No, you can buy a high quality stethoscope for 35.00. It just doesn’t come with the word “Lxxxxxx” on it.

I’ve got a couple of those Spy Ear thingamajigs I bought many years ago intending to find a parabolic dish to make a homebrew long distance listener but never got aronud to it so they’re still in their packets.
Now I need a stethoscope as well as a parabolic dish for projects I’ll never get round to finishing ;)

…made one of these a long time ago (1st year at medschool) thinking the same thing… in reality they are less practical than a stethoscope. Earphones tend to tangle up, especially when rushing between patient. The beforementioned battery aspect is valid too. Another aspect is that you need to disinfect these after each patient (otherwise you tend to transfer nosocomial diseases to your weakest patients).

also this approach may work well with some QTC (quantum tunneling composite) as the sensor, as the resistance change is fairly linear and immune to mains noise.

-A

This was my final year engineering project. Made an electronic stethoscope with a datalogger on the other end and recorded the sounds. The idea was for training, you could demonstrate the sound of an arrhythmia to a entire class of students so they knew what to look for. You could map it visually and hear the playback to help comprehension. Plus your GP could keep a record onfile so they could compare your heart patterns over your lifetime, thought you might be able to predict things eventually (with enough data). Think I got it all down to under $20AUD. Then I graduated and went into mining & resource engineering…