(week10) Perception- Hearing

Question 1

what is a pressure wave

Answer 1

vibrations of molecules of medium e.g. air

Question 2

what are the 3 main auditory percepts

Answer 2

loudness- sound wave pressure level
pitch- sound wave frequency
timbre- sound wave shape

Question 3

what are decibels (dB)

Answer 3

a physical measure of sound amplitude or sound pressure level

Question 4

how is percieved loudness measured

Answer 4

by comapring 2 tones and deciding which one sounded louder (phons).
varies with sound frequency

Question 5

what is frequency (Hz)

Answer 5

a physical measure of sound oscillation rate (1 Hz= 1 oscillation per sec)

Question 6

the same sensation of pitch can be elicted by different sounds TRUE or FALSE

Answer 6

true

Question 7

what is timbre

Answer 7

when a listener can judge that 2 sounds, similarly presented and same loudness and pitch, are different

Question 8

what are harmonics in the auditory system

Answer 8

frequencies that interger multiples of the fundamental frequency

Question 9

what are the two structures of the outer ear

Answer 9

pinna and concha

Question 10

what does the outer ear do

Answer 10

-gather sound energy and focus it via the auditory meatus on the tympanic membrane (eardrum)
- selectively filter sound frequncies to provide cues about source elevation

Question 11

what does the middle ear play a role in

Answer 11

impedance matching

Question 12

what is an ossicle in the ear

Answer 12

a very small bone in the ear

Question 13

how many ossicles does the middle ear have

Answer 13

3- malleus, incus, and stapes

Question 14

what does the inner ear contain

Answer 14

the cochlea (coiled structure with fluid-filled chambers)

Question 15

what happens in the inner ear

Answer 15

pressure waves are transformed into neural signals

Question 16

what is the fluid in the cochlea called

Answer 16

perilymph

Question 17

what is the organ of corti in the ear

Answer 17

a sensory organ that runs along the whole basilar membrane.
It contains hair cells with stereocilia (transducers that convert motion into neuronal signals)
It is the start of the auditory nerve

Question 18

what is the basilar membrane in the ear

Answer 18

a fibrous structure within the cochlea that vibrates in response to sound waves, forming the base of the organ corti

Question 19

what are stereocilia in the corti organ

Answer 19

transducers that convert motion into neuronal signals

Question 20

what are inner hair cells in the ear

Answer 20

the sensory receptors that send info to higher cerebral levels.
make u-p majority of fibres in auditory nerve

Question 21

what do outer hair cells do in the ear

Answer 21

recieve projections from upper cerebral levels. they play a role in active filtering

Question 22

what is mechano-electrical transduction in auditory nerve fibres

Answer 22

a mechanical tension which opens K+ leading to action potentials in auditory nerve fibres

Question 23

what is phase locking in the auditory system

Answer 23

each auditory nerve fibre is tuned to a best frequency

Question 24

what are the mechanical proporties of the basilar membrane

Answer 24

narrow and stiff at base but wide and flexible at the apex

Question 25

are different parts of the basilar membrane tuned to different frequencies

Answer 25

yes

Question 26

what is the decomposition of frequencies along the basilar membrane

Answer 26

high frequencies at the base and low frequencies at the apex

Question 27

what is tonotopic organisation

Answer 27

spatial arangment of how the auditory system processes sound frequencies

Question 28

what is the place model of pitch perception

Answer 28

zone of maximum excitation on basilar membrane

Question 29

what is the rate model of pitch perception

Answer 29

precise timing of individual spikes (micro-sec range)

Question 30

what does the perceptual system use a combination of

Answer 30

the place model and the rate model