Roberts's monaural stethoscope, c.1870 to 1880, English(?)
Monaural stethoscopes consist of a single hollow tube. They are different to today’s familiar Y-shaped binaural stethoscope. This monaural stethoscope is thought to be of English origin. It was used on the chest or another part of the body to listen to organs such as the heart or lungs. The round base of this stethoscope amplified sound up the tube to the ear piece.