Laennec remembered a childhood trick "a simple fact in acoustics;the great distinctness with which we hear the scratch of a pin at one end of a piece of wood, on applying the ear to the other."
He made a "log" by rolling sheets of paper into a cylinder. Laennec applied one end of it to the region of the heart and the other to his ear, and was surprised to hear a clear and distinct sound that allowed him to perceive the action of the heart.
This led to the invention of Laennec's monaural stethoscope in 1819. On the basis of his knowledge of normal and abnormal breath sounds, Laennec could diagnose bronchitis, pneumonia, and most importantly, tuberculosis, a prevalent disease that claimed many lives at the time.
Ironically, Laennec himself died of tuberculosis in 1826.

See as them dey smooch in the name of listening to heart beat!

They should have kept the tradition

You all that love these method,you gat sister and mother,what of reverse is the case?