Hearing Protection System for Extreme Noise Environments

Creare and Dartmouth College propose to design, fabricate, and test a safe and effective system for hearing protection in very high noise level environments. Current Air Force ground crews are forced to work in close proximity to aircraft engines thatproduce in excess of 150 dB of noise, which can result in noise-induced hearing loss after brief exposures without sufficient hearing protection. The harmful effects of noise at such extreme levels is manifest through both air- and bone-conducted noise.These flight and ground crews also have a need to communicate with other personnel. However, no existing hearing protection system offers the right level of noise reduction for these crews to work safely in extreme noise environments. Our extreme noisereduction system is based on combined passive and active noise reduction technologies and will mitigate the contribution of both air- and bone-conducted noise on the inner ear. During the Phase I project, we will use an innovative technique to quantifythe contribution of air- and bone-conducted noise to the inner ear and develop an extreme noise reduction system based on the data. During the Phase II project, we will fabricate and test a prototype extreme noise reduction system.The Creare extreme noise reduction (ENR) system will reduce the harmful effects of long duration exposure to extremely high noise levels and will facilitate speech intelligibility. The ENR system will be used by tank crews, flight crews, flight deckpersonnel, mechanized infantry, and commercial operators of noisy equipment.