INVENTIONS

Rene Theophile Hyacinthe Laennec a Frenchman invented a wooden tube in 1816 which was capable of isolating the organic noises from the surrounding environment and making them louder.  Later, two hollow tubes were used so that the sounds could be heard with both ears. Laennec made two kinds of stethoscope; one was a hollow tube to examine the thorax and the other, a solid tube for examining the heart. The first type developed into two models, one was cylindrical and was used to listen to changes in the voice, the second was widened at the auricular end to listen to breathing and rattles in the throat.