Lecture 13 - Structure and function of the auditory system

Question 1

which type of waves are sound waves?

Answer 1

longitudinal

Question 2

what is the relation of frequency to length of sound wave?

Answer 2

inversely related

Question 3

what does fundamental frequency (f0) correspond to in sound?

Answer 3

the repitition rate/pitch of the sound

Question 4

harmonics are integer multiples of what?

Answer 4

fundamental frequency

Question 5

what is sound intensity measured in?

Answer 5

decibels

Question 6

in a spectogram what do lighter areas represent?

Answer 6

more energy/power

Question 7

is sound intensity a log scale?

Answer 7

yes

Question 8

what are the main 2 components of the outer ear and what is their main function?

Answer 8

pinna and ear canal, collect and focus sound waves

Question 9

what are the main 2 components of the middle ear and what is their main function?

Answer 9

tympanic membrane and ossicles, transmit vibrations to the cochlea

Question 10

what is the main component of the inner ear and what is its main 2 functions regarding its 2 types of hair cells?

Answer 10

cochlea

outer hair cells amplify vibrations and inner hair cells tranduce mechanical vibrations to electrical nerve signals

Question 11

name the 3 ossicles of the middle ear

Answer 11

malleus, incus, stapes

Question 12

what connects the cochlea to the foot of stapes?

Answer 12

oval window of cochlea

Question 13

travelling waves on the basilar membrane displace the……… as the basilar membrane is …..

Answer 13

organ of corti, fluid

Question 14

where are high frequency waves decoded on the basilar membrane? where are low frequency waves decoded?

Answer 14

high = base
low = apex

Question 15

in which section of the ear is the ear drum located?

Answer 15

middle ear

Question 16

which type of cochlear hair cells actively move which in turn amplifies membrane vibrations? what does this do to the sensitivity of the other type of cochlear hair cells?

Answer 16

outer hair cells, enhances sensitivity of inner hair cells

Question 17

which type of cochlear hair cells Get sound into the brain and are Displaced passively by vibrations?

Answer 17

inner hair cells

Question 18

otoacoustic emissions (OAEs) measure the activity of which type of cochlear hair cells doing what?

Answer 18

outer hair cells causing physical vibrations, propagating thwm back to the tympanic membrane and into the air

Question 19

name the 2 types of otoacoustic emissions

Answer 19

spontaneous (s) and sound evoked (te and dp)

Question 20

what is a useful clinical test of cochlear health in some situations?

Answer 20

otoacoustic emissions using sensitive microphones

Question 21

what is the range of frequency detection for humans?

Answer 21

20 - 20,000 Hz

Question 22

does an input from 1 cochlea reach one or both sides of the brain?

Answer 22

both

Question 23

name the 5 stages of the ascending auditory pathway

Answer 23

cochlear nuclei (dCN, vCN)
superior olivary complex
inferior colliculus
medial geniculate body
auditory cortex

Question 24

where in the brain is the medial genicuate body found (ascending auditory pathway)?

Answer 24

thalamus

Question 25

which structure in the ascending auditory pathway receives early bilateral input? which stage of the pathway is it?

Answer 25

superior olivary complex, 2nd

Question 26

name the 2 types of auditory nerve fibres

Answer 26

low spontaneous rate and high spontaneous rate

Question 27

which auditory nerve fibre type has a high threshold for activation, is used to being occasionally active and is needed for signal in noise processing?

Answer 27

low spontaneous rate

Question 28

which auditory nerve fibre type has a Low threshold for activation, is Used to being active for long periods, is Necessary for hearing quiet sounds in quiet environments and forms the Basis of pure tone audiogram (hearing test)?

Answer 28

high spontaneous rate

Question 29

give the correct name for a hearing test

Answer 29

pure tone audiogram

Question 30

the descending auditory pathway has …… connections than the ascending, has ……. function, mediates …… attention and auditory ……

Answer 30

more, inhibitory, selective, prediction

Question 31

which axis is processed mainly by the superior olivary complex for determining the location of sounds?

Answer 31

left to right axis (azimuth)

Question 32

which axis is much less accurate and has head/pinna related transfer function in determining the location of sounds?

Answer 32

the front/back and top/bottom

Question 33

name the gyrus found in the primary auditory cortex? which fissure is it tucked away in?

Answer 33

heschel’s gyrus, sylvian fissure

Question 34

in which two locations of the brain does the non-primary auditory cortex exist?

Answer 34

superior temporal gyrus and planum temporale

Question 35

in which brain hemisphere is there temporal processing in speech?

Answer 35

left

Question 36

in which brain hemisphere is there pitch processing?

Answer 36

right

Question 37

subcortical auditory electrical brain responses are known as what?

Answer 37

ABRs

Question 38

cortical auditory electrical brain responses are known as what?

Answer 38

event related potentials (ERP)

Question 39

which type of auditory brain response is typically elicited by repetitive clicks and is the main basis of hearing assessment in infants?

Answer 39

subcortical ABRs

Question 40

how would you describe the organisation of the auditory pathway?

Answer 40

tonotopically organised