chapter 10-hearing in the environment

Question 1

large portion of processing is done ___ A1

Answer 1

before

Question 2

differences in structure of auditory and visual systems from

Answer 2

evolutionary reasons, subcortical vs cortical

Question 3

primary auditory cortex is mapped

Answer 3

tonotopically

Question 4

primary auditory cortex

Answer 4

A1; 1st area within temporal lobes of brain responsible for processing acoustic information; tones, frequencies

Question 5

belt area

Answer 5

adjacent to A1 with inputs where neurons respond to more complex characteristics of sounds, change in frequency over time

Question 6

parabelt area

Answer 6

lateral and adjacent to belt area, complex sounds and integration across senses

Question 7

what

Answer 7

temporal lobe (hearing and vision); identification and interpretation of sound

Question 8

where

Answer 8

subcortical-superior olive; location

Question 9

monaural pathway in the inferior colliculi may carry info about

Answer 9

what the sound is

Question 10

binaural responses in the superior olive contains special neural circuits that computes ___ a sound originates

Answer 10

where

Question 11

Monaural pathway

Answer 11

single ear processing to the superior colliculus, tone based, nature of the sound itself

Question 12

MGN is like the

Answer 12

LGN

Question 13

binaural reponses

Answer 13

location; comparison across 2 different ears; superior olive

Question 14

how do you locate a sound

Answer 14

sound enters ears the same regardless of location; will be closer to one ear than the other

Question 15

interaural time differences (ITD)

Answer 15

the difference in time between a sound arriving at one ear versus the other

Question 16

azimuth

Answer 16

the angle of a sound source on the horizon relative to a point in the center of the head between the ears

Question 17

azimuth is measure in ___, with 0 being ___ and 180 being ___

Answer 17

degrees, straight ahead, directly behind

Question 18

azimuth angle is __ to the right and ___ to the left

Answer 18

positive, negative

Question 19

if sound comes from directly in front of or behind someone LTD’s are ____

Answer 19

absent

Question 20

LTD’s are greatest when

Answer 20

coming from one side to the other

Question 21

size of circles is due to

Answer 21

temporal difference in location of sound

Question 22

time unit of ITD

Answer 22

microseconds

Question 23

threshold of ITD

Answer 23

~10-20 microseconds

Question 24

ITD with what aspect of sound

Answer 24

phase

Question 25

interaural level difference (ILD)

Answer 25

the difference in level (intensity) between a sound arriving at one ear versus the other

Question 26

for frequencies greater than 1000 Hz, the head block some of the energy reaching the ___ ear

Answer 26

opposite

Question 27

ILD is largest where; and nonexistent where

Answer 27

largest at 90 and -90; none at 0 and 180

Question 28

ILD generally correlated with ___ of sound source, but not the same as ITD

Answer 28

angle;due to frequency, irregular shape of the head

Question 29

level

Answer 29

amplitude

Question 30

ILD remains ___ for low frequencies; __ correlation

Answer 30

constant; low

Question 31

high frequency, __ correlation

Answer 31

high

Question 32

low frequency sounds use

Answer 32

ITD for best info

Question 33

high frequency sounds use

Answer 33

both ILD and ITD

Question 34

phase

Answer 34

precise timing

Question 35

superior olive

Answer 35

relay station in the brain stem where inputs from both ears come together; MSO and LSO; where llocation info is processed

Question 36

medial superior olive

Answer 36

ITDs

Question 37

lateral superior olive

Answer 37

ILDs; excitatory from ipsilateral and inhibitory from contralateral ear; sum across

Question 38

cone of confusion

Answer 38

region of positioins in space where all sounds produce the same ITDs and ILDs; problem of ambiguous info

Question 39

to solve the cone of confusion problem

Answer 39

turn head to disambiguate ILD/ITD similarity

Question 40

HRTF (head related transfer function)

Answer 40

filtering properties of our hed and ear; specific to individual; no physical movement, experience

Question 41

echolocation

Answer 41

using the returned/reflected sound that was produced by the observed in order to determine location and shape of objects in the world; gives 3D info of the world to blind person and they process it in the visual system

Question 42

sound localization uses

Answer 42

auditory distance perception

Question 43

simplest cue for auditory distance perception

Answer 43

relative intensity of sound; sounds are less intense with greater distance

Question 44

inverse-square law

Answer 44

as distance from a source increases, intensity decreases faster such that decrease in intensity is the distance squared; best within 1 meter of head

Question 45

spectral composition of sounds

Answer 45

higher frequencies decrease in energy more than lower frequencies as sound waves travel from source to one ear

Question 46

relative amounts of direct energy vs reverberant energy

Answer 46

reverberant-more auditory copies the further you are away

Question 47

harmonics

Answer 47

complex sounds have more than 1 frequency

Question 48

fundamental frequency

Answer 48

lowest frequency of harmonic spectrum

Question 49

missing fundamental effect

Answer 49

the pitch listeners hear corresponds to the fundamental frequency, even if it is missing

Question 50

lowest level fundamental aspect fill info

Answer 50

in

Question 51

if you have a sound and sum together, the output of summation has a

Answer 51

peak at 4 ms

Question 52

timbre

Answer 52

psychological sensation by which a listener can judge that two sounds with the same fundamental loudness and pitch are dissimilar

Question 53

in natural situation

Answer 53

acoustic environment is busy and has multiple sound sources

Question 54

source segregation (auditory scene analysis)

Answer 54

processing an auditory scene consisting of multiple sources into separate sound images; gestalt grouping by similarity and proximity

Question 55

source segregation; what

Answer 55

frequency content/timbre; similarity

Question 56

source segregation; where

Answer 56

location of the sound source; proximity

Question 57

grouping by timbre

Answer 57

tones that have increasing and decreasing frequencies will group either by pitch or timbre

Question 58

grouping by onset

Answer 58

when sounds being at the same time, they appear to be coming from the same sound sound

Question 59

how do we know that listeners really hear a sound as continuous

Answer 59

principle of good continuation

Question 60

principle of good continuation

Answer 60

in spite of interruptions, one can still “hear” a sound

Question 61

behavioral evidence for principle of good continuation

Answer 61

can’t tell if sound glide is present or not; brain fills in missing info if blocked by noise

Question 62

physiological evidence for principle of good continuation

Answer 62

A1 metabolic activity consistent with perceived sounds, even if absent; single cell recordings in monkey same to real and restored tones

Question 63

restoration of complex sounds

Answer 63

listeners use “higher order” sources of info, not just auditory info to restore missing segment

Question 64

gaps in sound stream are ___ detrimental if filled with noise rather than silence

Answer 64

less

Question 65

with noisy gaps

Answer 65

cant even reliably tell where the gaps were specifically