Back in 1816, René Laennec, a French doctor, came up with the stethoscope. It all started when he took a piece of paper and rolled it into a tube so he could hear a patient’s heartbeat without putting his ear directly on her chest. This approach, called "mediate auscultation," helped him avoid any discomfort. Besides solving this modesty issue, this simple paper tool amplified the sounds from the heart and lungs. Later on, Laennec decided to make a sturdier version out of wood.