An evaluation of the acoustic properties of an improved combat arms earplug

Abstract

This study investigates the performance of an improved version of the combat arms earplug (CAE). U.S. Army soldiers must operate in environments which can go from quiet to noisy in a moment. They also operate in environments where the predominant noise hazard can be either continuous or impulse noise. The current earplug of choice to address these varying protection needs is the CAE. The CAE is a two-sided earplug which provides linear attenuation for steady-state noise exposure on one side and nonlinear protection for impulse noise protection on the other. Although feedback from the field has been favorable regarding the functioning of the CAE, other concerns such as fit, comfort, size, and the need to remove, turn, and reinsert the earplug to change the modality have been raised. In order to address these concerns, the Army Research Laboratory provided funding for the development of an improved CAE. The improved CAE was evaluated for attenuation of continuous and impulse noise, soldier performance in localization and speech intelligibility tasks, and soldier acceptance on issues such as ease of use, perceived protection, equipment compatibility, sizing, and comfort. Results of these experiments will be discussed.