This research is intended to develop a prototype stethoscope which will benefit medical personnel with a moderate hearing loss. Available electronic stethoscopes provide a large acoustical gain, but lack many needed features. These include the capability to attain a frequency dependent gain that will compensate for the user's specific frequency dependent hearing loss, and the capability to reduce the effects of airborne background noise. In addition to losing the ability to detect low intensity sound in a quiet environment, hearing impaired individuals lose the ability to discriminate relevant sounds from background noise. This stethoscope would address both of these problems. Parallel processing Digital Signal Processors would compensate for the hearing loss and use adaptive active noise control technology to attenuate background noise.National Heart, Lung, and Blood Institute (NHLBI)