Laënnec, René Théophile Hyacinthe (1781–1826)

French physician, inventor of the stethoscope in 1816. He advanced the diagnostic technique of auscultation (listening to the internal organs) with his book Traité de l'auscultation médiaté in 1819, which quickly became a medical classic.

Laënnec's special interest was in chest disease. Listening to the internal organs (auscultation) had been used diagnostically since the time of Hippocrates, but Laënnec introduced a wooden tube to transmit sound. He called it a stethoscope from the Greek stethos ‘chest’.

Laënnec was born in Quimper, Brittany. As a teenager he worked in hospitals during the French Revolution; later he studied medicine at the Ecole Pratique in Paris. He was appointed personal physician to Cardinal Fesch, uncle of Napoleon I. In 1812–13, with France at war, Laënnec took charge of the wards in the Salpetrière Hospital reserved for Breton soldiers. On the restoration of the monarchy, he became physician to the Necker Hospital, retiring in 1818. In 1822 he was appointed professor at the Collège de France.