René Laennec

Laennec invented the stethoscope in 1816 at the Necker Hospital in Paris when he was reluctant to press his ear directly against a young woman's chest for auscultation, as was the custom. He recalled seeing children tap a wooden beam and listen with their ear at the other end, which inspired him to roll a tightly bound cylinder of paper to transmit the sounds.

Laennec termed the technique 'mediate auscultation'—listening to internal body sounds through an intermediary instrument—as distinct from 'immediate auscultation,' which involved placing the ear directly on the patient. The word stethoscope itself comes from the Greek words *stethos* (chest) and *skopein* (to examine).

Laennec published *De l'Auscultation Médiate* in 1819, a two-volume work that systematically correlated sounds heard through the stethoscope with specific diseases and postmortem findings. He coined terms still used today, including rales, rhonchi, bronchophony, and pectoriloquy, and described the pathology of cirrhosis and tuberculosis.

Laennec died in 1826 at the age of 45, reportedly from tuberculosis—a disease he had studied and described extensively in his clinical work. Some later medical historians have suggested he may have had lymphoma, but tuberculosis remains the most widely accepted cause of death.