Mostly seen hanging on the doctor’s neck when ‘visiting’ the hospital or a medical clinic, but also used by every student that studies medicine, the stethoscope is perhaps the most common item associated with the medical profession, along with the white robe. It is primarily used for auscultation, which is listening to the internal sounds of the body, like heartbeats, but there are also engineering stethoscopes which are used for listening to internal sounds of various machines and other small-scale acoustic monitoring processes.
This electronic stethoscope is a very simple project with only a few parts needed. The idea is taking a broken ordinary stethoscope and modify it to have an electronic one. This project uses the Spy Ear iSpy-007 Sound Amplifier, a fun little gadget that costs $2.60 and is available for purchase at DealExtreme.com. This is basically a 3 transistor amplifier with a microphone which gets attached to a short plastic tubing using heat-shrink tubing. The amplifier must be opened to have the stethoscope diaphragm attached to the microphone in a firm and secure manner, but once this is done the electronic stethoscope is complete. You just need an earphone and you’re ready to go.
A fun and quite simple project, this electronic stethoscope has a few advantages over an ordinary one because it possesses volume control. Also, it can be connected to a speaker and/or a PC, so more than one person is able to hear through it. Lastly, it’s easy to pack and carry around because the earphone is detachable.