# Auditory Processing Deficits in Early-Onset Conductive Hearing Loss

> **NIH NIH R01** · NORTHEAST OHIO MEDICAL UNIVERSITY · 2020 · $458,567

## Abstract

PROJECT SUMMARY
Early conductive hearing loss (eCHL) in children, arising from chronic ear infections, can induce long-lasting
problems in auditory perception and language processing. When raised with environmental challenges, such
as disrupted attachment and low socio-economic status, these children are at greater risk for long-term
language deficits. One explanation is that early-life stress (ELS) and eCHL in conjunction could interact in the
nervous system to produce compounded deficits in auditory perception. While ELS has well-known effects on
higher neural regions involved in attention and learning, our evidence suggests a novel auditory effect for ELS:
altering sound-evoked responses in the auditory cortex (ACx). This would degrade the fidelity of sensory
representations available to higher regions affected by ELS, and could contribute to known cognitive problems
with ELS. Such sensory degradation would compound the auditory perceptual issues arising from eCHL.
The central hypothesis of this proposal is that ELS causes deficits in auditory perception, and worsens eCHL-
induced deficits, by altering sensory representations in the central auditory system. We will measure effects of
ELS on auditory perception and ACx sensitivity, and will determine whether altered inhibition in the auditory
system contributes to measured deficits. Amplitude modulations (AM) in sounds will be used to determine
perceptual and neural auditory sensitivity, because AMs are intrinsic to speech and animal vocalizations, and
their accurate perception involves ACx. In Aim 1, we test whether ELS impairs auditory perception and
compounds impairments from eCHL. Animals will be trained to detect AM sounds with varying parameters
(modulation rate and depth). This will characterize the nature of the deficits by identifying AM parameters that
are challenging for animals to detect when raised with ELS, eCHL, or both. In Aim 2, we test whether
perceptual deficits arising from ELS and ELS+eCHL involve impaired sensory encoding in ACx. Neural
responses while animals listen passively to AM sounds will indicate altered sensory representations. Task
performance is known to increase ACx sensitivity by engaging additional non-sensory areas, including
cognitive regions known to be altered by ELS. We will determine whether ELS impairs non-sensory
contributions to auditory processing, by comparing ACx responses while animals are learning and performing
the task versus listening passively to the same sounds. In Aim 3, we will determine if ELS and ELS+eCHL alter
inhibition in ACx and other subcortical auditory regions, and whether inhibitory rescue improves ACx function
and perception. This will identify mechanistic changes underlying ELS-eCHL effects. Together, these
experiments will reveal the extent to which early-life stress impairs auditory processing via changing sensory
and non-sensory regions. This will broaden our understanding of experiences that interact with hearing loss,
and ...

## Key facts

- **NIH application ID:** 9972208
- **Project number:** 2R01DC013314-06A1
- **Recipient organization:** NORTHEAST OHIO MEDICAL UNIVERSITY
- **Principal Investigator:** Merri J. Rosen
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $458,567
- **Award type:** 2
- **Project period:** 2014-04-01 → 2025-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9972208

## Citation

> US National Institutes of Health, RePORTER application 9972208, Auditory Processing Deficits in Early-Onset Conductive Hearing Loss (2R01DC013314-06A1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9972208. Licensed CC0.

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