Active Acoustic and Bone Conduction Noise Cancellation for 150 dB(A) Noise Environments

There is a great need for improved hearing protection equipment with integral communication for high noise military environments such as flight lines and aircraft carrier flight decks. Deep insertion, communication earplugs (Attenuating CustomCommunication Earplug - ACCES) combined with earmuffs are the current, state-of-the-art. Through a separate Program Research and Development Announcement (NR:01-01-HE, "Active Noise Reduction Earplug System") the Air Force is soliciting approaches to addactive noise reduction capability to the ACCES earplugs to improve the low frequency noise reduction. Regardless of the reduction in acoustic pressure that can be achieved near the eardrum by any means, the factor limiting the reduction in perceivedloudness (cochlear response) is bone conduction of acoustic energy directly to the cochlea. SDL proposes an innovative study that accounts for both the acoustic and bone conduction pathway contributions to cochlear response, evaluating the feasibility ofactively attenuating the cochlear response attributable to both mechanisms. This technology has immediate commercial application to civilian industrial sectors including the airline industry, firefighters, law enforcement, search and rescue, industrialhigh pressure cleaning and sandblasting, mining and other areas.