How does a metal plate falling on a ground  produces noise?
 

In electronics, noise is a random fluctuation in an electrical signal, a characteristic of all electronic circuits. Noise generated by electronic devices varies greatly, as it can be produced by several different effects. Thermal noise is unavoidable at non-zero temperature (see fluctuation-dissipation theorem), while other types depend mostly on device type (such as shot noise,^[1][2] which needs steep potential barrier) or manufacturing quality and semiconductor defects, such as conductance fluctuations, including 1/f noise.
                     

Because metals are sonoures and produces sound. Therefore the metal plate falling on the ground produces sound.

because this metel is sonorous

metal plare falling on ground produces sound because metals are sonorous

because metals are sonorous. Thus they produce a sound.