Why do heart beats sound like 2 quick beats?

Answer 1

The beats are caused by the valves in the heart closing. The first beat occurs when the ventricles contract. The pressure in them increases, so the atrioventricular valves close. The second beat occurs when the ventricles relax. As the pressure decreases, blood is sucked back from the aorta and pulmonary artery causing the semi lunar valves to close.

Answer 2

We hear the "lub" and the "dub" called S1 and S2 because of the closure of our heart valves. The S1 is produced when our Mitral and Tricuspid (M1 and T1 components) valves close when the ventricles of the heart contract, and S2 is produced then our Aortic and Pulmonary (A2 and T2 components) Valves close when the atria of the heart contracts.

Answer 3

You hear two beats (lubb-dubb). The first (lubb) coincides with closure of the mitral and tricuspid valves; the second (dubb) with closure of the aortic and pulmonary valves.