The objective of this project is to develop an earplug for use by helicopter crews, to be worn within the earcanal, and equipped with an active noise reduction (ANR) system, with performance for speech communication and hearing protection meeting U.S. Army safety requirements. From an analysis of the performance of earplugs with ANR, it appears that there are several approaches that could provide the required performance, provided a good air seal can be obtained between the earplug and the walls of the ear canal. A decision on which to pursue can then be made based on its performance with speech reproduction. The goal of the Phase I work is to approach the Phase II specifications in a working laboratory model of a communication earplug equipped with an ANR system. Several devices with different control structures will be constructed. The performance of each device will be compared to the target specifications, until a decision can be made on which of the alternative devices and control structures to pursue. This decision is expected to occur during the Phase I Option. The financial cost and complexity for a pair of each device will be included in the evaluation
