ASA 124th Meeting New Orleans 1992 October

4aSA10. An active noise control stethoscope.

T. R. Harley

Natl. Ctr. for Phys. Acoust., Univ. of Mississippi, University, MS 38677

A prototype of an active noise control stethoscope has been developed. The device enables medical personnel to clearly hear sound from a stethoscope device while working in a noisy environment. Using a conventional stethoscope to detect lung noises and blood pressure is difficult in many emergency medical environments, such as helicopters. An electronic stethoscope device is to be designed that will make use of digital signal processing technology to remove unwanted noise. Acoustical noise and vibrations that are detected by the stethoscope are digitally subtracted out of the stethoscope signal. The stethoscope signal is then amplified and broadcast into the earcup of an an antinoise headset. Unwanted noise penetrating the shell of the earcup is eliminated by broadcasting counteracting ``antinoise'' in addition to the amplified stethoscope signal.