Cochlear Dead Regions

Question 1

cochlear dead regions happen from

Answer 1

loss of IHCs

Question 2

off frequency listening

Answer 2

a tone is heard away from the region of the peak basilar membrane vibration
ex: if you have dead region at 8,000 - if intensity is great enough of the sound, maybe the 7,000 Hz will respond

Question 3

Contrast “on-frequency” listening with “off-frequency” listening in terms of basilar membrane vibration and perception. Explain how tones are perceived in a healthy basilar membrane as compared to a cochlea with dead regions.

Answer 3

they are perceived at the best frequency and in dr respond on the edges of where that region is (perception is occurring at upper or lower frequencies)

perception happens at adjacent frequencies

Question 4

on frequency hearing

Answer 4

happens at the point of max displacement

Question 5

off frequency hearing

Answer 5

takes place at a place other than the point of max displacement

Question 6

what happens if low levels of masking noise are applied?

Answer 6

will tell us which region was responding
if we apply noise, will not interfere with threshold if coming from on frequency but will if it is coming from off frequency

Question 7

TEN

Answer 7

threshold equalizing noise

Question 8

what is ten test

Answer 8

a broadband noise
Spectrally shaped so the masked threshold is approximately the same in dB HL for frequencies between 250Hz to 10 kHz

Question 9

What does the current dead region research show?

Answer 9

1/3 (3%) of people show evidence of dead regions

Question 10

Dead regions are usually present at what?

Answer 10

greater than 55dB HL