Audition

Question 1

3 parts of outer ear

Answer 1

1. Pinna
2. Ear canal
3. Tympanic membrane

Question 2

2 functions of pinna

Answer 2

1. Selectively amplifies frequencies within speech range

2. Enhances sound localization ability

Question 3

Tympanic membrane relays info to

Answer 3

Malleus

Question 4

2 ossicles (out to in)

Answer 4

Malleus
Incus
Stapes

Question 5

Middle ear compromise causes

Answer 5

Conductive hearing loss

Question 6

Staples relays info to

Answer 6

Oval window

Question 7

Reissner’s membrane separates

Answer 7

Cochlear duct from scala vestibuli

Question 8

Basilar membrane separates

Answer 8

Cochlear duct from scala tympani

Question 9

The organ of corti is covered by? floating in?

Answer 9

tectorial membrane

endolymph

Question 10

What makes endolymph

Answer 10

stria vascularis

Question 11

Main differences between IHC and OHC

Answer 11

1. one row IHC, three rows of OHC
2. 90% of fibers innervate IHCs
3. 10 fibers innervate IHCs,

Question 12

The tallest stereocilia is

Answer 12

Embedded in the tectorial membrane

Question 13

2 functions of hair cells

Answer 13

1. Mechano-electrical transduction

2. Neurotransmission

Question 14

Which neurons are more sharply tuned?

Answer 14

Those with high best frequencies

Question 15

What are cochlear cell tuning curves?

Answer 15

Reactivity of hair cells to their best frequency

Question 16

Spontaneous ear noises are called

Thought to be caused by

Answer 16

Oto-acoustic emmissions
OHC electromotility: amplifies traveling wave in a positive feedback system. Cell length changes length in response to an electrical stimulus by a confomational change in motor protein in the lateral wall

Question 17

What is the pattern of auditory nerve firing

Answer 17

1. Brisk firing at onset of stimulus
2. Plateaus with adaptation
3. Transient drop out with termination of stimulus

Question 18

2 ways neurons code signal

Answer 18

1. Place code: fibers are in a tonotopic map relating to best frequency
2. Frequency code: firing rate reflects stimulus frequency

Question 19

Where does signals from both ears meet first?

Answer 19

Olivary nucleus

Question 20

4 stops after olivary nucleus?

Answer 20

1. Lateral lemiscus
2. Inferior colliculus
3. Medial geniculate nucleus
4. Cortex

Question 21

2 Functions of cochlear nucleus

Answer 21

1. Switchboard sending auditory info

2. processing time and frequency info

Question 22

What is the acoustic reflex

Answer 22

Tightening of stapedious muscle in response to loud noises

Question 23

What forms the outer wall of the scala media

Answer 23

Stria vascularis

Question 24

2 directions of hair cells and response

Answer 24

1. Toward kinocilium: Depolarization

2. Away from kinocilium: hyperpolarization

Question 25

3 subdivisions of Olivary Nucleus and functions

Answer 25

COINCIDENCE DETECTORS
MSO: sound localization using interaural delay cues
LSO: localization using intensity cues
Superior Olivary Complex: projects to inferior colliculus

Question 26

What kind of map does the IC have

Answer 26

Spatio-topic map of auditory environment