Stethoscope heart-beat display

I am new to programming and am working on a project for my electronics class. I would like to use an arduino NG with a microphone placed in a stethoscope to display heart beats on an 8x8 led matrix with SPI interface. Any suggestions as to how I can get started?

You will need an amplifier on the microphone so you get a 5V signal out. You will need to know about your matrix, connecting them with SPI is not common so you will need to know what it expects. Read the data sheet.

there are 4 valves in the heart, the closure of each produces a sound. The closure of the mitral and tricuspid valves occurs nearly simultaneously in the normal heart and often sound like a single sound. The closure of the aortic and pulmonary valves occur temporally close to one another; in normal people the split varies with breathing. You may of may not be able to distinguish them from each other. You will for sure however get at least two distinct heart sounds per heart beat.

Not to mention that people can have ‘3rd’ or ‘4th’ heart sounds as well as murmurs etc.

there is a ‘Cardiac Exam Virtual Trainer’ from littmann I just found;

http://www.3m.com/healthcare/littmann/

it probably won’t make sense but it will give you an idea how complex the sounds can be. The important thing to remember is that you will at minimum need to deal with two sounds for each heart beat.