Special Sensory (Hearing)

Question 1

What kind of medium does sound waves need to vibrate?

Answer 1

-air

Question 2

What does frequency measure? Units?

Answer 2

• cycles per second

- Hz

Question 3

Define pitch

Answer 3

-tone that a frequency waves produces

Question 4

What are the characteristics of a high frequency wave?

Answer 4

• Higher pitch

- more waves (shorter periods between waves)

Question 5

What are the characteristics of a low frequency wave?

Answer 5

• lower pitch

- less waves ( longer periods between waves)

Question 6

How is the sound wave intensity measured? (Units?)

Answer 6

• wave amplitude (dB)

- higher energy= higher amplitude)

Question 7

What is the path of sound through the ear?

Answer 7

1) tympanic membrane
2) Malleus, incus, stapes
3) Stapes vibrates oval window, creates fluid waves within the cochlea
4) Fluid pushes flexible membranes of the cochlear duct. Hair cells bend and ion channels open creating an electrical signal that alters neurotransmitter release
5) neurotransmitter release onto sensory neurons that create actions potentials that travel through the cochlear nerve to the brain
6) . Energy from the waves transfers across the cochlear duct into the tympanic duct and is dissipated back into the middle ear at the round window

Question 8

Pitch is discriminated in what ways? (2)

Answer 8

• Low and high

Question 9

Coding for pitch is the function of what structure?

Answer 9

• basilar membrane

- has variable sensitivity to sound wave frequencies along its length

Question 10

Where does sound distort on the basilar membrane from a low pitch sound?

Answer 10

• near the apex of cochlea

- flexible region

Question 11

Where does sound distort on the basilar membrane from a high pitch sound?

Answer 11

• base of cochlea

- stiff region near round window

Question 12

How is loudness determined?

Answer 12

• an increase in noise will increase the action potential firing in the cochlear nerve

Question 13

What are the 3 hearing pathologies mentioned in class?

Answer 13

• Conductive deafness
• sensorineural deafness
• central deafness

Question 14

What are the characteristics of conductive hearing loss?

Answer 14

• occurs when sound waves do not reach the inner ear

Question 15

What are the characteristics of sensorineural hearing loss?

Answer 15

• damage to inner ear structures (cochlea, hair cells)

- sound waves are not processed correctly

Question 16

What are the characteristics of central deafness?

Answer 16

-damage to neural pathway