audition

Question 0

wave of a pure tone can be described as a

Answer 0

sine wave

Question 1

sound?

Answer 1

vibration in the air that travels by pressure waves

Question 2

frequency

Answer 2

pitch
Hz
how many full waves in a second

Question 3

amplitude

Answer 3

loudness
dB
height of wave

Question 4

phase

Answer 4

timbre?
degrees
How far through the wave are we? timing/position

Question 5

what is a natural sound?

Answer 5

a collection of simple sine waves added together

Question 6

addition of 2 waves of same frequency, same amplitude and same phase =

Answer 6

sine wave

same frequency and phase but amplitude doubles

Question 7

complex wave =

Answer 7

adding 2 waves of different frequencies

Question 8

decomposing a complex sound into its sine wave components

Answer 8

fourier analysis

Question 9

in a complex wave what is the component with the lowest frequency that gives that note its characteristic pitch

Answer 9

fundamental

Question 10

peripheral auditory system

Answer 10

inner ear
middle ear
outer ear

Question 11

central auditory system

Answer 11

cells in the brainstem and cerebral cortex

Question 12

where is the organ of corti

Answer 12

along the basilar membrane

Question 13

pinna

Answer 13

flexible flap on the outside of ear

Question 14

meatus

Answer 14

external auditory canal, focuses sound waves into the ear

Question 15

component of middle ear

Answer 15

tympanic membrane (ear drum)
ossicles/bones

Question 16

auditory transduction

Answer 16

meatus focuses sound into the ear

• > tympanic membrane vibrates in response to sound
• > ossicles transmit energy from eardrum through cochlea
• > fluid displacement in cochlea causes vibration in basilar membrane
• > inner hair cells, in organ of corti, stimulate the auditory nerve
• > auditory nerve sends signal to the brain

Question 17

largest vibration near the stapes and base of the cochlea

Answer 17

high frequency

Question 18

largest vibration near the apex of cochlea

Answer 18

low frequencies

Question 19

auditory nerve cells filter….

Answer 19

on the basis of frequency.
e.g., band-pass filter

BASILAR MEMBRANE performs the filtering

Question 20

place code

‘frequency-to-place’

Answer 20

hair cells have a ‘characteristic frequency’ that they are ‘tuned’ to.
determined by where they are on the basilar membrane

Question 21

how does our ear cover the full dynamic range of human hearing?

Answer 21

2 groups of auditory fibres with different roles

high spontaneous rate fibres = lower sound intensities
low spontaneous rate fibres = higher intensities

Question 22

cortical organisation for audition

Answer 22

tonotopic organisation.

primary auditory cortex is organised in terms of sound frequency

Question 23

role of outer hair cells in the cochlea

Answer 23

amplify and fine tune the repsonses of the inner hair cells

feedback mechanism

Question 24

motile response

Answer 24

when outer hair cells change their size in response to impulses from higher areas

Question 25

3 major theories of pitch perception

Answer 25

place theory pattern theory timing theory

Question 26

place theory

Answer 26

frequency to place conversion of the basilar membrane * place coding best for high freq simple tones but doesn't account for missing fundamentals (if its missing it can't go through a filter)

Question 27

bandwidth

Answer 27

= RANGE of freqs that are transduced by this filter

Question 28

wide abndwidth

Answer 28

= broad tuning | predicts poor ability to discriminate between frequencies

Question 29

narrow bandwidth

Answer 29

sharp tuning | good frequency discrimination

Question 30

masking

Answer 30

= noise. | need more intense signal to reach detection threshold

Question 31

timing theory

Answer 31

timing of neural impulses carries frequency info (beats) if fundamental not present our brain 'fits it in' ONLY possible for low-freq sounds

Question 32

pattern theory

Answer 32

depends on resolved harmonics, finds the BEST FITTING harmonic series. best with low frequencies

Question 33

how is loudness measured?

Answer 33

matching and scaling tasks

Question 34

loudness =

Answer 34

intensity of firing

Question 35

excitation pattern model

Answer 35

overall loudness is proportional to the neural activity evoked by it in the auditory nerve.

Question 36

monaural sound localisation

Answer 36

echoes resolve vertical localisation; PINNAE play a role | coming from up or down?

Question 37

binaural sound localisation

Answer 37

horizontal localisation; interaural time difference interaural level difference

Question 38

interaural time difference

Answer 38

difference in time of arrival depends on AZIMUTH (horizontal plane) processed in MEDIAL SUPERIOR OLIVE

Question 39

interaural level difference

Answer 39

difference in intensity level depends on frequency (low freq; diff small, high freq; diff large) processed in LATERAL SUPERIOR OLIVE

Question 40

if low freq which binaural sound localisation tool is used?

Answer 40

itd

Question 41

if high freq which binaural sound localisation tool is used?

Answer 41

ild

Question 42

cone of confusion

Answer 42

2 possible azimuths (front of behind) | solve; move head to introduce level and time differences

Question 43

precedence effect

Answer 43

apparent sound source direction is determined by the earliest sound to arrive at the ear

Question 44

complex waves must have

Answer 44

2 waves of diff frequencies

Question 45

tectorial membrane

Answer 45

flexible structure lying on top of the basilar membrane

Question 46

where in the ear does impedence mathching

Answer 46

inner ear

Question 47

displacement of cochlear hair cells toward the taller stereocillia __________ the cell

Answer 47

despolarizes

Question 48

tonotopic organisation

Answer 48

high freq largest vibration at stapes and base of cochlea | low freq largest vibration near apex of cochlea

Question 49

linear filter

Answer 49

does not add components that were not present in the input

Question 50

impedence matching

Answer 50

matches up the differing acoustic impedences of air and inner-ear fluid

Question 51

phase locking

Answer 51

firing of hair cells/neural impulses in synchrony with the variation of pressure of the input sound

Question 52

residue pitch

Answer 52

pitch heard in a complex wave due to BEATS rather then to resolvable harmonics

Question 53

freq discrimination is best for....

Answer 53

low frequencies

Question 54

ohm's law

Answer 54

the auditory system constructs a separate representation for each frequency compoenet of a complex sound

Question 55

missing fundamental is in a ________

Answer 55

complex tone

Question 56

beats from unresolved harmonics, same as fundamental | known as...

Answer 56

residue pitch

Question 57

pattern theory can't explain.....

Answer 57

residue pitch from unresolved harmonics

Question 58

place theory best explain

Answer 58

high freq pure tones

Question 59

timing theory best for

Answer 59

low frequency pure tones

Question 60

how is loudness matching acheived?

Answer 60

participant matches the intensity of a sound. if the procedure is used for a range of comparison frequencies (to invesitigate frequency depndence of loudness) an EQUAL-LOUDNESS CONTOUR is produced

Question 61

loudness scaling

Answer 61

participants are asked to assign numbers to sounds at different intensities

Question 62

like other sensory modalities, loudness does NOT increase..

Answer 62

linearly with intensity

Question 63

duplex theory

Answer 63

ITD & ILD