Seminars in Hearing Research at Purdue (SHRP)

Title: Central gain in aging, tinnitus, and temporary hearing loss

Speaker: Hari Bharadwaj, Assistant Professor of SLHS/BME

Date: March 04, 2021

Time: 10:30 – 11:20 am

Zoom Info:

https://purdue-edu.zoom.us/j/99529097922?pwd=c1d0bGdoYzhjRFZLMGM0NVJTSUxTQT09

Meeting ID: 995 2909 7922

Passcode: 240315

Abstract:

The nervous system is known to adapt in many ways to changes in the statistics of the inputs it receives. An example of such plasticity observed in animal models is that central auditory neurons tend to retain their driven firing rate outputs despite reductions in peripheral input due to hearing loss or cochlear deafferentation. The perceptual consequences of such adaptations are unknown; pathological versions of such "central gain" are thought to contribute to tinnitus and hyperacusis.  To investigate central gain in humans, we designed an electroencephalogram (EEG)-based paradigm that concurrently elicits robust separable responses from different levels of the auditory pathway. Using this measure in a cohort of middle-aged subjects with normal audiograms, we find that cortical responses are relatively invariant despite a clear monotonic decrease in auditory nerve responses with age, a result consistent with widespread age-related cochlear deafferentation and central gain. We then applied the same measures to a cohort of individuals with persistent tinnitus and to a third cohort where a week-long monaural conductive hearing loss was induced using silicone earplugs. Overall, our results suggest that central gain following reduced input is ubiquitous in humans and may have consequences for listening in complex environments.

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The working schedule is available here:

https://purdue.edu/TPAN/hearing/shrp_schedule

The titles and abstracts of the talks will be added here:

https://purdue.edu/TPAN/hearing/shrp_abstracts