sound localization

Question 1

spherical location dimensions

Answer 1

azimuth: horizontal
elevation: vertical
distance

Question 2

median plane

Answer 2

directly in front (0) or behind (180)

Question 3

which is more accurate : horizontal or vertical

Answer 3

we are better at localizing things in the horizontal

Question 4

types of cues

Answer 4

binaural cues and monaual cues

Question 5

binaural cues

Answer 5

location cues based on the comparison of the signals received by both ears
- provide information about the azimuth plane

Question 6

monaural cues

Answer 6

provide information about the elevation of the sound and resolve ambiguity in the binaural cues

Question 7

types of binaural cues

Answer 7

• ILD
• ITD

Question 8

ILD cues

Answer 8

the difference in sound level at the two ears
- comparisons help us localize
- biggest at direct sides
- better with high frequency

Question 9

causes of ILD

Answer 9

when sound is closer to one ear it will take longer to get to the otherand it will be quieter because it fades and because of the acoustic shadow
- difference in intensity is used by brain

Question 10

acoustic shadow

Answer 10

the head blocks the sound from reaching the farther ear
- it is more pronounced with higher frequencies

Question 11

interaural time difference (ITD)

Answer 11

the difference in time it takes for sound to hit each ear
- the closer hear gets sound bfore the farther one
- better with lower frequency

Question 12

where does ILD go

Answer 12

lateral superior olive (brainstem)

Question 13

where do ITDs go

Answer 13

medial superior olive (brainstem)

Question 14

cone of ambiguity

Answer 14

equally distanced sound sources are confused because they have similar ILDs and ITDs
- solved with head movements
- particularly for something right in front or behind

Question 15

spectral shape cue

Answer 15

a modification in sounds frequency spectrum caused by the pinna
- its helps give information about the elevation of a sound

Question 16

head-related transfer function

Answer 16

describes how sound waves are altered by the shape of the head, torso and outer ears
- unique
- helps us localize sound in space

Question 17

inverse square law

Answer 17

-as distance increases sound intensity decreases

Question 18

distanec cues

Answer 18

• inevrse square law
• reflected sound is farther away than direct sound

Question 19

doppler effect

Answer 19

sound moving towards you has a higher frequency than sound moving away

Question 20

auditory scene

Answer 20

• all of the sound entering the ears during the current interval of time

Question 21

auditory scene analysis

Answer 21

the process of separating and grouping sounds together among complex mixture of frequencies

Question 22

auditory stream

Answer 22

an assortment of frequencies that go together because they were emitted by the same source

Question 23

simultaneous grouping

Answer 23

• harmonic coherence
• synchrony or asynchrony

Question 24

sequential grouping

Answer 24

• frequency similarity
• temporal proximity

Question 25

perceptual completion of ocluded sounds

Answer 25

auditory system has good continuation and can continue sound when they are interrupted by others