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Flashcards in Cochlear Mechanics Deck (15)
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1
Q

In what direction does a rarefaction deflect the basilar membrane?

A

-Upward

2
Q

In what direction does a rarefaction open the ion channels at the end of the stereocilia?

A

-Laterally

3
Q

Tip links do what for stereocilia?

A
  • Strengthen the structure

- Open/close ion channels in stereocilia

4
Q

Why does the traveling wave goes from base to apex?

A

-Travels from a stiffness-limited region to mass-limited region

5
Q

The tuning on the basilar membrane is improved by what?

A

-Active cochlear potentials, which add energy to the basal slope of the TW

6
Q

How does the basilar membrane tuning of a zombie compare to an alive person?

A

-Broader

7
Q

How does the sensitivity of a zombie compare to an alive person?

A

-Poorer

8
Q

How long does the traveling wave take to go from base to apex in a human?

A

-10 ms

9
Q

How does the tuning at the basilar membrane change with level?

A

-Broader tuning occurs at high intensity levels

10
Q

What are on the axes of a tuning curve?

A
  • X axis: BM amplitude (dB)

- Y axis: Stimulus frequency (Hz)

11
Q

What frequencies show linear basilar membrane input-output functions?

A

-Off-frequencies away from the CF

12
Q

Why were von Bekesy’s original Nobel prize winning measurements questioned?

A
  • Subjects were dead, which is problematic if tuning is metabolic-dependent
  • Stimuli needed to be presented at ~130 dB to get a response, which would not be feasible to replicate in live subjects due to cochlear damage
  • Poor/broad tuning could not explain frequency selectivity in perception
13
Q

How does the tuning curve of a hearing impaired person compared to a typical hearing person?

A
  • Broader

- Poor frequency selectivity

14
Q

Does the amplitude of the traveling wave grow or diminish as it travels down the cochlear duct? Why?

A
  • Grows

- When the same amount of energy passes from a dense region to less dense reason, TW will increase in amplitude

15
Q

After reaching the resonance point, how fast does the traveling wave dissipate? Why?

A
  • Extremely quickly

- Reaches a mass-limited region whose nature makes wave motion impossible