Does Combat Hearing Preservation Equipment Affect Balance?

Abstract

Objective: 1) To investigate whether the occlusion effect produced by Department of Defense (DoD) Combat Arms Ear Plugs (CAEP) affects balance. 2) To investigate whether the noise-canceling Nacre QuietPro system affects balance.

Method: Prospective study conducted from June to August 2010. Twenty subjects with normal hearing and balance function were tested with blackened goggles in 3 conditions—no hearing protection, CAEP, and with the Nacre QuietPro.

Results: An AMTI Forceplate was used to measure the 20 individuals’ average angular acceleration during a period of 20 seconds. The order of the conditions given was randomized for each individual. The mean angular acceleration for no hearing protection, CAEP, and the Nacre QuietPro conditions were 0.65, 0.69, and 0.70, respectively (1-way ANOVA, P = .706), showing a nonsignificant trend between the unprotected and protected conditions.

Conclusion: The components of an intact balance system include a variety of neural inputs, to include visual, auditory, and proprioceptive cues. Both the CAEP and Nacre QuietPro are combat hearing preservation devices currently deployed by the DoD in Afghanistan. Our pilot data show no decrement in balance with their utilization.