Medicolozy - There are two normal heart sounds that occur in sequence with each heart beat. These are the first heart sound (S1) and second heart sound (S2), produced by the closing
![File:Phonocardiograms from normal and abnormal heart sounds with pressure diagrams with location on the precordium.png - Wikimedia Commons File:Phonocardiograms from normal and abnormal heart sounds with pressure diagrams with location on the precordium.png - Wikimedia Commons](https://upload.wikimedia.org/wikipedia/commons/thumb/7/73/Phonocardiograms_from_normal_and_abnormal_heart_sounds_with_pressure_diagrams_with_location_on_the_precordium.png/1200px-Phonocardiograms_from_normal_and_abnormal_heart_sounds_with_pressure_diagrams_with_location_on_the_precordium.png)
File:Phonocardiograms from normal and abnormal heart sounds with pressure diagrams with location on the precordium.png - Wikimedia Commons
![Phonocardiograms from normal and abnormal heart sounds. Adapted from... | Download Scientific Diagram Phonocardiograms from normal and abnormal heart sounds. Adapted from... | Download Scientific Diagram](https://www.researchgate.net/profile/Ricardo-Cruz-Correia/publication/309327433/figure/fig1/AS:546171858808832@1507228926746/Phonocardiograms-from-normal-and-abnormal-heart-sounds-Adapted-from-netterimagescom.png)