Chapter 12-Sound localization and Organization

Question 1

Define auditory space

Answer 1

We perceive objects and events to happen in positions depending solely on sound- very similar to how we perceive visual space

Question 2

Define auditory localization

Answer 2

We can localize an objects position in space based on sound

Question 3

What are the three dimensions used to identify sound localization?

Answer 3

Azimuth
Elevation
Distance

Question 4

Define Azimuth

Answer 4

The horizontal meridian that is measured in degrees to assist in finding the distance between the listener and object
is used when turning your head- side to side motion

Question 5

Define Elevation

Answer 5

The vertical meridian measured in degrees to assist in finding the distance between the listener and the object

is used by moving head up and down-> nodding

Question 6

Distance

Answer 6

the difference in space between the listener and object

Question 7

When is the azimuth and elevation equal to 0 degrees?

Answer 7

When the viewer is looking straight ahead

Question 8

Where are humans best at localizing sound?

Answer 8

When the sound is directly in front of them

Question 9

What is the primary receptor of sound?

Answer 9

The cochlea

Question 10

What is the role of the cochlea?

Answer 10

to detect sound frequencies

Question 11

What does the auditory system use to localize sound?

Answer 11

Location cues

Question 12

What are location cues?

Answer 12

The auditory version of depth cues
are both binaural and monaural cues

Question 13

What do Binaural cues detect?

Answer 13

Interaural time difference and interaural level differences

Question 14

What do monaural cues detect?

Answer 14

Head and pinnae shape

Question 15

What does ITD stand for?

Answer 15

Interaural Time Difference?

Question 16

What is the interaural time difference when sound approaches from straight ahead of a person?

Answer 16

Because the sound will arrive at each ear at the same time the ITD will be 0

Question 17

What is the interaural time difference when sound approaches from one side of a person?

Answer 17

Because it will take the sound longer to reach one ear than the other the ITD will be greater than 0

Question 18

What is ITD referred to when there are continuous sounds?

Answer 18

Interaural phase difference

Question 19

Why can we only detect phase differences in long wavelengths (lower frequencies) and not shorter wavelengths (higher pitch)

Answer 19

The wavelengths must be long enough to reach both ears

Question 20

What does ILD stand for?

Answer 20

Interaural Level Difference

Question 21

Define an acoustic shadow

Answer 21

the barrier our heads create to reduce the intensity of sounds reaching our far ear

Question 22

When does the acoustic shadow not work?

Answer 22

When the soundwave is wider than the head- aprox. 1000-2000 hz

Question 23

Which dimension relies on ITD and ILD

Answer 23

Azimuth

Question 24

Which frequencies does ITD rely on

Answer 24

low frequencies between 20-1000Hz

Question 25

Which binaural cue dominates?

Answer 25

Interaural time difference

Question 25

Which binaural cue dominates?

Answer 25

Interaural time difference

Question 26

Why is ITD used more than ILD

Answer 26

ITD is used more frequently because most sounds occur between 20 and 1000hz

Question 27

Are binaural cues useful for elevation?

Answer 27

no

Question 28

Why do we only need on pinae to make sense of monaural cues?

Answer 28

We only need one pinae to make sense of monaural cues because constructive and destructive interference aid us in finding the elevation of sound

Question 29

Which is associated with elevation; monaural or binaural cues?

Answer 29

Monaural cues are associated with elevation

Question 30

Interaction with what body parts change the characteristics of sound?

Answer 30

Head and pinae

Question 31

what is constructive and destructive interference dependent on?

Answer 31

the incoming angle of the soundwave relative to the head and pinnae

Question 32

why is it called the spectral cue

Answer 32

Depending on the position of the soundwave entering the ear the frequency will increase or decrease--> therefore the frequency lands on a spectrum

Question 33

Does the spectral cue affect the azimuth or the elevation?

Answer 33

elevation

Question 34

Who has broader ITD neurons? Barn owls, or gerbils?

Answer 34

Gerbils

Question 35

What is the order of structures in the central auditory processing system

Answer 35

Cochlear nucleus Superior olivary nucleus Inferior colliculus Medial geniculate nucleus

Question 36

What is an acronym for the central auditory processing system?

Answer 36

COCK SONIC MG--> a very fast car

Question 37

Where does binaural processing start?

Answer 37

Superior olivary nucleus

Question 38

Breakdown the acronym for the structures in the central auditory processing system

Answer 38

COCK--> Cochlear nucleus SON--> Superior olivary nucleus IC--> Inferior colliculus MG--> Medial geniculate nucleus

Question 39

Identify where the ventral stream for the auditory system is in the brain

Answer 39

located in the anterior portion of the belt threads through the temporal and prefrontal cortex

Question 40

What is the function of the ventral stream in the auditory system

Answer 40

The 'what' stream identifies sound

Question 41

Identify where the dorsal stream for the auditory system is in the brain

Answer 41

Originates at the posterior belt and is strung to the parietal and prefrontal cortices

Question 42

What is the function of the dorsal stream in the auditory system?

Answer 42

The where--> therefore finding where sound is coming from

Question 43

Describe cryoloop activation

Answer 43

Cooling areas of the brain to cause temporary inactivation- acts as a temporary lesion

Question 44

What is a key difference in the visual and auditory systems receptive fields?

Answer 44

Receptive field location is DIRECTED in vision, whereas in hearing the receptive field location is calculated.

Question 45

Define direct sounds

Answer 45

Sound waves directly coming from the source to your ear- more likely to experience indoors

Question 46

Define indirect sounds

Answer 46

Sound Waves bouncing off objects between the source and your ear- more likely to experience outside

Question 47

What is the precedence effect?

Answer 47

Our ability to locate sounds is not affected by indirect sounds. However, indirect sounds will affect our perception of sound quality

Question 48

Define echo threshold

Answer 48

When there is a delay between direct and indirect sound we will hear an echo

Question 49

What affects echo threshold?

Answer 49

when lag sound is quieter than the lead sound and sounds with longer durations such as speech and music

Question 50

What is our perception of sound based on?

Answer 50

sound produced at the source How sounds are reflected before they reach our ears

Question 51

What field is concerned with the study of how sounds are reflected in rooms and the practical application for auditory psychophysics?

Answer 51

Architectural acoustics

Question 52

What do acoustic engineers do?

Answer 52

design concert halls that have favorable acoustical properties compared to a subset of subjective prototypes

Question 53

What effect does absorption have on sound waves?

Answer 53

Lots of absorption=few reflected soundwaves and little indirect sound Little absorption=MANY reflected sound waves and lots of indirect sound

Question 54

What effect does the design of the room have on soundwaves?

Answer 54

Room size affects the time it takes indirect sounds to reach the listener Room shape affects the direction reflected sound waves will be sent