Heartbeat Sound Lub Dub -

It is so familiar that we often ignore it, yet this rhythmic double beat is one of the most complex and vital sounds in nature. But what actually creates that noise? It isn't the blood flowing, nor the heart "beating" like a drum. It is the sound of

Every healthy human heart sings the same simple, two-note song: Lub... Dub... Lub... Dub... heartbeat sound lub dub

Listen closely. That's your engine running. It is so familiar that we often ignore