Reducing Background Noise Through a Stethoscope Cup Using Adaptive Filters

Utah State University

An adaptive filtering algorithm was used to test the validity of adaptively filtering respiratory signals recorded at the trachea with an external reference microphone. Two different setups were tested. The first used a microphone in open air, the second used a microphone that was housed inside a second stethoscope cup. The primary microphone was affixed to a phantom material. External sounds and music were played via aloud speaker to record additive noise data from within the stethoscope cup. Data showed that adaptive filtration using a secondary stethoscope cup was the most effective method to remove ambient noises.