perception 5

Question 1

how do we localise sound?

Answer 1

binaural and monaural cues

Question 2

what is azimuth?

Answer 2

left right plane

Question 3

what is elevation?

Answer 3

up down plane

Question 4

what are binaural cues?

Answer 4

comparison of signals in left/right ears
signal location of sound in azimuth

Question 5

what are monaural cues?

Answer 5

work with one ear
localise the elevation and distance of sound

Question 6

what are interaural time differences?

Answer 6

relative time at which a sound arrives at the two ears

Question 7

what are interaural time differences affected by?

Answer 7

its location in azimuth
if straight ahead= distance to each ear is the same, no difference in time
if positioned to one side- reaches nearer ear first

Question 8

what does the range of interaural time differences depend on?

Answer 8

speed of sound
distance between the two ears

Question 9

what is the maximum interaural time difference for humans?

Answer 9

600us

Question 10

what do interaural time differences require?

Answer 10

precise signalling of timing

Question 11

what type of sounds are interaural time differences most useful for?

Answer 11

low frequency or abrupt onset sounds

Question 12

what are interaural level differences?

Answer 12

relative sound pressure reaching two ears depends on location of sound in azimuth

Question 13

why do interaural level differences impact a reduction in sound?

Answer 13

reduced sound for far ear due to head for high frequency sounds

Question 14

where does binaural processing begin?

Answer 14

within the brainstem in the superior olive

Question 15

what does the lateral superior olive contain?

Answer 15

neurons that are sensitive to ILDs

Question 16

what does the medial superior olive contain?

Answer 16

neurons that are sensitive to ITDs

Question 17

which binaural cue is best for low frequency sounds?

Answer 17

ITDs

Question 18

which binaural cue is best for high frequency sounds?

Answer 18

ILDs

Question 19

what are the limitations of binaural cues?

Answer 19

only provide ambiguous information about elevation
don’t tell us about distance
there are points which produce identical ITDs and ILDs= cone of confusion

Question 20

what are monaural localisation cues- elevation?

Answer 20

when sound reflects off the external ear(pinnae), the relative intensity of different frequency sound waves change with elevation
this is affected by individual’s ear shapes

Question 21

what are two monaural localisation cues for distance?

Answer 21

relative intensity
reverberation

Question 22

what is relative intensity?

Answer 22

sound intensity decreases with distance
further distance= weaker amplitude

Question 23

what is reverberation?

Answer 23

multiple reflections combine to produce a persistence of sound
sound reflecting off an object provides a cue for distance- as it alters the intensity and timing

Question 24

what is the precedence effect?

Answer 24

similar sounds arriving in quick succession from different locations are localised according to the direction of the first sound
for a short delay, only a single sound perceived

Question 25

what is auditory scene analysis?

Answer 25

need to segregate components of sound from different sources
need to group components coming from the same sound source

Question 26

what is spectral grouping?

Answer 26

combining different frequency sound components that occur at the same time
-if a sound has a different harmony will be heard separately
-frequency components that change together group together

Question 27

what is sequential grouping?

Answer 27

combining sequences of sound over time

Question 28

what is auditory stream segregation?

Answer 28

organising sounds over time into separate perceptual events

Question 29

what is sequential grouping: similarity of pitch?

Answer 29

sounds with similar pitch are often produced by the same source
increasing the frequency difference promotes stream segregation

Question 30

what is sequential grouping: temporal proximity?

Answer 30

sounds that occur in rapid progression tend to be produced by the same source
increasing presentation rate promotes stream segregation

Question 31

what is sequential grouping: similarity of timbre?

Answer 31

sound sources often have distinct tembre which provides a cue for stream segregation

Question 32

what is sequential grouping: continuity?

Answer 32

sounds that stay constant or change smoothly are often produced by the same source
perceived as continuous even when interrupted by noise

Question 33

what is phonemic restoration?

Answer 33

sequential grouping continuity can occur with speech as well as tones