The Stethoscope used by a medical practitioner is based on the phenome

The Stethoscope used by a medical practitioner is based on the phenomenon of :

multiple reflection of sound waves.
scattering of sound waves.
refraction of sound waves.
none of the above.
This question was previously asked in
UPSC CAPF – 2010
The stethoscope works based on the phenomenon of multiple reflection of sound waves.
– Sound waves generated inside the body (like heartbeats or breathing sounds) are collected by the diaphragm (or bell) of the stethoscope.
– These sound waves travel through the hollow tube. As they travel, they undergo multiple reflections off the inner walls of the tube.
– These repeated reflections guide the sound waves towards the earpieces, concentrating the sound and making it audible to the medical practitioner.
While sound can scatter or refract, the primary mechanism by which sound is transmitted and focused through the stethoscope tube to the listener’s ears is multiple internal reflection.