A stethoscope is a medical device used 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 skin, with either one or two tubes connected to earpieces. The stethoscope helps amplify internal body sounds from the heart, lungs, and bowels. Each internal sound has a “normal” frequency range that doctors listen for. Stethoscopes are used by healthcare providers to diagnose different diseases based on what they hear. The device is also used to check blood pressure. The stethoscope was invented in 1816 by French doctor Rene Theophile Hyacinthe Laënnec. Today, stethoscopes have evolved in technology and some are equipped with EKG technology that allows doctors to view a patients heart rate while listening to it simultaneously. There are also electronic stethoscopes that amplify sound and utilize noise-canceling technology so physicians can hear internal body sounds more clearly. Stethoscopes are a symbol of healthcare professionals and are often seen or depicted around their necks.