What is meant by loudness of sound?

What is meant by loudness of sound? State the factor on which it depends. Draw figures to illustrate
(i) soft sound and (ii) loud sound.

Loudness It is the measure of sound energy reaching the ear per second. Greater the sound energy reaching our ears per second, louder the sound will appear to be.
It depends on the amplitude of the sound wave, which depends upon the force with which an object is made to vibrate.
(i) Wave disturbance

(ii) Wave disturbance