Table 1.

The evolution of the stethoscope.

Date	Inventor	Improvement
1816	Laënnec	Rolled paper cone, later a wooden tube
1828	Priorry	Funnel shaped bell, a lightened stem, and thinner earpiece for a better seal
1843	Williams	The first binaural stethoscope, using lead pipes for earpieces
1851	Marsh	Stethoscope chest piece was fitted with a flexible membrane
1855	Cammann	Binaural stethoscope with flexible tubing
1894	Bianchi	First stethoscope with a rigid diaphragm, known as a “phonendoscope”
1925	Bowles and Sprague	Combination of bell and a rigid diaphragm chest piece as used today
1945–1946	Rappaport, Sprague and Groom	Experimented with various designs to determine ideal properties for the modern binaural stethoscope – for example, a combination chest piece, short tubing with low internal volume and well fitting earpieces
1956 onwards	Various (for example, Leatham, Littman, etc)	Various modern stethoscopes have been developed with improvements to weight and appearance but using the same principles described by Rappaport, Sprague and Groom