Audition

Question 1

What are some important functions for hearing

Answer 1

1. Communication
2. Detect danger
3. Help

Question 2

What is sound

Answer 2

Variations in air pressure

Question 3

What is the difference between the speed of sound through air vs. through water

Answer 3

air 767mph (340m/s)

water 1500m/s

Question 4

What is a sounds wave

Answer 4

Alternating peeks and valleys of compressed air

Question 5

What are the variables in sound?

Answer 5

Frequency (pitch)

Intensity (loudness)

Question 6

What is the definition of frequency

Answer 6

The number of comprised air patches (Hertz)

-number of cycles/second

Question 7

What is the definition of Intensity

Answer 7

The difference in pressure between compressed air patches

-amplitude

Question 8

What is the human frequency range

Answer 8

20-20,000

Question 9

In which frequency range are we most sensitive to

Answer 9

2,000-4,000

which is speech range

Question 10

What is the difference between Hertz and Decibel

Answer 10

Hertz measured the pitch

Decible measures the loudness

Question 11

What is the minimum audibility curve

Answer 11

The minimum frequencies that are at a level for us to hear

Question 12

What are the 3 major divisions of the ear

Answer 12

1. Outer Ear
   - Auricle (Pinna)
   - Auditory canal
2. Middle Ear
   - Tympanic membrane
   - Ossicles
3. Inner Ear
   - Oval window
   - Cochlea

Question 13

What is the function of the auditory canal

Answer 13

To protect the ear drum

Enhances the intensities of sound by resonance

Question 14

What is the definition of resonance

Answer 14

A mechanism that enhances the intensity of certain frequencies because of the reflection of sound waves in a closed tube
-amplifies frequency depending on length and width of tube

Question 15

What are the 3 Ossicles

Answer 15

1. Malleus (hammer)
2. Incus (anvil)
3. Stapes (stirrup)

Question 16

What is the Eustachian (auditory) tube

Answer 16

An airway between the middle ear and the pharynx

-allows you to change the pressure in your ear

Question 17

What are the 3 reasons why the Ossicles necessary

Answer 17

1. Sound vibration is ineffective at moving fluid
2. Ossicles amplify the force exerted against the oval window
3. Ossicles convert air pressure changes to mechanical changes (causing fluid changes win the cochlea)

Question 18

What are the two windows of the cochlea

Answer 18

The oval window (in contact with stapes)

Round window

Question 19

What are the 3 ducts of the cochlea

Answer 19

1. Vestibular duct (separated by resigners membrane)
2. Cochlear duct (separated by basilar membrane)
3. Tympanic duct

Question 20

What are the 2 different fluids in the 3 chambers

Answer 20

1. Perilymph (Vestibular and tympanic duct, flows into each other)
2. Endolymph (Cochlear duct)

Question 21

Why is the basilar membrane important?

Answer 21

Contains the Organ of Croti

Question 22

What hangs over the organ of corti

Answer 22

The tectoral membrane

Question 23

What is the Helicotrema

Answer 23

A hole between the scala vestibule and scala tympani

at the very end of the unrolled cochlea

Question 24

How does sound move through the cochlea

Answer 24

Oval window> Scala Vestibuli> Helicotrema> Scala Tympani> Round Window

Question 25

What is the base of the basilar membrane

Answer 25

The base is thin and the membrane is thick

-high frequencies are encoded

Question 26

What is the apex of the basilar membrane

Answer 26

The apex is wide and the membrane is less rigid

-low frequencies are encoded

Question 27

What is the organ of corti

Answer 27

Lies on the basilar membrane and contains hair cells

The movement of the hair cess changes the activity of the hair cell

Question 28

What is the hair cell

Answer 28

Cells in the organ of corti in which when moved, the hair cells depolarize when the stereocilia bend

Tips of the stereocilia are in contact with the sectoral membrane.

Question 29

What are the 2 types of hair cells

Answer 29

Inner hair cells

Outer hair cells

Question 30

What are inner hair cells

Answer 30

Auditory receptor cells in the inner ear that are primarily responsible for auditory transduction and the perception of pitch
-only 5000 per ear

Question 31

What are outer hair cells

Answer 31

Auditory receptor cells in the inner ear that amplify the response of the inner hair cells
-more numerous

Question 32

What is motile response and how does it work

Answer 32

A response to sound of the outer hair cells in which the cells move

Cells tilt and get slightly longer, amplifies the basilar membrane vibration and amplify the response of the inner air cells

Question 33

How do signals get out of the cochlea

Answer 33

Hair cells synapse with spiral ganglion cells

-the axons of these neurons form the auditory portion of the Vestibulocochlear Nerve (cranial nerve 8)

Question 34

In which place in the brain does the sound from both ears come together

Answer 34

The Superior olives

Question 35

Where is the primary auditory cortex

Answer 35

On the superior temporal gyrus

Question 36

What kind of map is in the auditory cortex

Answer 36

Tonotopic map

-based on frequency lengths, shortest in the front and longer towards the back

Question 37

Why doesn’t the destruction of the auditory cortex in one hemisphere result in loss of hearing on one side

Answer 37

Because input from both ears goes to each hemisphere

Question 38

What does the destruction of the auditory cortex result in

Answer 38

A loss of the ability to localize sound in the opposite hemifield

Question 39

What is most hearing loss due to

Answer 39

Death or destruction of hair cells

-cant regenerate