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Gestalt
Principles
Perceptual
Constancies
Basic
Principles
Visual
Illusions
Depth
Perception
Perception
Sensation
Vision
Hearing
We are
here
Theories
The Eye
Pain
Other
Senses
Taste
The Ear
Smell
Theories
Hearing
Our auditory sense
We hear sound WAVES
• The height of the wave gives us the amplitude of the
sound.
• The frequency of the wave gives us the pitch if the sound.
Transduction in the ear
• Sound waves hit the eardrum
then anvil then hammer then
stirrup then oval window.
• Everything is just vibrating.
• Then the cochlea vibrates.
• The cochlea is lined with mucus
called basilar membrane.
• In basilar membrane there are
hair cells.
• When hair cells vibrate they
turn vibrations into neural
impulses.
• Sent then to thalamus up
auditory nerve.
It is all about the vibrations!!!
Pitch Theories
Place Theory and Frequency Theory
Place Theory
• Different hairs vibrate
in the cochlea on the
basilar membrane when
they different pitches.
• So some hairs vibrate
when they hear high and
other vibrate when they
hear low pitches.
• But this doesn’t explain
low-pitch since we
haven’t found specific
positions for those on
the BM
Frequency Theory
• All the hairs vibrate
but at different
speeds.
– If the frequency of the
sound is 100 waves per
second then the neuron
fires at 100 pulses per
second.
– But we can hear
frequencies above 1000
waves per second but
can’t fire neurons faster
than 1000 pulses per
second.
Deafness
Conduction Deafness
• Something goes wrong
with the sound and the
vibration on the way to
the cochlea.
• You can replace the
bones or get a hearing
aid to help.
Nerve (sensorineural)
Deafness
• The hair cells in the cochlea
get damaged.
• Loud noises can cause this
type of deafness.
• NO WAY to replace the hairs.
• Cochlea implant is possible.
Cochlear Implants
Cochlear implants are electronic devices
that enable the brain to hear sounds.