what is responsible for the sound of the heartbeat
Heart Sounds. Heart sounds are generated by the turbulance created by blood flowing through the heart, specifically when the heart valves close. Normal heart sounds can be characterized by a lub dub that occurs with a heart beat. The first heart sound (lub) occurs when the atrioventricular (AV) valves close and the second heart sound (dub) is heard when the semilunar valves close.