Heart Sounds

Heart sounds are mainly produced when valve closures cause turbulence in the blood.

These are best heard at chest locations slightly away from the valves as the blood disperses the sound.

Auscultation is listening to the body's internal sounds using a stethoscope.

The heart produces four types of sounds, but only two are audible with a stethoscope.

The first sound, S1, or the lubb sound, is caused by the closure of the AV valves when ventricular systole starts. It is louder and longer than other heart sounds.

S2, or the dupp sound, is due to the closure of the semilunar valves at the start of ventricular diastole.

The inaudible S3 and S4 are due to blood turbulence during ventricular filling and atrial systole. 

Murmurs are abnormal heart sounds frequently observed in children and older people but can be pathological in adults.

An incompetent valve that fails to close completely is heard as a swishing sound on the stethoscope.

In contrast, a stenotic valve does not open completely, resulting in a rumbling sound.