Spectral and SNR improvement analysis of normal and abnormal heart sound signals using different windows

Abstract The primary function of a coronary care unit is to monitor the rhythm of cardiac patients. The cardiac abnormality of the patients should be identified during the early stage. The heart sound recoding is the phonocardiogram (PCG) signal. Stethoscopes are commonly used to hear the heart sound for diagnosis. In common, the heart murmurs can be caused by a high blood pressure, heart attack, pregnancy, rheumatic fever, anemia or thyrotoxicosis. This study analyzes PCG signals spectrally with different windows with signal-to-noise ratio (SNR) computations. The two PCG signals of normal and abnormal subjects in each were analyzed in this study. The normal subject produce clear “lub” and “dub” sounds where the abnormal subject produce a kind of whistling or swishing sound in middle which may be due to the problem of septal defect in a heart. The spectral leakage reduction by different windows helps to increase the SNR value. Simulation results of SNR with different windows are obtained using Matlab R2016b tool.