how produce electrical impulse from sound vibration in a medium and what is it's principles?

Answer 1

sound vibration in a medium causes the molecules of that medium to move about a bit , affect the adjacent molecules, they move about a bit less and so it goes on. Eventually the vivbration, much attenuated, will reach the limits of the medium where it may pass into another medium or be reflected back into the first medium or a combination of both.

There are a huge number of different types of acoustic transducers designed to detect the bulk movement of these molecules and convert them into some other type of time-varying signal, often electric. do a search on "acoustic transducer" to get some idea of just how many different types there are. They work on two basic principles : a) They observe some change in the properties of the medium as sound passes through it near to the transducer.
b) They carefully couple as much of the sound energy as they can into a part of the transducer whos physical properties are very sensitive to vibration and then convert that change into a signal.

Best of Luck - Mike

Answer 2

have you heard of a microphone?? what happens is that there is a coil of copper wire attached to a diaphram and a magnet.
when sound hits the diaphram the vibration will move.
when a wire moves through a magnetic field(thanks to the magnet.) an electrical current is generated and this is the source of the electrical impulses.
God bless,
gabe