Tim Miller, age 12, of Larchwood, Iowa, for his question:
HOW DOES A STETHOSCOPE WORK?
A stethoscope is a device doctors use to hear the sounds produced by certain organs of the body, such as the heart, lungs, intestines, veins and arteries. The stethoscope picks up the sounds made by these organs and excludes other sounds.
A stethoscope has a body contact piece, which is placed against the body of the patient, and earpieces; which are placed in the ears of the doctor. A hollow rubber tubing connects the body contact piece to the earpieces.
Doctors use either a bell, diaphragm, or bell diaphragm combination body contact piece. The bell type picks up low sounds while the other picks up higher sounds.
The first stethoscope was made in 1816 from a hollow wooden tube by a French doctor named Rene Laennec.