Lecture 4

Question 1

echo-location

Answer 1

helps to navigate through the world -> creating a 3D image

Question 2

people born blind

Answer 2

occipital lope adapts to use other senses
Neuroplasticity

Question 3

hearing is related to touch

Answer 3

touch =. sensitivity to pressure on the skin
hearing = sensitivity to pressure on a specific tissue of the ear

Question 4

What is sound?

Answer 4

the vibration of air produced by actions of an object
the vibrations move outwards from the sound source in a way that can describe as a wave

Question 5

amplitude

Answer 5

the height of the sound wave
indicates the pressure exerted by the molecules of air as they move back and forth
the loudness of sound

Question 6

frequency

Answer 6

the rate at which molecules of air move back and forth
the pitch, number of complete waves per second

Question 7

transformations

Answer 7

physical waves transform into electrical signals to be processed by any neurones

Question 8

sound has different qualities

Answer 8

evolution can therefore use sound in different ways

Question 9

evolution of sound

Answer 9

elephants use low frequency sounds for communications - sounds humans can’t detect

Question 10

individual differences

Answer 10

cognition isn’t a fixed concept
males 85 - 180 Hz and females 165 - 255 Hz

Question 11

outer ear

Answer 11

amplifier - acts as a funnel, receiving sound waves and sending them inwards
consist of the pinna, the flaps of skin and cartilage and the auditory canal, the opening in the ear
vibrations in the air, causes the air in the auditory canal to vibrate, which then causes the eardrum to vibrate

Question 12

middle ear

Answer 12

consist of three tiny bones and vibrations of the ear drum vibrate the bones which push against the oval window
amplifies the pressure of the received sound waves, so that transduction can occur

Question 13

the oval window

Answer 13

a smaller area than the ear drum, the pressure on it ossicles greater than the pressure received by the eardrum

Question 14

the inner ear

Answer 14

consists of the cochlea
contains the basilar membrane, which runs along the length of the cochlea
the basilar membrane is full of tiny hair cells. these hair cells, which act like touch receptors on the skin, connect to neurones whose axons form the auditory nerve
the auditory nerve transmits impulses to the brain areas responsible for hearing

Question 15

conduction deafness

Answer 15

amplification failures
occurs when the bones connected to the eardrum fail to transmit sounds to the cochlea
can be connected with surgery removing whatever is obstructing the bones movement
people with conduction deafness still hear their own voice because it is conducted through the skull bones to the cochlea, bypassing the middle ear

Question 16

nerve deafness

Answer 16

wear and tear
results from damage to the cochlea, hair cells, or auditory nerve
disease, heredity, and exposure to loud noises
hearing aids compensate for hearing loss, but only to some extent
in older adults, long term hearing loss can cause brain areas receiving certain frequencies to deteriorate due to inadequate input
lose the capacity to discriminate against different sound levels

Question 17

Bekesy

Answer 17

discovered how pitch is perceived
sound waves entering the cochlea set up ‘traveling waves’ on the membrane, from the nearest end towards the far ed

Question 18

high frequencies

Answer 18

produce waves that travel short distances

Question 19

low frequencies

Answer 19

produce waves that travel longer differences

Question 20

high pitch perception

Answer 20

firing neurones at the near end of the basilar membrane accompanied by little to no firing of neutrons at the far end

Question 21

low pitch perception

Answer 21

firing of neurones from the distant end of the basilar membrane

Question 22

asymmetry in auditory masking

Answer 22

the ability of one sound to prevent the hearing of another sound
low frequency sounds can mask high frequency sounds
the basilar membrane is sensitive to different frequencies at different parts

Question 23

loss of hearing as we get older

Answer 23

we lose sensitivity to high frequency sounds more than low frequency sounds
due to
wearing out of the hair cells with repeated use, especially when working in noisy environments

Question 24

why loss of hearing of high pitch sounds?

Answer 24

all sounds, high and low frequency, pass through the near end of the basilar membrane, which is sensitive to high frequency sounds. so the hair cell there wear out more than the cells further down the membrane

Question 25

pitch perfect

Answer 25

individual differences
some people can hear a sound an detect the pitch straight away

Question 26

different languages

Answer 26

‘tonal’ languages
different tones have different meanings
nurture

Question 27

hearing allows us to…

Answer 27

localise sounds
determine what is out there
communicate with other humans

Question 28

sound localisation

Answer 28

when we ‘hear’ the activity happens in our ears
but we perceive the sound as happening ‘out there’ and we can usually localise it

Question 29

cues for sounds localisation

Answer 29

inter aural time differences
inter aural intensity differences

Question 30

inter aural time differences

Answer 30

the time differences when sound waves reach one ear compared to the other
if a sound comes from straight ahead, the waves will reach both ears at the same time
but if the sound comes from, the right for example, the sound will reach the right ear a few fractions of a second earlier than the left ear

Question 31

inter aural intensity differences

Answer 31

sounds are more intense at the ear closest to the source of sounds, because the head blocks partially blocks the pressure waves from reaching the opposite ear
the head blocks high frequency sounds more effectively than low frequency sounds

Question 32

sound localisation

Answer 32

judging distance
as sound grows louder = perceive sounds as coming closer
two sounds differ in pitch = higher pitched frequencies carry better over further distances

Question 33

echos

Answer 33

reverberation is the only cue for absolute distance os the amount of reverberation
in a closed room, you first hear the sound waves the source and then the waves reflected off other objects
many echos = the sound is coming from far away
it is hard to localise sound sources in a noisy room where echos are harder to hear

Question 34

three directions we can judge sound location

Answer 34

left - right (azimuth)
distance
up - down (elevation)

Question 35

mono aural sound localisation cues

Answer 35

uses information from one ear
the pinna and the head affect the intensities of the frequencies

Question 36

auditory scene analysis

Answer 36

process by witch sound sources in the auditory scene are separated into individual perceptions

Question 37

heuristics help to perceptually organise stimuli

Answer 37

onset time - sounds that starts at different times are likely to come from different sources
location - a single sound source tends to come from one location and move continuously
similarity of timbre and pitch - similar sounds are grouped together

Question 38

phonemic restoration effect

Answer 38

the illusion whereby people hear phonemes that have been deleted, as if they were still there

Question 39

direct sound

Answer 39

sound that reaches the listeners ear straight from the source

Question 40

indirect sound

Answer 40

sound that is reflected off of environmental surfaces and then to the listener

Question 41

precedence effect

Answer 41

when there is a delay in sound, listeners hear the sounds as only coming from the louder speaker
we perceive the sounds as coming from the source that reaches our ears first