There is an interface on Step 1 where you listen to heart murmurs. You can use the bell or the diaphragm to listen to the APTM points and left sternal border/Erb's point (and I think some other points too - maybe the carotid pulses). The interface looks very much like the one from blaufuss.org - which is an excellent website for learning the heart sounds. The question stem will usually have a hint of what the heart sound may be due to, i.e. you can use the auscultation findings to reinforce your diagnosis, but you should be comfortable with diagnosing just from auscultation.
also, all the heart sounds on my step 1 were really high quality audio, very crisp sound.