Sound and the ear|
Sound consists of vibrations of air in the form of waves. The ear is able to
pick up these vibrations and convert them into electrical signals that are sent
to the brain. In the brain, these signals are translated into meaningful
information, such as language or music with qualities like volume and pitch. The
volume of sound is measured in decibels (dB).
Cross section of the ear
The ear consists of three parts: the outer ear, middle ear and inner ear.
Please see the diagram, over the page.
The outer ear is the visible part of the ear on either side of the head and
includes the ear canals that go into the head. The fleshy parts of the outer ear
act as "collectors" of sound waves, which then travel down the ear canal to the
eardrum. This is a membrane of tissue that separates the outer ear from the
The sound waves cause the eardrum to vibrate. This vibration is passed on to
the middle ear, which consists of three small bones called the "ossicles", which
amplify and conduct the vibrations of the eardrum to the inner ear.
The inner ear consists of an organ called the cochlea, which is shaped like a
snail's shell. The cochlea contains tiny cells called hair cells which move in
response to the vibrations passed from the ossicles. The movement of these hair
cells generates an electrical signal that is transmitted to the brain through
the auditory nerve.