<Tr> <Td> </Td> <Td> Normal heart sounds Normal heart sounds as heard with a stethoscope </Td> </Tr> <Tr> <Td_colspan="2"> Problems playing this file? See media help . </Td> </Tr> <P> Heart sounds are the noises generated by the beating heart and the resultant flow of blood through it . Specifically, the sounds reflect the turbulence created when the heart valves snap shut . In cardiac auscultation, an examiner may use a stethoscope to listen for these unique and distinct sounds that provide important auditory data regarding the condition of the heart . </P> <P> In healthy adults, there are two normal heart sounds often described as a lub and a dub (or dup), that occur in sequence with each heartbeat . These are the first heart sound (S) and second heart sound (S), produced by the closing of the atrioventricular valves and semilunar valves, respectively . In addition to these normal sounds, a variety of other sounds may be present including heart murmurs, adventitious sounds, and gallop rhythms S and S . </P>

When auscultating the heart s1 sound is located at the apex of the heart and signifies