1. Whether driving in the car or reading books in the library , sound gives us information about the WORLD around us. It serves two basic functions : SIGNALLING and communication.

2. Sound is PRODUCED when something vibrates. The vibrating body causes the medium around it to vibrate. Vibrations in air are called traveling longitudinal waves , which we can hear.

3. Sound is a longitudinal wave and it needs medium to travel . The sound we hear everyday TRAVELS through air. And that travels by compression and decompression of air.

4. There are 6 basic steps of how do we hear sound:

a. The sound transfers into the ear canal and causes the ear drum to move.

b. The ear drum vibrates with different sounds.

c. The sound vibrations make their way through the ossicles to the cochlea.

d. Sound vibrations make the fluid in the cochlea travel like ocean waves.

e. The vibrations in the fluid causes hair cells to move. The auditory nerves then picks up the neural signals created by the hair cells. The hair cells at one end of the cochlea transfer low pitch sound info and the hair cells at the other end of the cochlea transfer HIGH pitch sound info.

f. The auditory nerve then transmits the signal to brain which is then translated into recognizable and meaningful sound.

Hope u have understood