Download The Auditory Sense: Hearing

The Auditory Sense: Hearing
EQ: What is the process though which we hear and
how do we differentiate between sounds?
Step 1: Accessory Structures of Hearing
• Sounds (A
repetitive
fluctuation in the
pressure of a
medium, such as
air) are what we
hear.
• The Pinna, in
effect, guides the
sound down the
Ear Canal to the
Tympanic
Membrane
Focus on the Tympanic Membrane
Step 2: Receptor Structures of Hearing
• Transduction in
the ear takes place
in the Cochlea.
• The Cochlea can
expand and
contract in order to
differentiate the
sound(s) being
passed into it.
Focus on the Basilar Membrane
(corti)
Step 3: Sensory Nerves of Hearing
• Once the
information has
been coded during
transduction, the
information travels
up the auditory
nerve to the
Thalamus.
Steps 4/5: Sensory Nerves of Hearing
• Once in the Thalamus,
the neural impulse is
sent to the Primary
Auditory Cortex within
the temporal lobe
• Within this structure,
the neural impulse is
decoded (Perceived)
and decisions based on
behavior occur
Sensing Loudness:
• A loud sound has a higher amplitude
• The further the distance between the peak and baseline,
the louder the sound (amplitude)
• We can measure how loud a sound is in decibels (db)
Sensing Pitch:
• Pitch refers to the frequency of sound waves measured in
hertz
• The shorter the wavelength, the higher the frequency
(pitch)
• The longer the wavelength, the lower the frequency(pitch)
Sensing Timbre:
• Timbre is the quality of a sound
• It is determined by the frequency and amplitudes of a
sound
• The best quality of timbre comes from naturally heard
sounds
Deafness:
• Deafness can be caused by several issues within the sense
of hearing.
• While some forms of deafness can be treated, others are
permanent
Conduction Deafness:
• The most common form of deafness
• Caused when the three inner bones (Malleus, Incus,
Stapes) of the ear fuse
• Can be treated through hearing aids
Nerve Deafness:
• Caused by damage to the auditory nerve or the Cortical
Cells
• Can be treated through Cochlear implants
Temporal Lobe Deafness:
• Caused by damage to the temporal lobe
• Cannot be treated