Who invented Stethoscope?

Rene Laennec, 1816

The name ‘stethoscope’ comes from Greek words meaning ‘looking at the chest’, but the organs of ‘looking’ in this case are the ears. The name was given by its inventor, French doctor Rene Laennec. Various myths surround the discovery: that Laennec could not hear a patient’s heart because street urchins were making a racket outside, and/or that the urchins were scraping on one end of a wooden fence and listening to the sound at the other end.

Laennec gave his version of events in an article in 1821. His patient that day was a young woman with a diseased heart, but tapping on her chest provided no information due to, as he put it, ‘the great degree of fatness’. Her age and sex meant he could not put his ear directly to her chest.

Suddenly he recalled how the scratching of a pin on one end of piece of wood could be clearly heard by placing an ear to the other end. Laennec did not immediately search around for a piece of wood, but rather made tube from 20 sheets of paper. He placed one end of the tube on the fat girls chest, the other to his ear. ‘J’ender! (I hear!) he reputedly cried, as the sounds of her ailing heart reached him with unprecedented clarity.

Laennec treated patients with heart and lung diseases at the Necker Hospital in Paris. With his new device, he was soon able to develop new methods of diagnosis, ‘a set of new signs of diseases of the chest, for the most part, certain, simple and prominent’. It was a major step forward in medical practice.

Laennec experimented with various materials, seeking the best transmission of sound. Surprisingly, solid materials like glass, metals and wood did not work as well as the column of air in his paper tube, though he quickly moved to wooden tubes 30 centimeters long, turned (reportedly) on his own lathe, with one end flared out into a bell. Some decades later the availability of flexible rubber tubes allowed the development of a ‘twoered’ stethoscope, much as we have today.

Laennec himself died of consumption (TB) aged only 45, a decade after his great invention and six weeks after returning to his native Brittany.