Structure of Human Ear

→ The ear consists of three parts: outer ear, middle ear and inner ear.

→ The ears are the sense organs which help us in hearing sound.

→ The outer ear is called pinna. It collects the sound from surroundings.

→ This sound passes through the auditory canal.

→ At the end of auditory canal, is a thin elastic membrane called ear drum or tympanic memb

→ The middle ear contains of three bones: hammer, anvil and stirrup linked with one another. F

end of hammer touches ear drum and that of stirrup linked with membrane of oval window of


→ The lower part of middle ear has a narrow ‘Eustachian tube’.

→ The inner ear has a coiled tube called cochlea, which is connected with oval window. Cochle

filled with a liquid containing nerve cells.

→ Other side of cochlea is connected to auditory nerve which goes to brain.

Working of Human ear

Pinna → Ear canal → Ear drum → Hammer → Anvil → Stirrup → Oval window → Cochlea → Audi

nerve → Brain

→ When compression of sound wave strikes the ear drum, the pressure on the outside of ear d

increases and pushes the ear drum inwards.

→ While during rarefaction ear drum moves outwards. Thus, ear drum starts vibrating back an


→ These vibrations are increased by three bones and middle ear transmits these amplified pre

variations received from sound waves to inner ear.

→ In the inner ear the pressure variations are turned into electric signals by the cochlea.

→ These electric signals are sent to the brain via auditory nerve and the brain interprets them