chapter 4.3

Question 1

what is the function of the ear?

Answer 1

to gather sound waves and transform them in to neural signals

Question 2

what is the function of hearing?

Answer 2

to extract some sort of meaning from those sound waves to inform you about the nature of the sound source

Question 3

what are sound waves?

Answer 3

changes in mechanical pressure transmitted through solids, liquids or gasses

Question 4

what are the 2 important characteristics of sound waves?

Answer 4

frequency
amplitude

Question 5

what is frequency of sound waves?

Answer 5

refers to wavelength and is measured in hertz, the number of cycles a sound wave travels per second

Question 6

what is pitch?

Answer 6

the perceptual experience of frequencies

Question 7

what kind of sound waves do high frequency and low frequency sounds have?

Answer 7

high frequency sounds have short wavelengths and a high pitch

low frequency sounds have long wavelengths and a low pitch

Question 8

what is amplitude of a sound wave?

Answer 8

determines its loudness

Question 9

what is the range humans can detect sounds in?

Answer 9

20 Hz - 20,000 Hz

Question 10

how much greater can mice hear than humans?

Answer 10

they can hear 5 times greater than humans but have difficulty hearing lower frequencies that we can easily detect

Question 11

what is the pinna?

Answer 11

the outer region that helps channel waves to the ear and allow you to determinate source or location of a sound

Question 12

what is the auditory canal?

Answer 12

a tube extending from the pinna to the eardrum

Question 13

what causes the eardrum to vibrate?

Answer 13

sound waves

Question 14

what are the 3 tiny movable bones that make up the ossicles (middle ear)?

Answer 14

the malleus (hammer
incus (anvil)
stapes (stirrup)

Question 15

what do the ossicles attach to?

Answer 15

an inner ear structure called the cochlea

Question 16

what is the cochlea?

Answer 16

a fluid filled membrane that is coiled in a snail like shape and contains the structures that convert sound into neural impulses

Question 17

what does a hearing aid do?

Answer 17

it amplifies the colours of sounds so that they can be detected by a damaged auditory system

Question 18

if hearing aids do not work, what might someone do?

Answer 18

they may require cochlear implants, small electronic devices that bypass the damaged areas of the ear and instead directorate the auditory nerve

Question 19

what is sound localization?

Answer 19

the process of identifying where sound comes from

Question 20

what part of the body handles sound localization?

Answer 20

parts of the brain stem as well as by a midbrain structure called the inferior colliculus

Question 21

what are the 2 ways we localize sound?

Answer 21

we take advantage of the slight different between a sound hitting both ears to estimate the direction of the source

we localize sound by using differences in intensity in which sound is heard by both ears, you will hear more intensely in what ear is on the side the noise is coming

Question 22

what is sound shadow?

Answer 22

a phenomena where we notice differences in intensity in which sound is heard by both ears

Question 23

what is the place theory of hearing?

Answer 23

the idea that we perceive pitch based on the location along the basilar membrane that the sound stimulates

Question 24

what is the frequency theory?

Answer 24

another idea that we perceive pitch depending on the frequency the basilar membrane vibrates

Question 25

how much does a 70 Hz sound stimulate the hair cells in the basilar membrane?

Answer 25

about 70 times per second

Question 26

what is the upper limit of out hearing?

Answer 26

our neuerons can’t be stimulated more than 1000 times per second

Question 27

how can we hear sounds higher than 1000 Hz if one neauron cannot be stimulated more than 1000 timer per second?

Answer 27

because groups of neuron’s fire in rapid succession, this is called the “volley principle”

Question 28

what is the primary auditory cortex?

Answer 28

a major perceptual centre of the brain involved in perceiving what we hear

Question 29

what does the second auditory cortex do?

Answer 29

it helps us to interpret complex sounds, including those found in speech and music

Question 30

are we born with a fully developed auditory cortex?

Answer 30

no we must learn to analyze different patterns of sounds

Question 31

what is the timeline of growth of the auditory cortex?

Answer 31

less than 3 mo: can detect simple pitch changes

4-6 mo: can detect silence gaps in tone

8 mo: can localize sound

12 mo: the auditory system becomes specialized to its culture, but cannot recognize sound patterns that aren’t in its own language or culture

Question 32

how can we perceive music?

Answer 32

we can perceive the differences in the pitch

Question 33

where is the primary auditory cortex?

Answer 33

the temporal lobes

Question 34

what hemisphere is sensitive to pitch with brain damaged patients?

Answer 34

the auditory cortices in the right hemisphere

Question 35

what controls our sense of balance?

Answer 35

our vestibular system

Question 36

what is our vestibular system?

Answer 36

a sensory system in the ear that provides information about spatial orientation of the head as well as head motion

Question 37

what are the 2 structures the vestibular system contains?

Answer 37

vestibular sacs
semicircular canals

Question 38

what are the vestibular sacs?

Answer 38

structures that influence your ability to detect when tour head is no longer in an upright position

Question 39

what is the semicircular canals?

Answer 39

three fluid-filled canals found in the inner ear that respond when your head moves in different directions

Question 40

what does the constant flow of information about the head form the semicircular canal help us with?

Answer 40

to keep our head upright and maintain our balance

Question 41

when we panic when we lean to far back in a chair, why is that?

Answer 41

due to the fact that the vestibular nuclei in the brain stem influence activity of the nervous system as well as the amygdala

Question 42

why do you feel sickness when trying to read in a car?

Answer 42

because the inconstancy in the visual and vestibular system, the visual input (words on page) are not moving but your vestibular system is sending signals to your brain that your body is in a moving car