For a full tutorial on proper use of a stethoscope, heart positioning and anatomy, stethoscope placement for optimal auscultation, cardiac function, heart sounds, and murmur grading please visit http://www.vetvisions.com/p411.htm

To hear the different heart sounds and murmurs, and to learn where they are typically ausculted click on the index of murmurs tab to your left. 

A brief overview of auscultation: