auditory perception - final exam

Question 1

sound transformation up the auditory pathway

Answer 1

sound waves begin as vibrations in the air

enter ear canal

move through various stages

converted into neural signals in the brain

Question 2

air bone fluid

Answer 2

air = sound waves

bone = ossicular vibrations

fluid - BM waves

Question 3

outer ear

Answer 3

filters the sound

air

Question 4

ear canal resonance

Answer 4

the resonance of the ear canal = the resonance of the vocal tract

amplifies the resonant freqs of speech

Question 5

threshold of audibility

Answer 5

softest sound that can be heard

varies w/ freq

“0 loudness”

Question 6

equal loudness curve

Answer 6

different freqs need varying sound pressures to be perceived as equally loud

low & high freq sounds need greater amp to be heard at same loudness as mid freq sounds

Question 7

linear scale of auditory representation

Answer 7

measure freqs uniformly

Hz

Question 8

nonlinear scale of auditory representation

Answer 8

reflect human perception

smaller changes in lower freqs are more noticable than in higher freqs (stretch it out @ lower freqs, condense @ higher freqs)

Bark
cochlea

Question 9

freq masking

Answer 9

each neuron responds to multiple freqs

if already firing to 1 freq (1000Hz)
can’t increase firing much to another (1100Hz)

Question 10

neural saturation

Answer 10

where high sound intensities cause neurons to max out

restricting dynamic range & clarity in hearing

sounds that follow other sounds don’t get as big of a neural response
neurons need time to rest

Question 11

stages up the auditory pathway

Answer 11

sound waves enter outer ear

travels through ear canal & strikes the ear drum

vibrations transferred to ossicles in the middle ear

vibrations enter cochlea where hair cells convert them to electrical signals

signals travel through the AN to the brain

Question 12

upward spread of masking

Answer 12

sounds are more easily masked when they are higher in freq than the masker

low freqs travel farther along the BM, therefore moving more of the BM

high freqs don’t vibrate as much of the BM so are not able to mask lower freqs

the traveling wave loses its energy after it hits the characteristic place - doesn’t vibrate beyond that

Question 13

where along a freq scale are changes in pitch more audible

Answer 13

lower freqs (100-500Hz)

due to Bark’s nonlinear structure -
reflecting our sensitivity to pitch vibrations in that range