The stethoscope was invented in France in 1816 by René
Laennec at the Necker-Enfants Malades Hospital in Paris. It consisted of a
wooden tube and was monaural. His device was similar to the common ear trumpet,
a historical form of hearing aid; indeed, his invention was almost
indistinguishable in structure and function from the trumpet, which was
commonly called a "microphone". The first flexible stethoscope of any
sort may have been a binaural instrument with articulated joints not very
clearly described in 1829. In 1840, Golding Bird described a stethoscope he had
been using with a flexible tube.
Bird was the first to publish a description of such a
stethoscope but he noted in his paper the prior existence of an earlier design
(which he thought was of little utility) which he described as the snake ear
trumpet. Bird's stethoscope had a single earpiece. In 1851, Irish physician
Arthur Leared invented a binaural stethoscope, and in 1852 George Cammann
perfected the design of the instrument for commercial production, which has become
the standard ever since.
Cammann also wrote a major treatise on diagnosis by auscultation,
which the refined binaural stethoscope made possible. By 1873, there were
descriptions of a differential stethoscope that could connect to slightly
different locations to create a slight stereo effect, though this did not
become a standard tool in clinical practice.The medical historian Jacalyn
Duffin has argued that the invention of the stethoscope marked a major step in
the redefinition of disease from being a bundle of symptoms, to the current
sense of a disease as a problem with an anatomical system even if there are no
noticeable symptoms. This re-conceptualiization occurred in part, Duffin
argues, because prior to the stethoscopes, there were no non-lethal instruments
for exploring internal anatomy.
