Hearing continued

Question 1

stereocilia cause changes in ____ ________ as they are flexed

Answer 1

graded potentials

Question 2

______ in response to sound results in neurotransmitter release to auditory nerve

Answer 2

depolarization

Question 3

depolarization is the opposite of photoreceptors that __________ when exposed to light

Answer 3

hyperpolarize

Question 4

responses of individual AN fibers to different frequencies are related to their place along the cochlear partition is called

Answer 4

place coding

Question 5

clearest when sounds are very faint is called

Answer 5

frequency selectivity

Question 6

what is the name for a graph plotting thresholds of a neuron or fiber in response to sine waves with varying frequencies at the lowest intensity that will give rise to a response

Answer 6

threshold tuning curve

Question 7

what happens to specificity of AN fibers at high amplitudes?

Answer 7

they get washed out/muddied

Question 8

all AN fibers synapse to the _____ _____ for the ___ ___ ___

Answer 8

cochlear nuclei; same side ear

Question 9

cells in the cochlear nuclei can code for … and use _____ _______

Answer 9

sound onset for particular frequencies or sets of frequencies; lateral inhibition

Question 10

where are two places that we have learned about that use lateral inhibition?

Answer 10

horizontal cells in the eyes

cochlear nuclei

Question 11

superior olives

Answer 11

first place auditory information from both ears meets

Question 12

which system receives information first from both eyes/ears: auditory or visual?

Answer 12

auditory

Question 13

inferior colliculus

Answer 13

receives input from both ears, but stronger signal from contralateral ear

Question 14

order of places information received in sound

Answer 14

1. cochlear nucleus
2. superior olive
3. inferior colliculus
4. MGN
5. Auditory cortex

Question 15

MGN

Answer 15

part of thalamus

frequency-based, tonotopic organization maintained at all levels even into cortex

Question 16

primary auditory cortex (A1)

Answer 16

first part of cortex to respond to sound, relatively basic processing of any sound

much like V1

Question 17

Secondary and associational auditory areas (belt and parabelt)

Answer 17

respond to more complex sounds

parabelt communicates w/ other senses

Question 18

tonotopic description of auditory cortex

Answer 18

sorted on frequency

the more anterior = lower

the more posterior = higher

Question 19

psychoacoustics

Answer 19

psychophysical study of how auditory information impacts perception of sound (and thus the auditory system)

Question 20

audibility threshold

Answer 20

the lowest sound pressure level that can be reliably detected at a given frequency

remember: 50% threshold

Question 21

equal-loudness curve

Answer 21

a graph plotting sound pressure level vs. the frequency for which a listener perceives constant loudness (JND)

2 sounds that sound almost identical in loudness @ different frequencies/amplitudes

Question 22

_______ and _______ have an impact on loudness, proven by equal loudness curve

Answer 22

frequency; amplitude

Question 23

temporal integration

Answer 23

longer sounds of the same amplitude will seem louder than shorter ones (in the range of 100-200 ms)

Question 24

can we detect a pitch change from 1000 to 1001 Hz?

Answer 24

yes!

Question 25

masking

Answer 25

where a 2nd sound is played on top of another 2nd sound usually white noise mask needs to be higher in amplitude than tone to drown it out

Question 26

white noise

Answer 26

all wavelengths of sound at once bandwidth of 20-20,000 Hz

Question 27

critical bandwidth

Answer 27

increasing the bandwidth further no longer affects the tone

Question 28

role of the ear canal

Answer 28

transmit sound

Question 29

blocking the ear canal will ...

Answer 29

impact how sound can be transmitted

Question 30

conductive hearing loss

Answer 30

found in middle ear caused by issue with ossicles (can grow too large for example in otosclerosis)

Question 31

sensorineural hearing loss

Answer 31

caused by deficits in cochlea and/or auditory nerve, usually due to hair cell damage most common form of hearing loss, caused by excessive loud noise, infections, and drugs

Question 32

presbycusis

Answer 32

age-related hearing loss

Question 33

which gender sees more hearing loss with age?

Answer 33

men

Question 34

interaural time differences (ITD)

Answer 34

tiny differences in timing between when the sound hits each ear measured in microseconds

Question 35

negative degrees of hearing means ...

Answer 35

coming from the left

Question 35

azimuth

Answer 35

angle of sound on horizontal plane relative to head

Question 36

best detection of smallest just noticeable difference is @ _____ Hz

Answer 36

1000

Question 37

positive degrees of hearing means ....

Answer 37

coming from the right

Question 38

ITD detection is ______ dependent

Answer 38

frequency

Question 39

where are the cells that are in our brain that process these timing differences from each ear?

Answer 39

medial superior olive (MSO)

Question 40

for the medial superior olive, think medial --> _______

Answer 40

microseconds/time

Question 41

2 theories on medial superior olive and ITDS

Answer 41

there are differences in the length of their axons to various cells, meaning their signals exacerbate timing differences or signal travels slightly further in one ear than the other down the cochlea, making slight difference in frequency

Question 42

interaural level difference (ILD)

Answer 42

intensity of sound to each ear heavily impacted by your head

Question 43

an increase of frequency = ________ in the interaural level difference

Answer 43

increase

Question 44

lateral superior olive (LSO)

Answer 44

gets excitatory inputs from ipsilateral (same) ear and inhibitory from contralateral (opposite) ear think lateral = level/loudness

Question 45

"cone of confusion"

Answer 45

a lot of locations will have similar ILDs/ITDs

Question 46

directional transfer function

Answer 46

your pinna, ear canal, etc. change the intensity of sounds with different frequencies when they arrive at each ear from different locations in space

Question 47

your brain knows your pinna and uses its reflection of sound to ...

Answer 47

understand location and elevation

Question 48

inverse-square law for distance perception

Answer 48

as distance increases, intensity decreases faster

Question 49

spectral composition of sound

Answer 49

higher frequencies decrease in energy more than lower frequencies as sound travels over distance

Question 50

why can people who are blind hear better?

Answer 50

visual cortex can "remap" to process auditory information in the absence of visual inputs

Question 51

in vision, the first part of the brain with cells that receive information from both eyes is in _____, while in hearing the first part is in _____. a. LGN; MGN b. V1, A1 c. V1, Superior Olive d. LGN, superior olive

Answer 51

c

Question 52

An 1800 Hz tone is masked on Trial 1 with noise that has a bandwidth of 1750-1850 Hz. The tone is just barely audible at this point. What would happen if the bandwidth of noise was widened to 1500-2100 Hz? Assume amplitude is never adjusted for either sound. a) The tone would become clearer against the irrelevant bandwidths b) The tone would not be affected by the increasing bandwidth, as 100 Hz is generally the critical bandwidth c) The tone would become inaudible, as increasing bandwidth in this range generally mask overlapping tones d) The tone would be audible, but it would sound like it was at a different frequency

Answer 52

c

Question 53

A sound produces a maximal Interaural Timing Difference but almost no Interaural Level Difference. Which of the following most likely would produce that? a) A sound at 90 degrees at 6000Hz b) A sound at 180 degrees at 6000Hz c) A sound at 180 degrees at 200 Hz d) A sound at 90 degrees at 200 Hz

Answer 53

d