MODELING ACTIVE OUTER HAIR CELL FUNCTION TO INVESTIGATE THE GENERATION OF DISTORTION PRODUCT OTOACOUSTIC EMISSIONS

Author

• Matthew Galipeau, University of Rhode IslandFollow

Date of Award

2026

Degree Type

Thesis

Degree Name

Master of Science in Electrical Engineering (MSEE)

Department

Electrical, Computer, and Biomedical Engineering

First Advisor

Ramdas Kumaresan

Abstract

Distortion product otoacoustic emissions (DPOAEs) are acoustic signals generated within the cochlea. Typically, DPOAEs are measured in response to a two-tone acoustic stimulus and are widely used in assessment of outer hair cell (OHC) function. Although DPOAEs have been studied extensively, the cochlear mechanisms responsible for their generation remain an active area of research. This thesis proposes a computational model based on concepts from communication theory to investigate the interactions between the basilar membrane, OHCs, stereocilia, and tectorial membrane that may contribute to DPOAE generation.

The proposed model represents the basilar membrane as a gammatone filter bank using equivalent rectangular bandwidth (ERB) spacing between channels and incorporates two methods for OHC normalization: envelope detection and coherent demodulation. Analytical derivations and model simulations were performed to examine the resulting spectral components produced by two-tone excitation of the basilar membrane. Simulated basilar membrane and OHC motion spectra were qualitatively compared with experimental measurements reported in literature.

The results demonstrate that the qualitative agreement between the simulated and measured spectra supports the feasibility of the proposed communication theory analogy and hypothesized displacement response. These findings support the proposed model as a framework for investigating DPOAE generation and measurements of cochlear motion. Future works include improved representations of OHC feedback, spontaneous otoacoustic emissions (SPOAEs), tectorial membrane motion, and operating channel shift for acoustic compression and noise-induced damage.

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 License.

Recommended Citation

Galipeau, Matthew, "MODELING ACTIVE OUTER HAIR CELL FUNCTION TO INVESTIGATE THE GENERATION OF DISTORTION PRODUCT OTOACOUSTIC EMISSIONS" (2026). Open Access Master's Theses. Paper 2752.
https://digitalcommons.uri.edu/theses/2752