chapter 10-hearing in the environment Flashcards Preview

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Flashcards in chapter 10-hearing in the environment Deck (65):
1

large portion of processing is done ___ A1

before

2

differences in structure of auditory and visual systems from

evolutionary reasons, subcortical vs cortical

3

primary auditory cortex is mapped

tonotopically

4

primary auditory cortex

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

5

belt area

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

6

parabelt area

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

7

what

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

8

where

subcortical-superior olive; location

9

monaural pathway in the inferior colliculi may carry info about

what the sound is

10

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

where

11

Monaural pathway

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

12

MGN is like the

LGN

13

binaural reponses

location; comparison across 2 different ears; superior olive

14

how do you locate a sound

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

15

interaural time differences (ITD)

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

16

azimuth

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

17

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

degrees, straight ahead, directly behind

18

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

positive, negative

19

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

absent

20

LTD's are greatest when

coming from one side to the other

21

size of circles is due to

temporal difference in location of sound

22

time unit of ITD

microseconds

23

threshold of ITD

~10-20 microseconds

24

ITD with what aspect of sound

phase

25

interaural level difference (ILD)

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

26

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

opposite

27

ILD is largest where; and nonexistent where

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

28

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

angle;due to frequency, irregular shape of the head

29

level

amplitude

30

ILD remains ___ for low frequencies; __ correlation

constant; low

31

high frequency, __ correlation

high

32

low frequency sounds use

ITD for best info

33

high frequency sounds use

both ILD and ITD

34

phase

precise timing

35

superior olive

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

36

medial superior olive

ITDs

37

lateral superior olive

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

38

cone of confusion

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

39

to solve the cone of confusion problem

turn head to disambiguate ILD/ITD similarity

40

HRTF (head related transfer function)

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

41

echolocation

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

42

sound localization uses

auditory distance perception

43

simplest cue for auditory distance perception

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

44

inverse-square law

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

45

spectral composition of sounds

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

46

relative amounts of direct energy vs reverberant energy

reverberant-more auditory copies the further you are away

47

harmonics

complex sounds have more than 1 frequency

48

fundamental frequency

lowest frequency of harmonic spectrum

49

missing fundamental effect

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

50

lowest level fundamental aspect fill info

in

51

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

peak at 4 ms

52

timbre

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

53

in natural situation

acoustic environment is busy and has multiple sound sources

54

source segregation (auditory scene analysis)

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

55

source segregation; what

frequency content/timbre; similarity

56

source segregation; where

location of the sound source; proximity

57

grouping by timbre

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

58

grouping by onset

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

59

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

principle of good continuation

60

principle of good continuation

in spite of interruptions, one can still "hear" a sound

61

behavioral evidence for principle of good continuation

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

62

physiological evidence for principle of good continuation

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

63

restoration of complex sounds

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

64

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

less

65

with noisy gaps

cant even reliably tell where the gaps were specifically