The document summarizes the history and development of the stethoscope. It describes how the stethoscope was invented in 1816 by Rene-Theophile-Hyacinthe Laennec as a cylindrical wooden device. It then discusses the development of the binaural stethoscope in the 1850s, which used two ears. Finally, it briefly explains how modern acoustic stethoscopes transmit sounds via air-filled tubes to the listener's ears.

2.  A stethoscope is a
medical
instrument used
to listen to sounds
produced in the
body, especially
those that
emanate from the
heart and lungs

4. The stethoscope is a very
important noninvasive tool used
by medical professionals and all
health care workers and
students will be trained in the
use of them.

6. AFrench doctor
named Rene-
Theophile-
Hyacinthe
Laennec
invented the
first
stethoscope in
1816.

7.  This cylindrical
stethoscope is made
with three parts
fitting together by
wood screw thread
and brass tube
fitting with an
overall length
of 12.6 inches and a
diameter of 1.5
inches. Both ends
are slightly concav

8. Picture after the fresco by Theobold Chartan
in the Sorbonne commemorating the
invention of the stethoscope in 1816. The
photo on the right shows Laennec examing a
young boy by "mediate" auscultation with his
stethoscope. The picture is taken fromm a
painting by Robert A. Thom, copyrighted
in 1960.

9.  In the early 1850's
there was a rush of
designs for a new
stethoscope that
used both ears. This
new
'Bi-aural' or
'Binaural'
instrument was felt
to be the future of
auscultation.

10. The idea belonged to Nicholas Comins, who
devised a stethoscope that he
described as "a bent tube" that had several
hinges, allowing the physician to not have to
assume
uncomfortable positions during the
examination. He offered the suggestion of
making his
instrument binaural, and may have, as there
are only sketches of his instrument.

11.  Acoustic
stethoscopes are
familiar to most
people, and
operate on the
transmission of
sound from the
chest piece, via
air-filled hollow
tubes, to the
listener's ears

12. audible sounds are
magnified through
an amplifier to
earphones, of which
there may be more
than one set, and
may be broadcast
through
loudspeakers, but in
both instances the
results are mediocre

13.  http://www.heartdiseasesympton.com/articles/
heart-disease-symptom-21.html
 http://discoverd-
world.blogspot.com.au/2011/05/discovery-
history-stethoscope.html
 http://inventors.about.com/gi/dynamic/offsite.
htm?site=http://www.antiquemed.com/tableof
con.htm
 http://www.instabriefs.com/medical-
devices/stethoscopes/stethoscopes-fast-
facts.php
 http://www.antiquemed.com/test/binaural_stet
hoscope.htm