A labelled diagram of the ear is given below.
As is seen from the figure, the ear consists of three main parts namely (i) outer ear (it) middle ear (iii) inner ear.
When sound enters the outer ear, it is directed to the eardrum along the auditory canal. The eardrum is a membrane which starts vibrating. The vibrations are transmitted through the middle ear through a set of is in the middle ear that the wave pressure is amplified. The amplified pressure wave enters the inner ear which includes semicircular canals and cochlea. It is in the cochlea that sound waves are translated into nerve impulses and the pitch or frequency discrimination is made when a region of the membrane is set into vibration by sound of a particular frequency, hair cells in that region are translated. The resulting nerve impulses are sent to the brain and are interpreted as sound.