Unit 3: Audition

Question 1

L1: _____ of sound is encoded by the frequency of afferent nerve fiber action potentials

Answer 1

Intensity

Question 2

L1: _____ of sound is encoded by the position along the cochlea where the afferent nerve fiber innervates the IHC.

Answer 2

Frequency

Question 3

L1: ______ rely on the spatial separation of ears and direction-dependent differences in path lengths to localize sounds.

Answer 3

Interaural time delays

Question 4

L1: At the ____ of the cochlea, the basilar membrane is thinner, narrower, and more rigid.

Answer 4

base

Question 5

L1: At the ____ of the cochlea, the basilar membrane is wider, thicker, and more flexible.

Answer 5

apex

Question 6

L1: Depolarization of IHCs leads to release of ____ to signal an afferent nerve fiber.

Answer 6

glutamate

Question 7

L1: In the primary auditory cortex, neurons representing ____ frequencies are located more anteriorly.

Answer 7

lower

Question 8

L1: Influx of _______ occurs during mechanosensitive depolarization of IHCs.

Answer 8

potassium

Question 9

L1: Interaural level differences are used for effective localization of ______-frequency sounds.

Answer 9

High

Question 10

L1: Interaural time delays are used for effective localization of _____-frequency sounds.

Answer 10

Low

Question 11

L1: Ototoxic medications often inhibit transduction channels of _______, which eventually kills them.

Answer 11

OHCs

Question 12

L1: Span of human hearing

Answer 12

20-20,000 Hz

Question 13

L1: The ____ of the cochlea responds best to high frequencies.

Answer 13

Base

Question 14

L1: The ____ of the cochlea responds best to low frequencies

Answer 14

Apex

Question 15

L1: The apex of the cochlea responds best to ______ frequencies.

Answer 15

Low

Question 16

L1: The base of the cochlea responds best to ______ frequencies.

Answer 16

High

Question 17

L1: The majority of hair cells in the cochlea are _______.

Answer 17

Outer hair cells

Question 18

L1: The primary auditory cortex is Brodmann area ___, and the secondary cortex including Wernicke’s area is Brodmann area ___.

Answer 18

41, 42

Question 19

L1: When the stereocilia bundle is displaced toward the longest stereocilia, _______ is elicited.

Answer 19

depolarization

Question 20

L1: When the stereocilia bundle is displaced toward the shortest stereocilia, _______ is elicited.

Answer 20

hyperpolarization

Question 21

L2: _____ is a localization mechanism that relies on phase-locking.

Answer 21

Interaural time delays

Question 22

L2: ______ neurons sense frequency and intensity and provide efferent innervation to OHCs.

Answer 22

Medial Olivocochlear (MOC)

Question 23

L2: _______ encoded in the dorsal cochlear nucleus is useful for elevation localization.

Answer 23

Monoaural spectral shape

Question 24

L2: ________: creation of sounds by evoked or spontaneous movements of OHCs that set the basilar membrane in motion; used to test newborn hearing

Answer 24

Otoacoustic emissions

Question 25

L2: _______: a ____-rich fluid that fills the scala media

Answer 25

endolymph; potassium

Question 26

L2: At the level of the _______, neurons are encoding auditory information for the contralateral ear.

Answer 26

inferior colliculus

Question 27

L2: Cochlear amplifier: displacement of the ______ by the ____.

Answer 27

basilar membrane; OHCs

Question 28

L2: Decussated DCN and VCN cells regroup in the ________ and ascend to the _______.

Answer 28

Lateral lemniscus; inferior colliculus

Question 29

L2: Dorsal cochlear neurons decussate via the _______.

Answer 29

Dorsal acoustic stria

Question 30

L2: Downward movement of the ________ compresses fluid in the ________, which causes an outward bulging of the round window;

Answer 30

basilar membrane; scala tympani

Question 31

L2: Inferior colliculus neurons innervate the _______.

Answer 31

Ipsilateral Medial Geniculate Nucleus, Contralateral Medial Geniculate Nucleus, Contralateral inferior colliculus

Question 32

L2: Interaural level differences are processed in the ______.

Answer 32

Lateral superior olive

Question 33

L2: Interaural time delays are processed in the _______.

Answer 33

Medial superior olive

Question 34

L2: Lateral superior olive neurons project to the _______ and _______.

Answer 34

ipsilateral dorsal nucleus of the lateral lemniscus (DNLL), ispsilateral inferior colliculus

Question 35

L2: Mechanisms of overcoming acoustic impedance mismatch (2)

Answer 35

Area of stapes foot, levering action of incus/malleus

Question 36

L2: Medial superior olive neurons send excitatory afferents to the ____ and ______.

Answer 36

ipsilateral dorsal nucleus of the lateral lemniscus (DNLL), ispsilateral inferior colliculus

Question 37

L2: MTNB neurons are ____-ergic, providing ______ input on the lateral superior olive.

Answer 37

glycin; inhibitory

Question 38

L2: Regions of the auditory cortex are connected via the ______ and _______.

Answer 38

association fibers, anterior commissure

Question 39

L2: The _______ pumps potassium ions into the scala media to maintain an endocochlear potential of _____.

Answer 39

stria vascularis; +80 mV

Question 40

L2: The basal end of the hair cell is bathed in a fluid called ______.

Answer 40

perilymph

Question 41

L2: The lateral superior olive receives ipsilateral input from the ______.

Answer 41

Anteroventral cochlear nucleus

Question 42

L2: The medial geniculate nucleus sends axons to the _______, located in the _______.

Answer 42

Primary auditory cortex (A1); superior temporal gyrus

Question 43

L2: Ventral cochlear neurons decussate via the _______.

Answer 43

Trapezoid body

Question 44

L2: When the stapes is pressed on the _______, the fluid in the ________ is compressed

Answer 44

oval window; scala vestibuli

Question 45

L3: ____ of ANFs are myelinated and innervate _______. (Type ___

Answer 45

95%; IHCs; I

Question 46

L3: ____ of ANFs are unmyelinated and innervate ______. (Type __)

Answer 46

5%; OHCs; II

Question 47

L3: ANFs have cell bodies in the _______ and innervate the ______ and _______.

Answer 47

Spiral ganglion; dorsal cochlear nucleus, ventral cochlear nucleus

Question 48

L3: The inferior colliculus receives auditory fibers from the ______ and ______.

Answer 48

Cochlear nuclei, pontine nuclei (superior olivary complex)

Question 49

L3: The lateral superior olive receives contralateral input from the ______.

Answer 49

Medial nucleus of the trapezoid body (MNTB) from the AVCN