Chapter 13 Flashcards
(21 cards)
humans can detect frequencies within what range?
20khz to 20 hz
middle and outer ear
collect sound waves and amplify the pressure
inner ear
where many processes allow for the frequency, amplitude, and phase of the signal to be tranduced
hair cells
are sensory receptors that will give rise to electrical activity
external ear has
the pinna, concha, and meatus
eardrum
tympanic membrane
selective hearing for human speech is around
2-5khz
middle ear function
to match the low impedance of the airborne soundwaves to the high impedance fluid of the inner ear
oval window
site where the bones of the middle ear contact the inner ear
the stapes pushes against this to match the incoming sound waves
cochlea
located in the inner ear and it is where energy is from the sound generated waves is transformed into neural impulses
kinocilium
tallest hair cell
hair cell resting potential
is around 45-60mV
depolarization
causes K and Ca to enter the cell
an influx of Ca causes NT release from the basal end of the cell to the auditory nerve endings
K + ion
can depolarize and repolarize the cell
allows the k gradient to be maintained by passive ion movement
the endolymph is
K rich and Na poor
the perilymph is
K poor and Na rich
nerve fibers at the top of the cochlea
respond to low freq
nerve fibers at the bottom end of the cochlea
respond to high frequencies
two strategies to localize sound
interaural time and interaural intensity differences
MSO
used to analyze the interaural time differences
they contain cells with bipolar dendrites that extend medially and laterally
it’s a coincidence detector bc it responds to both excitatory signals at the same time
LSO
used to compute the position and intensity of the sound source
it receives inhibitory input from the contralateral ear via an inhibitory neuron in the MNTB
its an excitatory-inhibitory interaction on the same side of the head
