Hi . Nice piece. By the way, you have mentioned that:
Stethoscope is an electronic device normally use by medical practitioners to listen to the sound that is coming out internally from human body or an animal and blood pressure (BP) in veins and arteries.
The term "electronic" here describe only a portion of all the stethoscope. Not all are electronic so if it were up to me, I would write "Stethoscope is a device....." instead.
RE: The science and working principle of stethoscope