Active Quiet Pillow

In this project we propose to develop, test and demonstrate the potential of an Active Quiet Pillow for reducing interior noise in helicopter medical evacuation scenarios using numerical simulation and experimental testing. The potential of the Pillow design is expected to reduce the interior noise of a Blackhawk MEDEVAC helicopter from 106dB pink noise incident sound down to 90dBA at the patient"s ear. The innovation is based on a strategic combination of active and passive treatment elements in a pillow arrangement located under the patient"s head. In Phase I, numerical finite element models of the Active Quiet Pillow in a helicopter cabin interior will be developed including a modeled active noise system and passive noise treatment. The analysis will incorporate acoustic lining modeled by a surface impedance and the active speakers as baffled pistons embedded in the quiet pillow structure. The effect of the acoustic pillow liner on reducing the mid and high frequencies at the patient"s ears will be studied. Experimental verification of the noise reduction active cancellation will also be demonstrated in laboratory testing. The results will then be used to identify the key elements required for airworthiness testing for use in US Army MEDEVAC and CASEVAC operations.