem responses) based on human and animal studies. I will then present electrophysiological results from my own studies in humans suggesting that a) lifetime noise exposure history can in part predict deficits in suprathreshold sound encoding (suggestive of HHL) in young adults with normal audiograms, and b) tinnitus sufferers with normal audiograms have worse suprathreshold sound encoding compared to controls, suggesting that severe HHL can lead to tinnitus. Last I will address a few challenges behind electrophysiological approaches (such as within-subject normalization and recording parameters) that need to be addressed before these tools are useful in the clinic.
Mini Bio
Brandon Paul is currently a postdoctoral researcher in the School of Speech Therapy and Audiology supervised by Dr. Sylvie Hébert and Dr. Marc Schoenwiesner (Department of Psychology) within the International Laboratory for Brain, Music, and Sound Research (BRAMS) at the University of Montreal. He is working on developing objective physiological tests to diagnose the presence of tinnitus. He holds a Ph.D. in Psychology from McMaster University, and a M.A. in Speech in Hearing Science and B.Mus. in Music Theory from The Ohio State University.