lecture 18 (test 2)

Question 1

how many auditory nerves innervate each hair cell

Answer 1

5-30

Question 2

transmission occurs though the cochlear brach via the

Answer 2

vestibulocochlear nerve

Question 3

where do cell bodies of afferent fibers lie

Answer 3

in the cochlear ganglion

Question 4

afferent axons synapse within the

Answer 4

brainstem

Question 5

hair cells are innervated with afferent fibers in what fashion

Answer 5

systematic and topographic fashion

Question 6

characteristic frequency

Answer 6

lowest point on tuning curve

frequency at which afferent fiber is most sensitive

Question 7

how do we obtain a tuning curve

Answer 7

absolute threshold experiment

take electrode and place in auditory nerve near a nerve fiber

Question 8

fibers that innervate near the base of the basilar membrane respond most strongly to

Answer 8

high frequencies

Question 9

what are the 2 ways we encode sound frequency

Answer 9

1) looking at response of individual auditory nerve fibers

2) looking at pressure changes of sound wave

Question 10

what is it called to look at the pressure changes in a sound wave

Answer 10

phase locked response

Question 11

true phase locking can only occur up to

Answer 11

400-500 Hz

Question 12

volley principle

Answer 12

neurons work together to create a high frequency response

dispersed phase locking up to 4000Hz

Question 13

can neurons actually fire at 10 000Hz

Answer 13

nope

Question 14

temporal code

Answer 14

states the firing rate of an auditory nerve attached to a hair cell will match the incoming sound frequency

Question 15

how long is a average AP

Answer 15

2ms

Question 16

low spontaneous fibers

Answer 16

• low action potential frequency
• high activation threshold
• activates at high intensities
• saturates higher intensities
• does not fire till sound is loud

Question 17

high spontaneous fibers

Answer 17

• high action potential frequency
• low activation threshold
• activates at low intensities
• very sensitive
• plateau at about 30 dB

Question 18

auditory system determines frequency of incoming sound by looking at

Answer 18

pattern of firing across ALL afferent nerve fibers

Question 19

contralateral

Answer 19

opposite side

Question 20

ipsilateral

Answer 20

same side

Question 21

where does spinal ganglion synapse onto

Answer 21

CNS in the medulla

Question 22

what are cochlear nuclei sensitive to

Answer 22

each only sensitive to sound from one ear

Question 23

where does the calculation occur that determines when sound reaches each ear

Answer 23

superior olive

Question 24

response modification

Answer 24

auditory signals are processed to some degree in some structures, excitement and inhibition occurs at each relay site

Question 25

tonotopic organization

Answer 25

place code

Question 26

laterality

Answer 26

extent to which subcortical structures can be separately driven by the 2 ears

Question 27

most neurons above what are binaural

Answer 27

cochlear nucleus

Question 28

contralateral inputs are usually

Answer 28

excitatory

Question 29

ipsilateral inputs are usually

Answer 29

excitatory or inhibitory

Question 30

as we get closer to auditory cortex there is

Answer 30

more integration from both sides

Question 31

where is the primary auditory cortex located

Answer 31

superior temporal gyrus in the temporal lobe

Question 32

where is the secondary auditory cortex (V2) located

Answer 32

directly surrounding the primary auditory cortex

Question 33

what does area V2 process

Answer 33

more complex signals

Question 34

conductive hearing loss

Answer 34

when outer or middle ear are affected, leading to reduced transmission of sound to the cochlea

Question 35

congenital hearing loss

Answer 35

hearing loss in children before language development causes deaf-mutism the absence of language vocalization ability can be genetic or caused by an issue in the birth process

Question 36

acquired hearing loss

Answer 36

occurs later in life

Question 37

Otitis media

Answer 37

middle ear infection inflation of the eustachian tube changes ear drum transmission fluid build-up interferes with ossicle vibration prevalent in children (tube smaller and more horizontal)

Question 38

Otosclerosis

Answer 38

inherited bone disease, producing abnormal development and function of the ossicles increased accumulation of calcium on ossicles surgeons can shave off to allow vibration again advances in microsurgery allow ossicle repair or replacement

Question 39

sensorineural hearing loss

Answer 39

``` more common and most frequent damage to hair cells or auditory nerve causes may include: ingestion of toxins traumatic injury tumor disease noise-induced hearing loss (NHL) ```

Question 40

do our hair cells regenerate

Answer 40

nope

Question 41

types of hereditary hearing loss

Answer 41

Usher syndrome | Waardenburg syndrome

Question 42

presbycusis

Answer 42

hearing loss that occurs gradually by effects of aging | loss begins with high-frequency sounds

Question 43

otolaryngologists (ENT)

Answer 43

clinical diagnosis of auditory disorders

Question 44

audiologists

Answer 44

evaluate hearing function

Question 45

tests audiologists use

Answer 45

Rinne test

Question 46

conductive hearing loss rinne results

Answer 46

louder when tuning for on bone than in air

Question 47

hearing aids work better when

Answer 47

work better when no hair or cochlear function is impaired

Question 48

components of hearing aid

Answer 48

small microphone electronic amplifier small speaker

Question 49

the main problem with hearing aids

Answer 49

don't want to amplify all noises