4. Each part of
the ear serves
a specific
purpose in the
task of
detecting and
interpreting
sound.
5. The Outer Ear
• Picture a satellite dish
that collects radio
waves.
• The outer ear is
similar!
– The curved formation on
the outside ( the pinna)
helps funnel sound down
the ear canal to the
eardrum.
6. The Middle Ear
• The middle
ear transfers
the energy
of a sound
wave by
vibrating the
three bones
found there.
7. Bones of the Middle Ear
Hammer
Anvil
Stirrup
Eardrum
• These are
the smallest
bones in
your body!
• Together,
they’re
about the
size of an
orange
seed.
9. How Sound Travels in the
Middle Ear
• When sound waves
reach the middle ear,
they cause the
eardrum to vibrate.
• This vibration then
causes the three
bones to vibrate.
• These vibrations are
transformed into
longitudinal/pressure
waves in the middle
ear.
15. The Auditory Nerve
• The tiny hair cells
of the cochlea are
set in motion by
vibrations
• The vibrations
stimulate tiny
nerve cells.
• The nerve cells
then send signals
along the auditory
nerve to the brain.
17. Put the following steps in order:
A. The stirrup moves back and forth,
creating pressure waves in the
cochlea.
B. The bones of the middle ear
(hammer, anvil, & stirrup) vibrate.
C. Hair cells send an electrical
impulse through the auditory
nerve.
D. The outer part of the ear (the
pinna) "catches" the sound waves.
E. Sound waves vibrate the eardrum
F. The brain receives an electrical
impulse and interprets it as sound.
G. Tiny hair cells in the cochlea move
as the waves pass.
H. The sound waves travel into the
ear canal.
D
H
E
B
A
G
C
F