Stethoscope that is currently used is based on original artwork Laennec. The main parts of the lid on the modern stethoscope (bell), which may be open or closed by a thin membrane, and earpieces. Open lid (open bell) function to adjust / match the impedance between skin and air. Lid closed (closed bell) is really just a lid that has a diaphragm with a specific resonant frequency, usually high, and inhibits the low-frequency noises.
The stethoscope has many functions in health and is a very useful tool to have around, if you know what you’re listening, and place to place.
Perhaps there is a symbol of medicine’s most famous addition to the 
