# Signal Processing Along the Auditory Pathway:  Changes Following Noise Exposure

> **NIH VA I01** · VA LOMA LINDA HEALTHCARE SYSTEM · 2023 · —

## Abstract

Project Summary/Abstract
Sensorineural hearing loss (SNHL) in military personnel is commonly caused by noise- or blast-related
damage to the auditory periphery (cochlea) and/or the central system, which includes changes in the integrity
of the cochlear partition and cellular death along the auditory pathway. Hearing loss is often permanent, and
there exist no cures for sustained injuries. The current proposal seeks to characterize the signal processing
along the auditory pathway by establishing the structure-function relationship in both normal ears and with
various types of SNHL. The overall goal is to improve the diagnosis of SNHL within the clinic by separating
contributions from cochlear (sensory) and retro-cochlear (neural) loss. We will combine a novel, state-of-the-art
measurement technique (optical coherence tomography, OCT) with recordings that are already available in the
clinic [i.e., distortion product otoacoustic emissions (DPOAE) in the ear canal and frequency-following
responses (FFR) from the cortex] so that the cochlear mechanics and the detrimental effects of noise- or blast-
exposure can be evaluated at different stages along the auditory pathway. As of now, OCT measures from the
cochlea cannot be recorded from humans, but we expect that the combination of DPOAE and FFR provides a
differential diagnosis of SNHL that distinguishes damage of the sensory versus neural component. Aim 1 of
this proposal will form the foundation of the study by determining how DPOAEs and FFRs relate to cochlear
micromechanics in normal gerbil ears. The experimental results will be used to develop a Best Approximation
Model (BAM) that will predict cochlear function using DPOAEs and FFRs. In Aim 2 we will explore how various
forms of SNHL change the underlying cochlear mechanics with the specific design to differentially diagnose
sensory and neural hearing loss and establish how these changes can be quantified using a combination of
DPOAE and FFR measurements. These results will further validate the BAM developed under Aim 1. In Aim 3
we will apply the knowledge obtained in animals to humans that suffer from different types of SNHL to improve
the clinical differential diagnosis of an SNHL using DPOAEs, FFRs, and the BAM. Using direct and
simultaneous measurements along the auditory pathway, the signal processing under these conditions will be
quantified in detail. The proposed research will advance our understanding of sound processing within the
auditory system, especially at low frequencies that are important for speech and provide critical information to
improve our ability to diagnose and develop new treatments for SNHL. This will benefit our Veterans, many of
whom suffer from noise/blast-induced hearing loss.

## Key facts

- **NIH application ID:** 10536262
- **Project number:** 1I01RX003491-01A2
- **Recipient organization:** VA LOMA LINDA HEALTHCARE SYSTEM
- **Principal Investigator:** Wei Dong
- **Activity code:** I01 (R01, R21, SBIR, etc.)
- **Funding institute:** VA
- **Fiscal year:** 2023
- **Award amount:** —
- **Award type:** 1
- **Project period:** 2023-01-01 → 2026-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10536262

## Citation

> US National Institutes of Health, RePORTER application 10536262, Signal Processing Along the Auditory Pathway:  Changes Following Noise Exposure (1I01RX003491-01A2). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10536262. Licensed CC0.

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