A stethoscope is a medical device used by physicians or healthcare providers to listen to the sounds generated internally by the heart, lungs, and intestinal tract. It is also used to check blood pressure. The stethoscope was invented in 1816 by French doctor Rene Theophile Hyacinthe Laënnec as the first effective non-invasive tool. Todays stethoscopes use sound amplification and noise-canceling technology to let healthcare providers more easily hear heart and lung sounds, dampen external noise, and store data electronically. The stethoscope is an important tool for diagnosing different diseases based on what doctors hear. Doctors listen to the heart and lungs for both abnormal heart function and fluid in the lungs, and can identify abnormalities that may indicate if you need emergency attention. Some stethoscopes are equipped with EKG technology that allows doctors to view your heart rate while listening to it simultaneously. Despite recent technological developments, the traditional stethoscope is still an enduring part of practicing medicine and is considered a lifesaving tool.