Our ears allow us to detect sounds, which pass through the
air as waves of varying pressure. On reaching the ear, the waves travel through
several structures to the cochlea in the inner ear. There, receptor cells
produce signals that go to the brain. The human ear can detect sounds over a
very wide range of pitch and loudness, from the high-pitched squeaks of a mouse
to the roar of a passenger jet.
HEARING APPARATUS OF THE EAR
The outer ear channels sound waves into the ear canal. These sound
waves cause the eardrum, a thin membrane at the end of the ear canal, to
vibrate. The vibrations are transmitted via three tiny bones in the middle ear
to the cochlea in the inner ear.
Inside the cochlea, sound vibrations make these sensory hairs move,
which triggers signals in attached receptor cells. The signals pass to the
brain, which works out the pitch and loudness of the sound.
