CBSE Class 9 Answered

Our ears are the sensory organs that help us to hear.

Sound waves are produced by the vibration of atoms in the air . When these waves reaches our ear it hits eardrum , then it is recognised by the brain, so we hear sound.

The mechanism hearing can be explained as below. First you need to understand the parts of the human ear.

The Outer Ear - It consist of the pinna and the eartube. The eardrum is a tightly streched membrane that seperates the outer ear from the middle ear.

The Middle Ear - It consist of three tiny interlocked bones. The innermost bone is connected to the inner ear by a tiny window.

The Inner Ear - It consists coiled organ of hearing, semicircular tubes called the organ of balance and the auditory nerves.

• When an object produces sound, the sound is collected by the pinna and passed to the eartube. 

• The sound then strikes the eardrum that makes the eardrum vibrate with the same frequency. This then makes the delicate interlocked bones to vibrate. 

• The vibrations are converted into electical impulses.These impulses reach the brain through the auditory nerve and the brain interprets the impulses and then we can hear the sound.

The diagram is show below :-