how does a stethoscope work?

HappyTo BeHereTo answered

Or you can look here:

http://science.howstuffworks.com/innovation/everyday-innovations/stethoscopes.htm

Broad Kenny answered

It transmits the sound from the chest piece, via air-filled hollow tubes, to the listener's ears. The chest piece usually consists of two sides that can be placed against the patient for sensing sound; a diaphragm or bell.

Tom Jackson answered

There was a segment on a cable TV show about the invention of the stethoscope.

This is from wikipedia; you might enjoy the rest of the article.

The stethoscope was invented in France in 1816 by René Laennec at the Necker-Enfants Malades Hospital in Paris.^[1] It consisted of a wooden tube and was monaural. Laennec invented the stethoscope because he was uncomfortable placing his ear on women's chests to hear heart sounds.^[2]

en.wikipedia.org/wiki/Stethoscope