Cammann Stethoscope

Dr. George Cammann of New York produced the first recognized usable binaural stethoscope in 1852. He was working as a physician at the Northern Dispensary in New York City. He had seen Marsh's model and also had a model of a soft metal, multiple-tubed stethoscope made by H. Landouzy in 1841, which was designed for two people to listen at the same time. And Charles J. B. Williams claims to have made a binaural stethoscope with lead tubes in 1843. Dr. Cammann did not claim to have the original idea for a binaural stethoscope, only to have developed a practical instrument that could be used in clinical practice. Interestingly, he never patented the stethoscope believing it should be freely available to physicians. The stethoscope was named Cammann's Stethoscope by the manufacturer of the original instrument, George Tiemann & Co. of New York. Cammann's model was made with ivory earpieces connected to metal tubes of German silver that were held together by a simple hinge joint, and tension was applied by way of an elastic band. Attached to these were two tubes covered by wound silk. These converged into a hollow ball designed to amplify the sound, and attached to the ball was a conical shaped bell chest piece.