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Hearing – How We Hear Sound
Introduction
 Ears are __________________ organs that respond to sound.
 Your ear converts __________________ waves into nerve
impulses that your __________________ interprets.
 The ear’s structure is designed to __________________ and
__________________ the sound waves.
Parts of the Ear
 The OUTER EAR
 Contains the __________________, ear canal and
eardrum
 The MIDDLE EAR
 Contains 3 bones: hammer, __________________ and
stirrup
 The INNER EAR
 Contains the cochlea and __________________ nerve
The Outer Ear
 The ______________ is specially shaped to _______________
and focus sound waves and direct them into the ear.
 The ear __________________ is a hollow tube that carries the
sound waves to the __________________.
 The sound wave hits the eardrum, causing it to
__________________. The eardrum transmits these
vibrations into the inner ear where they are ______________.
The Middle Ear
 The middle ear has the __________________ bones in the
body: the __________________, anvil and _______________.
 Their job is to __________________ the vibrations of the
eardrum and transmits it into the __________________ear.
 The stirrup “__________________” on the inner ear at a spot
called the __________________ window.
The Inner Ear
 The inner ear has the __________________ which is a
__________________-shaped tube that is lined with receptors
that respond to sound.
 The receptors are tiny __________________ cells that shake
back and forth in response to sound waves.
 When they __________________, the hair cells create nerve
__________________ which go to the brain along the
auditory nerve.
High vs. Low Sounds
 Higher pitch sounds carry __________________ energy and
travel further into the cochlea.
 Lower pitch sounds carry __________________ energy and
don’t travel as far into the cochlea.
The Auditory Nerve
 The cochlea sends __________________ signals to the brain
through the __________________ nerve, where the brain
translates these signal into sound.
 Any interruption of this process can be a cause for
__________________.
The Main Ideas
 The ear is divided into 3 sections: the __________________
ear, middle ear and __________________ ear.
 At the outer ear, __________________ waves are focused by
the pinna down the ear canal to the eardrum.
 The sound waves make the eardrum __________________.
 The vibrations are amplified by the _______ middle ear bones:
the hammer, anvil and stirrup.
 The stirrup __________________ the vibrations to the cochlea
within the inner ear.
 The vibrations activate the __________________ cells inside
the cochlea, which send __________________ signals to the
brain along the auditory nerve.
 The __________________ interprets these signals as sound.