Structure of the human ear
Tanusri Gururaj, Academic content writer of Physics at Edumarz
We can hear sounds with the help of an extremely sensitive device known as the ear.
Pressure variations in the air with audible frequencies get converted into electrical signals. These signals then travel to the brain via the auditory nerve.
The different parts of the human ear are shown in the figure below.
Functions of various parts of the ear:
Outer ear or pinna:
Collects sounds from the surroundings.
Auditory canal:
The collected sound is passed to the eardrum or tympanic membrane via the auditory canal.
Eardrum/tympanic membrane:
The eardrum is a thin membrane that collects compressions and rarefactions.
When the eardrum collects a compression, the pressure outside the membrane rises, causing the eardrum to move inward. When a rarefaction reaches the ear, the eardrum moves outward.
Ear bones:
The three ear bones are hammer, anvil, and stirrup.
These three bones amplify the vibrations several times in the middle ear.
Middle ear:
The amplified pressure variations received from the sound waves are sent to the inner ear using the middle ear.
Inner ear:
The pressure variations received from the middle ear are converted to electrical signals by the cochlea inside the inner ear.
Auditory nerve:
It sends electrical signals to the brain. Then, the brain interprets them as sound.