This work discusses the evolution of the stethoscope which means "chest-seeing device". The first stethoscope was created by R.T.H. Laennec in 1816. Laennec's monoaural, paper-roll stethoscope was succeeded by his hollow, wooden, cylindrical, monaural instrument. From the monaural stethoscope emerged binaural stethoscopes, hydraulic stethoscopes which was designed for auscultatory percussion, and the present-day stethoscope with a stiff diaphragm. The present-day stethoscope accentuates high-pitched sounds which is characteristic of respiration and turbulent flow, whereas the older bell receiver accentuates the lower-frequency sounds. There also came about the combined bell and diaphragm stethoscope and the stereophonic stethoscope called the symballophone. In time, the stethoscope has become the badge of the physician.