In 1816 at a Paris hospital, physician René Laennec was called to examine a young woman with the signs of heart disease. Tapping her chest told him little through the extra tissue, and pressing his ear to her bare chest, the accepted method then called immediate auscultation, broke the social propriety of the day. Remembering that a pin scratched at one end of a solid piece of wood can be heard clearly at the other end, a game he had seen children playing in the Paris streets, he rolled a quire of paper into a tight cylinder and heard her heart more clearly than he ever had with his bare ear. This episode traces Laennec from his 1781 birth in Quimper, Brittany, through a sickly childhood, the death of his mother from tuberculosis when he was five, and years spent carving and playing wooden flutes, to medical study in Paris under Jean-Nicolas Corvisart, champion of chest percussion.

Laennec built a wooden tube about 25 centimeters long and matched what he heard in living patients to what he found at autopsy, mapping the sounds of disease. His 1819 book on mediate auscultation named the stethoscope from the Greek words for chest and examination and introduced terms doctors still use. He also named cirrhosis and lectured on melanoma as a student in 1804, which set off a lasting feud with his former teacher Dupuytren. Many physicians resisted the tube for decades. Then Laennec contracted tuberculosis himself, was diagnosed by his nephew Mériadec using his own invention, and died in August 1826 at 45.

• Why chest tapping, as Corvisart taught it, revealed density but not the details of disease
• Rales, rhonchi, crepitance and egophony, the voice that sounds like a bleating goat through fluid around the lungs
• A professor’s 1885 advice to use ears and not a stethoscope, and L.A. Conner’s silk handkerchief
• Laennec’s will, which called his stethoscope the greatest legacy of his life
• The binaural rubber-tube stethoscope of the 1850s, Kipling’s Rewards and Fairies and the 1949 film Dr. Laennec