the ear and sound

Question 1

what is the stimulus for hearing?

Answer 1

pressure waves / sound waves

Question 2

what do pressure waves represent a form of?

Answer 2

mechanical energy

Question 3

ears translate pressure energy ino?

Answer 3

neural code

Question 4

regardless of the barrier pressure waves are being transmitted through, we hear these waves that are created through

Answer 4

expansion and compression of the molecules

Question 5

what does frequency refer to?

Answer 5

the number of cycles per second

Question 6

what is frequency usually measured in?

Answer 6

hertz

Question 7

what is frequency related to?

Answer 7

the perceptual experience of pitch

Question 8

if there is a higher frequency, what length is the wavelength?

Answer 8

short

Question 9

what is amplitude?

Answer 9

the amount of compression and expansion of molecules in conducting medium

Question 10

what is amplitude related to?

Answer 10

perceptual experience of perceived loudness

Question 11

if something has a lower amplitude, the sound is?

Answer 11

quiet!

Question 12

what is amplitude measured in?

Answer 12

decibels (dB)

Question 13

what is the auditory system designed to do?

Answer 13

funnel in pressure (sound) waves and translate them into neural impulses for transduction

Question 14

what does the outer ear funnel sound towards?

Answer 14

the eardrum (tympanic membrane)

Question 15

what does the tympanic membrane do in response to incoming soundwaves?

Answer 15

the eardrum vibrates

Question 16

what does the middle ear consist of? what do they do?

Answer 16

three tiny bones that amplify the pressure waves relayed by the eardrum

Question 17

what are the three small bones in the middle ear?

Answer 17

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

Question 18

what is the malleus connected to? what does it form?

Answer 18

connected to the eardrum, which forms the boundary between the outer/middle ear

Question 19

what is the incus connected to?

Answer 19

the other two bones (malleus and stapes)

Question 20

what is the stapes connected to? what does it form?

Answer 20

connected to the oval window, which forms the boundary between the middle/inner ear

Question 21

what happens in the inner ear?

Answer 21

pressure waves actually become sound

Question 22

what are the three main parts of the inner ear?

Answer 22

cochlea, organ of corti, and basilar membrane

Question 23

what is the cochlea?

Answer 23

a fluid filled tube that moves when vibrations hit it

Question 24

what is the organ of corti?

Answer 24

within the cochlea that rests on the basilar membrane and contains hair cells that act as sound receptors

Question 25

vibrations from the oval window cause the fluid in the cochlea to move, which creates?

Answer 25

waves in the basilar membrane

Question 26

what do the sound waves do when they come into contacts with the hair cells?

Answer 26

these waves bend the hair cells, causing them to fire action potentials

Question 27

what does the hair cells form a synapse with?

Answer 27

the auditory nerve

Question 28

what are the steps of sound transduction as they go through each part of the ear?

Answer 28

1. outer ear: sound enters outer auditory canal and strikes the eardrum, causing eardrum to vibrate
2. middle ear: these vibrations cause the hammer, anvil and stirrup to vibrate and amplify the sound wave, which in turn vibrates the oval window
3. inner ear: these vibrations from the oval window cause the fluid inside the cochlea to move, movement of fluid bends the hair cells, causes neurotransmitter release in the auditory nerves they synapse with

Question 29

how is a high amplitude sound wave coded for?

Answer 29

higher amplitude sound waves bend hair cells more, resulting in a neurotransmitter release, resulting in a higher rate of firing

Question 30

how is loudness coded for?

Answer 30

as a function of both firing rate and identity of which neurons are firing

Question 31

what is frequency theory?

Answer 31

nerve impulses match the frequency of sound waves being coded

Question 32

what is a problem with frequency theory?

Answer 32

cannot explain the coding of higher frequencies that we can perceive

Question 33

what is place theory?

Answer 33

the specific place in the cochlea where a particular frequency of sound waves bends a hair cell most strongly will contribute to the coding of pitch

Question 34

what is our coding of pitch theory now?

Answer 34

low pitches are coded in accordance with frequency theory while high pitches are coded in accordance with place theory

Question 35

in the localization of sound, what is binaural hearing?

Answer 35

hearing with two ears

Question 36

how is the difference in arrival time between both ears informative?

Answer 36

sound arrives at the closer ear first which allows us to know where sound is coming from

Question 37

how is the difference in intensity between both ears informative?

Answer 37

the sound arriving at the closest ear is most intense

Question 38

how does conduction of deafness result?

Answer 38

from problems relating to the mechanical conduction of sound to the cochlea (middle ear is not working properly)

Question 39

would hearing aids be effective for conduction damage?

Answer 39

yes!