An Active Noise Reduction Communication Earplug for Helicopter Crew

Army SBIR Topic A04-199 identifies the need for an Active Noise Reduction (ANR) Communication Earplug for Helicopter Crew that, when used in combination with a Gentex HGU-56 helmet, provides “effective attenuation of at least 40 dB at all frequencies, with adequate speech intelligibility, while meeting safety requirements with respect to potential injuries caused by side impacts.” Phase I research has demonstrated total (active+passive) noise reduction of 41-42 dB for sum-of-tones 80-1250 Hz and 25-50 dB for UH-60 cockpit noise 80-2500 Hz using an ANR modified Communication Earplug (CEP) and a hybrid feedforward-feedback ANR algorithm. Phase II research will further develop and evaluate an ANR earplug and associated digital signal processing (DSP) module through systems engineering with integrated cycles of electro-acoustic and mechanical design of the earplug, ANR and communications performance evaluation, and design refinement. Manikin testing, human subject evaluation, field performance, speech intelligibility evaluation, and human factors assessment are primary components of Phase II design and evaluation protocols. A complete design of a product-ready earplug, capable of ANR and communication feedthrough, and an ANR DSP module will be developed. Sound Innovations will deliver 6-10 ANR systems comprised of the ANR earplugs and DSP modules to the U.S. Army and will pursue commercialization for military and civilian markets through Phase III and private funding.