Stethoscopes are acoustic medical devices for listening to the internal sounds of a human or animal body. A stethoscope is often used to listen to the heart and lungs; it can also used to listen to veins, arteries, blood flow, and intestines. When used with a sphygmomanometer, it is often used for measuring blood pressure.
A stethoscope consists of 3 basic pieces: the headset (this includes ear tips and an ear tube), tubing (which connects the headset to the chest piece), and a chest piece. The chest piece has a tunable diaphragm and an open bell, a stem which connects the chest piece to the tubing. The diaphragm picks up high-pitched noises and once it's placed on the body diaphragm waves and vibration travel through the tubing. The open bell oscillates low pitch sounds (such as heart tones) and has acoustic waves travel up the same way as the diaphragm waves traveled.
The stethoscope works by the physician putting the ear pieces or ear tips into their ears. The user then applies the chest piece to the area of the patient under examination. The sound is carried from the chest piece through the tubing to the headset into the user's ears.
There are two different kinds of stethoscopes: acoustic and electronic.
Acoustic stethoscopes are more frequently used. Fetal stethoscopes are a common type of acoustic stethoscopes
Electronic stethoscopes are less common and not used on a daily basis in the medical field. Doppler stethoscopes are a type of electronic stethoscopes. Features of an electronic stethoscope include noise reduction, adjustable amplification and digital.