Audition

Question 1

amplitudes of sound waves corresond to ??

Answer 1

loudness

Question 2

normal speech is how many decibels?

Answer 2

60

Question 3

frequency of sound waves corresponds to ??

Answer 3

pitch

Question 4

humans can detect what frequency ranges?

Answer 4

20 Hz- 20kHz

Question 5

complexity of sound waves corresponds to ??

Answer 5

timbre- quality of sound

Question 6

presbycusis

Answer 6

hearing loss associated w/ old age, usually an age dependent loss of high frequency range

Question 7

attenuation reflex

Answer 7

tensor tympani and stapedius muscles stiffen the ossicles in response to loud sounds

Question 8

tensor tympani muscle is innervated by what? stapedius muscle innervated by?

Answer 8

trigeminal, facial

Question 9

3 bones of the middle ear

Answer 9

malleus, incus, stapes

Question 10

outer ear function

Answer 10

boosts sound pressure around normal human speech 30-100x

Question 11

middle ear function

Answer 11

vibrational energy moves tympanic membrane, which is translated via ossicles to oval window

boosts 200 fold

Question 12

function of eustachian tube

Answer 12

equalize pressure between ear and nasopharnyx

Question 13

3 different chambers of the cochlea

Answer 13

scala vestibuli- perilymph

scala tympani- perilymph

scala media- endolymph

Question 14

what produces endolymph

Answer 14

stria vascularis in scala media

Question 15

basilar memebrane organization

Answer 15

sound vibrations create a wave inside the basilar membrane

narrower and stiffer at the base- high frequency sounds vibrate more

wider and more flexible at the end- low frequency sounds vibrate more

Question 16

tip link

Answer 16

protein complexes that connect K channels at the tip of one stereocilia to the shaft of another

when opened, allow K into cell

Question 17

directionality of stereocilia

Answer 17

pushing the stereocilia one way causes hyperpolarization,

pushing the other way causes depolarization

Question 18

describe the physiology of hair cells

Answer 18

high [K] outside hair cells causes a large chemical and electrical gradient into the cell

opening channels causes K to flow into cell and depolarization

this triggers Ca release, which causes vesicle release into afferent synapses

Question 19

what determines the positional development of hair cells

Answer 19

BMP7 and retonic acid develop gradients down cochlea during development

more stereocilia closer to base, shorter

less stereocilia near apex, longer

Question 20

tectorial membrane

Answer 20

lies on top of stereocilia, displacement of basilar membrane causes shear against tectorial membrane

Question 21

function of efferent axons

Answer 21

efferent hair cells exhibit electromotility- change shape w/ changes in potential

when hair cells are short, allows for greater vibration of basilar membrane and more signal

when hair cells are long, dampens vibration and causes less signal

Question 22

prestins

Answer 22

motor proteins sensitive to membrane potential- causes change in shape in outer hair cells

Question 23

furosemide

Answer 23

interferes w/ outer hair cells contraction- decreases cochlear amplifier

Question 24

the optimal frequency of hair cells is determined by what?

Answer 24

intrinsic- ion channels it expresses

extrensic- position on the basilat membrane

Question 25

tonotopic projections to cochlear nuclei

Answer 25

similar to basilar membrane, there is an organization by frequency in cells in the cochlear nucleus

Question 26

describe the cochlear nuclei

Answer 26

found in rostral medulla dorsal- frequency info ventral- intensity info

Question 27

list the auditory pathway

Answer 27

cochlear nuclei- superior olive - nucleus of lateral leminscus - inferior colliculus - medial geniculate - auditory cortex

Question 28

describe sound localization

Answer 28

1 time delay in 2 ears- time delay calculated by medial superior olive 2 by comparing intensity differences between ears- sensed by lateral superior olive (ipsilateral LSO excited, contralateral LSO inhibited) 3 phase differences; used w/ low frequency sounds. sounds arrive at 2 different times in their wave cycle 4 vertical location- uses timbre to localize vertical location

Question 29

inferior colliculus function

Answer 29

integration of auditory w/ somatosensory startle response filtering out of self-generated sounds

Question 30

medial geniculate of thalamus function

Answer 30

relay station to cortex

Question 31

where is the primary auditory cortex

Answer 31

superior temporal lobe, right below sylvian fissure. maintains tonotopic organization

Question 32

secondary auditory cortex

Answer 32

"belt areas" specific for combinations of sounds, specific durations, or specific patterns of sounds wernickes area- important for speech comprehension

Question 33

dual streams of auditory info

Answer 33

ventral- primary auditory- inferior frontal gyrus- important for pitch dorsal stream- superior parietal cortex- superior frontal gyrus- important for localization

Question 34

brocas area

Answer 34

important for generating speech premotor area

Question 35

arcuate fasciculus

Answer 35

white matter tract that connects wernickes and brocas areas

Question 36

supramarginal gyrus

Answer 36

matches incoming sounds with phonemes

Question 37

angular gyrus

Answer 37

important for matching graphemes to phonemes

Question 38

mcgurk effect

Answer 38

when presented with one sound and a visual image of a face making a different sound

Question 39

hyperacusis

Answer 39

extra sensitivity to low intensity sounds damage to tympani or stepadius muscles bells palsy

Question 40

auditory agnosia

Answer 40

inability to identify meaning of a non verbal sound

Question 41

congenital amusia

Answer 41

tone deafness (hereditary) cant detect changes in pitch

Question 42

conduction deafness

Answer 42

loss of conduction of sound from outer ear to cochlea

Question 43

sensorineural deafness

Answer 43

loss of hair cells or neurons in auditory nerve

Question 44

acquired hearing loss

Answer 44

main causes: trauma, infection, drugs (strepamicin or gentamicin)

Question 45

genetic hearing loss

Answer 45

many involve channels and transporters involving K concentrations

Question 46

tinnitus

Answer 46

ringing in ears w/o stimulus

Question 47

acoustic neuroma

Answer 47

slow growing benign tumor in elderly pts from schwann cells presses on inner ear and causes vestibular or auditory symptoms

Question 48

menieres disease

Answer 48

endolymphatic duct gets blocked and causes pressure buildup