Many different types of early stethoscopes. Catalog of instruments and medical supplies,1 869. The stethoscope is an acoustic medical device for auscultation, or listening to the internal sounds of an animal body. It is often used to listen to lung and heart sounds. It is also used to listen to intestines and blood flow in arteries and veins. The stethoscope was invented in 1816 by Ren矇 Laennec. It consisted of a wooden tube and was monaural. His device was similar to the common ear trumpet. In 1840, Golding Bird described a stethoscope he had been using with a flexible tube. Bird's stethoscope had a single earpiece. In 1851, Arthur Leared invented a binaural stethoscope, and in 1852 George Cammann perfected the design of the instrument for commercial production, which has become the standard ever since. By 1873, there were descriptions of a differential stethoscope that could connect to slightly different locations to create a slight stereo effect, though this did not become a standard tool in clinical practice.