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Seminars in Hearing Research (02/17/22) - Francois Deloche

Seminars in Hearing Research (02/17/22) - Francois Deloche

Author: M. Heinz
Event Date: February 17, 2022
Hosted By: Hari Bharadwaj
Time: 1030-1120
Location: LYLE 1150
Contact Name: Bharadwaj, Hari M
Contact Email:
Open To: All
Priority: No
School or Program: Biomedical Engineering
College Calendar: Show
Francois Deloche (Postdoctoral Associate, Department of Speech, Language, and Hearing Sciences) will present "Estimation of cochlear frequency tuning using forward-masked Compound Action Potentials" at our next Seminars in Hearing Research at Purdue (SHRP) on February 17th at 1030-1120 in LYLE 1150.

Seminars in Hearing Research at Purdue (SHRP)

Date: Thursday, February 17,  2022

Time: 10:30 – 11:20 am

Location: LYLE 1150


Speaker: François Deloche, Postdoctoral Associate, SLHS (Heinz Lab)


Title: Estimation of cochlear frequency tuning using forward-masked Compound Action Potentials


Abstract: Frequency selectivity is a fundamental property of the peripheral auditory system; however, the invasiveness of auditory nerve (AN) experiments limits its study in the human ear. Compound Action Potentials (CAPs) associated with forward-masking have been suggested as an alternative means to assess cochlear frequency tuning . Previous methods relied on an empirical comparison of AN and CAP tuning curves in animal models, arguably not taking full advantage of forward-masked CAPs to provide an accurate estimate of frequency selectivity.


I presented at the midwinter ARO meeting a new method that seeks to directly estimate the quality factor characterizing AN frequency tuning using forward-masked CAPs, without the need for an empirical correction factor. In this talk, I will return to the presentation of the newly developed model, provide further details on the estimation procedure and discuss about possible future developments.


The technique we propose is built on the long-standing convolution model of the CAP but considers the effect of masking that highlights contributions originating from different cochlear regions. The model produces masking patterns that, once convolved by a unitary response, predict forward-masked CAP waveforms. Model parameters, including those characterizing frequency selectivity, are fine-tuned by minimizing waveform prediction errors across many different masking conditions, yielding robust estimates. The method was applied to click-evoked CAPs at the round window of anesthetized chinchillas. We found a close match between our estimates of frequency selectivity and those derived from AN fiber tuning curves. Beyond this result, the model was able to predict CAP waveform differences when the probe is masked with more than 90% of the variance explained.

Funded by: Fondation Pour l'Audition (FPA)

Zoom Info:

Meeting ID: 931 0815 8900
Passcode: 11501150




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