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**SLP Audiology > Tympanometry > Flashcards

Flashcards in Tympanometry Deck (48)
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1
Q

What is tympanometry

A

a test of integrity of the TM and middle ear function

2
Q

what are the three main measures of tympanometry?

A
  • tympanogram
  • acoustic reflexes
  • other: reflex delay, ET function
3
Q

What is immitance?

A

a measure of how readily a system can be set into motion by a driving force

4
Q

What is admittance/ compliance?

A

the ease with which energy will flow through a vibrating system

5
Q

What is impedance?

A

the extent to which a system resists the flow of energy though it

6
Q

What three factors determine the impedance of system? which one is the most important?

A
  • stiffness **most important
  • resistance
  • mass
7
Q

If the ear has high compliance this means that there is _______ sound bouncing back to the ear

A

minimal

8
Q

T or F the ear drum vibrates most efficiently when pressure is equal on both sides

A

true

9
Q

As pressure displaces the TM from rest what three things happen?

A
  • decrease in vibratory efficiency
  • decrease in energy flow
  • increase in sound bouncing back
10
Q

What does a tympanogram measure

A

it measures changes in compliance as a function of air pressure changes in the ear canal

11
Q

On a tympanogram, as compliance increases, sound ______

A

decreases

12
Q

Describe a Type A tympanogram

A

point of greatest compliance is at 0 daPa (-100 to 100 daPa) and compliance is normal

13
Q

Describe a Type As tympanogram

A

pressure is normal, but compliance is low so the peak is not as big

14
Q

Describe a Type AD tympanogram

A

pressure is normal, but compliance is high so the peak is larger

15
Q

Who has a Type A tympanogram

A
  • people with normal hearing

- people with sensorineural hearing loss

16
Q

Describe a Type B tympanogram

A

there is no point of greatest compliance, it is a flat tympanogram

17
Q

Who has a Type B tympanogram

A
  • People with conductive hearing loss
  • People with advanced otosclerosis
  • People with fluid in their middle ear
  • People with perforated ear drum or PE tubes
  • Could also be caused from a blocked probe
18
Q

Describe a Type C tympanogram

A

the point of maximum compliance occurs when negative pressure is in the ear canal, so pressure in the middle ear must be negative (less than -100 daPa)

19
Q

We don’t normally see hearing loss until the negative middle ear pressure reaches _____ daPa

A

-150

20
Q

Who would have a Type C tympanogram?

A
  • People with ET dysfunction
  • If you have a cold
  • If you just got off of an airplane
  • Pressure from large adenoids or tonsils
21
Q

Kids with negative middle ear pressure will often return with ______ in middle ear space due to effusion

A

fluid

22
Q

What are the two important things to look at when reading a tympanogram?

A
  • pressure at the peak

- height of the peak (compliance)

23
Q

What is the range of normal compliance values?

A

.30 - 1.70 cm3

24
Q

If you have a compliance value smaller than the normal range, it means that the ear has ________ than normal mobility

A

less

25
Q

If you have a compliance value larger than the normal range, it means that the ear has ________ than normal mobility

A

greater

26
Q

The first step in a tympanogram is figuring out the compliance of the outer ear. How do we do this?

A
  • Immobilize the eardrum with positive pressure (+200 daPa)
  • There is a large amount of sound returned to the probe, this helps us determine the volume of the outer ear in cm3 which represents the compliance of the outer ear
27
Q

The second step in a tympanogram is figuring out the compliance of the outer ear and middle ear together. How do we do this?

A
  • Decrease the pressure in the EAM until the TM reaches maximum compliance
  • Increased mobility allows more energy to be admitted by middle ear, there is decreased sound coming back to the probe
28
Q

What is involved in the third step of a tympanogram?

A

-We take the measurement of the outer ear + the middle ear and we subtract out the outer ear to find the compliance of the middle ear only

29
Q

What is typical ear canal volume?

A

between 0.6 - 2.0cm3 with ear difference less than or equal to 2cm

30
Q

With a Type B temp and a normal ECV the lesion is likely where?

A

middle ear space

31
Q

With a Type B temp and a high ECV the lesion is likely where?

A

tympanic membrane (perforation)

32
Q

With a Type B temp and a low ECV the lesion is likely where?

A
  • outer ear canal
  • clogged probe
  • probe against wall
33
Q

Predict the tymp type for someone with microtia

A

Type A

34
Q

Predict the tymp type for someone with a middle ear tumour

A

Type B

35
Q

Predict the tymp type for someone with an incompletely formed cochlea

A

Type A - there is no impairment in the outer or middle ear

36
Q

Predict the tymp type for someone with a marble stuck in the EAM

A

Type B

37
Q

Predict the tymp type for someone with inflamed tonsils and adenoids

A

Type C

38
Q

Predict the tymp type for someone with a large TM perforation

A

Type B

39
Q

Predict the tymp type for someone with noise-induced hearing loss

A

Type A (noise-induced HL is typically sensorineural)

40
Q

What is the acoustic reflex?

A

a stiffening of the middle ear in response to intense sounds

41
Q

The acoustic reflex is frequency specific, to what frequencies?

A

500-4000Hz

42
Q

The acoustic reflect may be absent if there is damage in the auditory pathway below the _______

A

superior olive

43
Q

What is an ipsilateral acoustic reflex?

A

present a signal to one ear and detect a decrease in TM compliance (increase in stiffness and sound bouncing of TM) in that ear

44
Q

What is a contralateral acoustic reflex?

A

present a signal to one ear and detect a decrease in TM

compliance in the opposite ear

45
Q

T or F the acoustic reflex typically occurs unilaterally

A

F - it occurs bilaterally

46
Q

What level of dB HL elicits the acoustic reflex?

A

less than or equal to 100 dB HL

47
Q

People with what type of temps demonstrate a acoustic reflex?

A
  • measured with Type A
  • never with type B
  • seldom with type c
48
Q

What are the 3 small tubes within the metal probe on the tympanometer?

A

1) air pump
2) tone generator
3) mic