Heart sounds in the context of Fourth heart sound

The stethoscope, from Ancient Greek στῆθος (stêthos), meaning "breast", and σκοπέω (skopéō), meaning "to look", is a medical device for auscultation, or listening to internal sounds of an animal or human body. It typically has a small disc-shaped resonator that is placed against the naked skin, with either one or two tubes connected to two earpieces. A stethoscope can be used to listen to the sounds made by the heart, lungs or intestines, as well as blood flow in arteries and veins. In combination with a manual sphygmomanometer, it is commonly used when measuring blood pressure. It was invented in 1816 by René Laennec and the binaural version by Arthur Leared in 1851.

A stethoscope that intensifies auscultatory sounds is called a phonendoscope.

Auscultation (based on the Latin verb auscultare "to listen") is listening to the internal sounds of the body, usually using a stethoscope. Auscultation is performed for the purposes of examining the circulatory and respiratory systems (heart and breath sounds), as well as the alimentary canal.

The term was introduced by René Laennec. The act of listening to body sounds for diagnostic purposes has its origin further back in history, possibly as early as Ancient Egypt. Auscultation and palpation go together in physical examination and are alike in that both have ancient roots, both require skill, and both are still important today. Laënnec's contributions were refining the procedure, linking sounds with specific pathological changes in the chest, and inventing a suitable instrument (the stethoscope) to mediate between the patient's body and the clinician's ear.