PSYC 213 Lecture Notes - Lecture 7: Basilar Membrane, Auditory Cortex, Cochlea
16 May 2018
School
Department
Course
Professor
Lecture 007 - 01/30/2018
Guest Lecture
• Auditory perception:
• Perception: a dynamic & integrated process that combines info from sense
organs w/ memories of past experiences, expectations of likely future actions,
attention, motivation & context
• From the ear to the brain:
• What is sound: change in air pressure → sound waves travel from location to the
ear
o Displacement over distance + magnitude of how much air is going to be
displaced
• Displacement of air: have to talk about frequency & amplitude → when
combined, perceived as loudness
• Sound waves are travelling and reach the ear: the air will come to outer ear and
then will go through ear canal and reach the tympanic membrane (eardrum)
causing it to vibrate which will push on the 3 ossicles (move and knock on inner
ear, especially in the cochlea)
o In the inner ear, changes signal from air in vibrations to movement in fluid
• In ear, also have vestibular system important for balance & gate
• Cochlea: mechanical to neural transduction happens in the cochlea → ossicles
start moving and they push on to the cochlea and in the cochlea have fluid which
will move
• When fluid starts moving: in the cochlea have the basilar membrane that have
hair cells on top so when fluid moves, the hair cells move and the movement of
the hair cells causes neural transduction
• Specific locations are sensitive to specific sound frequencies = tonotopy of the
basilar membrane
o At the base: sensitive to high frequency vs at the apex: sensitive to low
frequency aka specific frequencies resonate at different locations along
the basilar membrane
• Auditory cortex projections to other brain areas:
o For speech production/ understanding: can have other projections onto
other parts of the brain from the auditory cortex (ie: Wernicke’s area or
Broca’s area)
o To play a music: projection from AC to motor cortex when playing an
instrument
o To associate sound with emotion: projection from AC to limbic system
o And many more… the path doesn’t end at the auditory cortex
• Acoustic and perception of sound
Physical properties of sound
Perception of sound
find more resources at oneclass.com
find more resources at oneclass.com
