From Ohio History Central
In 1816, Frenchman Rene Theophile Hyacinthe Lannec invented the first stethoscope. He named his invention the stethoscope by combining the Greek words stethos (chest) and skopeein (to inspect).
On December 16, 1851, Cincinnati, Ohio, doctor Nathan B. Marsh received a patent for his version of the stethoscope. Lannec's stethoscope simply consisted of a hollow wooden tube. Marsh's version, made partly from Indian rubber, was the first stethoscope to allow a doctor to utilize both ears to listen to a patient's heart. It also was the first stethoscope with a chest piece. Most modern-day stethoscopes have been modeled after Marsh's version.