In this method we could convert sound energy to heat energy
as sound wave travel by oscillating the particles of the
medium so when sound energy travel through the medium it
will disturbs the particle of the medium these disturbance
created by sound will be used to convert it into heat energy
as when the particles of the medium will be pushed by the
sound wave it will collides with adjacent particle of the
medium this collision will result production of heat energy
the production of heat energy will be more in the denser
medium so for more heat production we will need a material
with very high density. This heat energy will be converted
into electricity