Before the invention of stethoscopes, physicians had to place their ear on the patients chest to hear their heart beat. Réné-Théophile-Hyacinthe Laënnec found embarrassment in this when examining a female patient, so he looked for an alternative. He found that by rolling up 24 sheets of paper and putting an ear to one end, sounds from the other end were amplified and made clearer. This design is known as monaural since only one ear is involved. More sophisticated monaural stethoscopes were created out of wood.  Soon thereafter, binaural stethoscopes were made with ear-pieces for both ears, and these were sold commercially starting in 1851. There is some debate over whether or not physicians during the civil war used these instruments. However, physicians around this time found that stethoscopes were vital for making accurate diagnoses by hearing the intricate sounds of the heart and respiratory system. The stethoscope revolutionized the field of patient examination around the time of the civil war and reconstruction.

*Picture from Microsoft Encarta Encyclopedia