Middle Ear Muscle Reflex in Normal-Hearing Individuals with Occupational Noise Exposure

Objectives: Noise-induced cochlear synaptopathy is studied extensively in animal models. The diagnosis of synaptopathy in humans is challenging and the roles of many noninvasive measures in identifying synaptopathy are being explored. The acoustic middle ear muscle reflex (MEMR) can be considered as...

Full description

Bibliographic Details
Main Authors: Sahana Vasudevamurthy, Ajith U Kumar
Format: Article
Language:English
Published: Wolters Kluwer Medknow Publications 2023-01-01
Series:Noise and Health
Subjects:
Online Access:http://www.noiseandhealth.org/article.asp?issn=1463-1741;year=2023;volume=25;issue=116;spage=1;epage=7;aulast=Vasudevamurthy
Description
Summary:Objectives: Noise-induced cochlear synaptopathy is studied extensively in animal models. The diagnosis of synaptopathy in humans is challenging and the roles of many noninvasive measures in identifying synaptopathy are being explored. The acoustic middle ear muscle reflex (MEMR) can be considered as a vital tool since noise exposure affects the low-spontaneous rate fibers that play an important role in elicitation of MEMR. The present study aimed at measuring MEMR threshold and MEMR strength. Design: The study participants were divided into two groups. All the participants had normal-hearing thresholds. The control group consisted of 25 individuals with no occupational noise exposure whereas noise exposure group had 25 individuals who were exposed to occupational noise of 85 dBA for a minimum period of 1 year. MEMR threshold and strength was assessed for pure tones (500 Hz and 1000 Hz) and broadband noise. Results: The results showed that the MEMR threshold was similar in both the groups. MEMR strength was reduced in noise exposure group compared to control group. Conclusions: The results of the study suggest that MEMR strength could be used as a sensitive measure in identifying cochlear synaptopathy with careful consideration of the stimulus characteristics.
ISSN:1463-1741
1998-4030