Spectral Analysis of Heart Murmurs in Children by Goertzel Algorithm

Time and frequency review of acoustic heart signals in children is given in this paper. The following sound recordings were compared: Still’s innocent heart murmur (Still), pathologic murmur of the congenital ventricular septal defect (VSD) and the recording without the murmur (Normal). Goertzel algorithm was used, for the first time, to determine the spectral energy of the heart signals. The aim of this study is to show that this algorithm is very suitable to analyze the heart sound signals as well as suitable for heart murmurs recognition. Still’s murmur is analyzed in more detail because it is incorrectly diagnosed by many doctors. Analysis of Still’s murmur shows that it is, actually, a realistic musical tone of low frequency similar to glissando tone played on a bass guitar.