Chapter 12 Flashcards Preview

Sensation and Perception > Chapter 12 > Flashcards

Flashcards in Chapter 12 Deck (31):
1

auditory space

exists all around wherever there is sound

2

auditory localization

locating sound sources in auditory space

3

location cues

information that tells us where sounds are coming from using info from the way the sound interacts with our head and ears

4

two location cue types

binaural cues (2 ears)

monaural cues (1)

5

3 dimensions of sound localization

azimuth (left-right)

elevation (up-down)

distance (sound source from listener)

6

2 binaural cues

interaural time difference (ITD)

interaural level difference (ILD)

7

interaural time difference

difference between when a sound reaches left ear and when it reaches right

 

ITD becomes larger as a source is more located to one side

8

interaural level difference

difference in sound pressure level reaching each ear

9

acoustic shadow

the head is a barrier for sound

reduces the intensity of sounds that reach the far ear

10

what kinds of sounds does ILD occur for

 

why

only high frequency sounds

 

waves are closer together and more easily disrupted by the head

11

cone of confusion

the many areas in space where ILD and ITD are the same

12

monaural cue for sound localization

spectral cue

13

spectral cue

the distribution of frequencies that reach the ear associated with specific locations

 

The sound interacts with the head and pinnae to give us this info

14

indirect vs. direct sounds

direct - sound going right to your ears

indirect - sound reaching your ears after bouncing off objects

15

Which cues work better with which coordinates?

binaural - azimuth

spectral - elevation

16

Auditory pathway

auditory nerve

cochlear nucleus

superior olivary nucleus (brain stem)

inferior colliculus (midbrain)

medial geniculate nucleus (thalamus)

auditory cortex

17

where do sounds from both ears first "meet"?

superior olivary nucleus

18

What 3 places can signals go once they reach A1 

core area: A1 plus some surrounding area

belt area: surounds core

parabelt area

19

Jeffress model of auditory localization

each neuron is wired to receive signals from both ears and where they meet along the neuron determines location

20

coincidence detectors

neurons in jeffress model

these fire when signals from both ears reach the neuron at the same time

different detectors fire at different ITD values

21

ITD tuning curves

plot a neuron's firing rate against ITD

22

What are ITD tuning curves like in mammals?

 

What does this suggest about coding?

Broad

 

Based on broadly tuned neurons in each hemisphere corresponding to each ear - location of sound is determined by ratio of response

23

What kind of code is the broad code for mammals?

distributed code

24

What cortical area gives more precise localization info than A1 neurons?

neurons in belt

25

Describe the what pathway for sound

from anterior core/belt area to prefrontal cortex

identifying sounds

26

Describe where pathway for sound

posterior of core/belt to prefrontal cortex

locating sounds

27

simple vs. complex sounds in cortex

A1 activated by simple sounds

Anterior belt by complex

28

precedence effect

we will perceive sounds as coming from the source that reaches are ears first (if time between the two is short enough)

29

What happens to delays as a room gets bigger

they get longer

30

ventriloquism effect

also called?

visual capture

when sounds come from one place appear to come from another place

31

two-flash illusion

when a single flash is accompanied by two tones and we perceive two flashes