This is going to be a long post, but oh well.
You can google 'heart sounds' and find plenty of websites that offer audio clips of heart sounds. Listen to these sounds repeatedly. Do NOT try to memorize what the sounds sound like; rather, just identify the *patterns*. Identify S1 and S2 for every audio clip, identify systole and diastole, listen for the presence or absence of extra murmur sounds (honestly, you probably do not need to concern yourself with whether or not a murmur is 'blowing' or crescendo-decrescendo if you can identify the valve involved and systole vs diastole, at least for the purposes of step 1). You may be asking, how do I identify all these things?? Read on.
Heart sound basics:
1. Identify S1 and S2.
A big clue as to which is which is the fact that diastole is longer than systole. Tap your fingers out to the heart rhythm along with S1 and S2 (I find this to be helpful when there are other sounds like gallops or clicks or opening snaps, which can sometimes confuse you into thinking they are S1 or S2). When you tap your fingers along with S1 and S2, you'll be able to tell if the extra gallop/click/snaps are occurring in diastole vs systole depending on when the extra sounds occur in relation to your taps.
-More advanced: If you can't tell which sounds are S1 and S2 based on the length of systole and diastole, revert to the first rule of heart sounds. First rule of heart sounds = heart sounds are loudest closest to where they originate. S1 will be louder at the apex (bottom) of the heart because this sound is created by the closure of the mitral and tricuspid valves, which are 'closer' to the bottom of the heart. S2 will be louder at the base (top) of the heart because it is created by the closure of the aortic and pulmonic valves, which are closer to the top of the heart. You can use this topology to help you identify S1 and S2. For example, put your virtual stethoscope near the top of the heart. The louder of the two beats is S2, and the softer one (which you may not even be able to hear) is S1. The opposite is true for the apex/bottom of the heart.
2. Stick it to the man
Even if you can't tell what is S1 and S2 from all that hard work in step 1, you can still easily figure out if the heart murmur is occurring in systole or diastole on the exam because they give you a way to cheat. The virtual patient has a very visible carotid pulse. If you hear the murmur while you see the carotid bulging, you know it is systolic. If the murmur occurs while the carotid is flat, it's a diastolic murmur. This essentially renders all of the advice given in #1 as useless for the purposes of step 1, but alas, I had already written it up...so...yeah.
3. What valve is involved?
This brings me to my second made-up rule of heart sounds: topology is key. Memorize the **** out of the APTM mnemonic for remembering where the heart valves are located in the chest. It doesn't matter if you memorize what murmurs go with the valves' locations; you can figure this out if you don't memorize it. But you should damn well know that most sounds over the aortic valve are heard best in the 2nd intercostal space on the right sternal border. You can memorize 4 location facts. I just know you can.
Combine this with first rule of heart sounds! Murmurs coming from the tricuspid or mitral valves are heard best at the apex (bottom) of the heart, and thus are loudest in the 4th and 5th intercostal spaces.
Murmurs coming from the aortic and pulmonic valves are heard best at the base (top) of the heart, and are thus loudest in the 2nd intercostal spaces on the left and right, respectively.
On the exam, if you can figure out if the heart sound is in systole or diastole, and then figure out which valve is generating the sound, you essentially have solved the puzzle. A diastolic murmur that is loudest in the mitral valve area? That must be mitral stenosis! 10 points to Gryffindor!
(Extra credit). Extra sounds: S3 and S4 are the big ones. These will always be heard best at the apex/bottom of the heart. They say these sounds when combined with S1 and S2 are like the rhythm of "Kentucky" (S4) or "Tennessee" (S3) but this relies on you saying the names of these great states in an unnatural way. If you've identified S1 and S2 by now, just figure out which one your extra sound is closer to. S4 comes just before S1, while S3 comes just after S2.
I think there is quite enough information to be getting on with in this post, so I'll stop. If you have more specific questions about identifying a particular heart sound, I'd love to try to confuse you more with my unnecessarily long explanations of how I understand these sounds.
