Cardiologists refer to the two distinct sounds of the heartbeat as and S2 . Each corresponds to a different phase of the cardiac cycle.
When these valves snap shut to prevent backflow, they create turbulence in the blood. It is this snapping shut and the resulting turbulence that we hear as the heartbeat. what causes the lub dub sound of your heartbeat
It’s important to understand what you are not hearing. The powerful contraction of the heart muscle itself is virtually silent. The rush of blood filling the chambers is also silent. The lub-dub is purely the sound of , not opening. Cardiologists refer to the two distinct sounds of