Before describing the stethoscope amplification’s
mechanism it is important to note that: (a) a
stethoscope prevents dispersion of sound intensity.
It is known that sound’s intensity dwindles by r
1
4 2
as the distance r from the sound source increases.
The stethoscope’s tube, through which sound travels,
prevents its intensity dispersion. (b) The stethoscope’s
earphones, which are inserted into the ears,
reduce background noise, thus, allowing attention
to be focussed on the sound coming from the target
source. Although (a) and (b) are not part of the
amplification process, they both contribute to the
hearing improvement produced by a stethoscope.