# Eardrum function in live and cadaveric ears: Research and clinical relevance

> **NIH NIH R01** · MASSACHUSETTS EYE AND EAR INFIRMARY · 2021 · $408,421

## Abstract

ABSTRACT:
 Chronic conductive hearing loss due to middle-ear diseases can lead to cochlear neuropathy. While our
diagnosis and management of middle-ear diseases are not perfect, in part due to incomplete knowledge of the
eardrum function for sound transmission. Multiple contradictory theories of eardrum function have been
proposed in the past 150 years. These theories are based on incomplete descriptions and misinterpretation of
existing eardrum characterizations. Almost all previous measurements of the eardrum response to sound have
used steady-state tonal stimuli, while environmental sounds, such as music, noises and speech, are transient
in nature. Little is known about the eardrum transient response in the real world. Incomplete knowledge of the
eardrum also limits our views on how to repair the diseased ear. Our first goal in this study is to provide
evidence to distinguish between these different theories of the eardrum function. Our second goal is to improve
our knowledge of the eardrum response to transient sound. Our third goal is to explore clinical application of
the measurement of the eardrum transient response for differential diagnosis of middle-ear diseases. To
achieve these goals, we propose three aims in this study. Aim 1 employs a state-of-the-art High Speed
Holographic Interferometry System (HSHIS) developed in our laboratory to quantify the eardrum transient
responses to acoustic and mechanical transient stimuli, at a very high spatial (>100,000 points) and temporal
(>100k frames per second) resolution. ‘Experimental modal analysis’ will be applied to extract three important
yet poorly quantified characteristics of the eardrum: (1) natural frequencies; (2) the magnitude and spatial
pattern of modal responses; (3) damping. Results in aim 1 will enable us to understand and describe eardrum
function with a level of sophistication that has not been available, and resolve contradictory theories of eardrum
function. Aim 2 will quantify the eardrum transient response in cadaveric human ears with simulated middle-ear
diseases. Results in aim 2 will evaluate eardrum function in pathological ears, and assess the use of our
techniques as an objective tool for differential diagnosis of middle-ear diseases. Aim 3 will study the eardrum
function in live chinchilla ears in normal and diseased middle ear conditions, such as Otitis Media with Effusion.
Very little detailed surface motion of the live eardrum has been reported in the literature, results in aim 3 will fill
in that gap. Measurements will be repeated just after euthanasia to directly quantify any post-mortem changes
in eardrum function. This aim also serves as a pilot study to evaluate the clinical utility of our system before
clinical trials in patients.

## Key facts

- **NIH application ID:** 10089435
- **Project number:** 5R01DC016079-05
- **Recipient organization:** MASSACHUSETTS EYE AND EAR INFIRMARY
- **Principal Investigator:** Jeffrey Tao Cheng
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $408,421
- **Award type:** 5
- **Project period:** 2017-02-08 → 2022-03-14

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10089435

## Citation

> US National Institutes of Health, RePORTER application 10089435, Eardrum function in live and cadaveric ears: Research and clinical relevance (5R01DC016079-05). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10089435. Licensed CC0.

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