auditory

Question 1

what range do we hear?

Answer 1

20-20,000 Hz

Question 2

what does wavelength refer to?

Answer 2

pitch

Question 3

what does amplitude refer to?

Answer 3

loudness

Question 4

what does waveform refer to?

Answer 4

tone / timbre

Question 5

where is the pinna & what does the pinna of the ear do?

Answer 5

pinna: outer ear
changes frequencies, learn between sound behind vs infront of us

Question 6

cochlea
(feature and why)

Answer 6

fluid filled, allowing for a high impedence of sound (compared to air)

Question 7

how can you describe movement of the ossicles?

Answer 7

small movements, high pressure
allowing for more effective transmission

Question 8

organ of corti

Answer 8

transducer of the auditory system

Question 9

inner hair cells

Answer 9

sensory transduction of sound
via cilia that sticks out

Question 10

outer hair cells

Answer 10

(not transducing)
supplied by efferent nerves
contractile allow stiffening between basilar membrane & tectorial membrane to filter how much energy will be experienced
modulators via alt. how much activation occurs

Question 11

cilia of inner vs outer hair cells

Answer 11

inner are arranged messier (being embedded in gelatinous membrane) and outer hair cells are in neat chevrons

Question 12

hair cell mechanics

Answer 12

cilia form bundles @ different heights, when they move they move as a bunch

Question 13

@ base of basilar membrane?

Answer 13

short, thick fibres
high frequency

Question 14

@ apex of basilar membrane?

Answer 14

long, thin fibres
low frequency

Question 15

shearing force

Answer 15

two membranes move at different pivot points
shearing force on hair cells, make them get bent @ deflection of basilar membrane

Question 16

tectorial membrane movement

Answer 16

moves side to side

Question 17

basilar membrane movement

Answer 17

up and down

Question 18

mechanoelectrical transduction via hair cells

Answer 18

high potassium in scala media, therefore inward gradient into cell = depolarisation = Ca2+ influx = NT release activating afferent nerve receptors
via mechanically gated K+ channels

Question 19

scala media vs scala tympani ion concentrations

Answer 19

media: high K+ low Na+
tympani: low K+ high Na+

Question 20

how do you encode frequency?

Answer 20

where its coming from on the basilar membrane

Question 21

auditory pathway to brain

Answer 21

spiral ganglion - auditory nerve - superior olive (brainstem) - medial geniculate (thalamus) - primary auditory cortex

Question 22

how do we detect location of sound?

Answer 22

inter-aural time difference
detect difference in time for sound to reach, allocating location to plane space

Question 23

cortical territory (what is it + 2 features)

Answer 23

different frequencies at different place on basilar membrane
unevenly magnified (more interest in speech) & plastic