Citation

Gan RZ, Leckness K, Smith K, Ji XD. Mil. Med. 2019; 184(Suppl 1): 251-260.

Affiliation

School of Aerospace and Mechanical Engineering, University of Oklahoma, 865 Asp Avenue, Norman, OK.

Copyright

(Copyright © 2019, Association of Military Surgeons of the United States)

DOI

10.1093/milmed/usy299

PMID

30901470

Abstract

Hearing damage induced by blast exposure is a common injury in military personnel involved in most operation activities. Personal hearing protection devices such as earplugs come as a standard issue for Service members; however, it is not clear how to accurately evaluate the protection mechanisms of different hearing protection devices for blast overpressures (BOP). This paper reports a recent study on characterization of earplugs' protective function to BOP using human cadaver ears and 3D finite element (FE) model of the human ear. The cadaver ear mounted with pressure sensors near the eardrum (P1) and inside the middle ear (P2) and with an earplug inserted was exposed to BOP in the blast test chamber. P1, P2, and BOP at the ear canal entrance (P0) were simultaneously recorded. The measured P0 waveform was then applied at the ear canal entrance in the FE model and the P1 and P2 pressures were derived from the model. Both experiments and FE modeling resulted in the P1 reduction which represents the effective protection function of the earplug. Different earplugs showed variations in pressure waveforms transmitted to the eardrum, which determine the protection level of earplugs.

© Association of Military Surgeons of the United States 2019. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Language: en

Keywords

blast exposure; finite element model; hearing protection device; human ear