Immitance Intro

Question 1

What type of testing does immittance testing encompass?

Answer 1

Tympanometry

Ear canal volume measurement

Acoustic reflex testing
Acoustic reflex threshold
Acoustic reflex decay

Tests of Eustachian tube function

Question 2

What structures are assessed using immittance measures?

Answer 2

tymp middle ear
reflexes - effect on middle ear, auditory nerve, cochlea, b.s., facial nerve

Question 3

What are the components of an immittance meter?

Answer 3

probe signal (tone)
air pressure
microphone

Question 4

How is immittance testing conducted?

Answer 4

based on changing the pressure in the ear canal and measuring sound levels in the ear canal

Question 5

describes the flow of sound energy

Answer 5

immittance

Question 6

how much sound doesn’t get through the middle ear -

Answer 6

acoustic impedance

Question 7

how much sound does get through the middle ear -

Answer 7

acoustic admittance (height of the peak)/ compliance

Question 8

3 tubes (probe) = tymp

Answer 8

air pressure generator
microphone
tone generator

Question 9

how do you prepare the pt for a tymp?

Answer 9

Otoscopy first

Ask about ear-related symptoms
Discomfort, pain, drainage
Previous surgeries

Seat patient comfortably, instruct to remain still
Child may need to be gently restrained

Question 10

what is the probe tip

Answer 10

part that comes off - finding right size for patient - gets tight seal and couples to ear canal

Question 11

black only tube only generates just the tone

Answer 11

acoustic reflexes

Question 12

probe itself has 3 components

Answer 12

tone that is played when tymp is ran
microphone picks up sound in me space while running it
air pressure - changes air pressure

Question 13

explain the process of a tymp

Answer 13

sound goes into the ear, changes the pressure and measure the sound in the ear as the pressure changes by the microphone

Question 14

what is plotted on a tymp axis

Answer 14

x is pressure and y is admittance

Question 15

what can evaluate the middle ear function and identify middle ear disorders?

Answer 15

tympanometry
volume measures
Eustachian tube function measures

Question 16

what differentiates cochlear from retrocochlear

Answer 16

site-of-lesion testing
acoustic reflex thresholds
acoustic reflex decay

Question 17

do we expect a middle ear disorder with purely snhl?

Answer 17

no
abg shows it is conductve = middle ear
snhl = cochlear vs retrocochlear and no middle ear abnormalities

Question 18

what are tymp contradictions?

Answer 18

Complete stenosis or atresia

Otorrhea

Acute otitis media with red and bulging tm

Tenderness/soreness, otitis externa
In this case, test healthy ear and allow patient to judge
If proceed, let pt. know how to signal to stop test

Foreign bodies should be removed prior

Question 19

what is the right side of a tymp plot?

Answer 19

positive

Question 20

middle line on tymp?

Answer 20

line represents 0 (same atmosphere pressure as the room)

Question 21

left side of tymp plot?

Answer 21

left is negative
gives measurement in dcpascals
relative to the room

Question 22

what is the pressure in the ear canal the same as?

Answer 22

environment

Question 23

how can you manipulate pressure in the ear canal?

Answer 23

seal it off with probe tip

Question 24

explain what the peak of a tymp means

Answer 24

middle ear system operates the most effectively and letting the most sound through is the peak
other sides of peak is that sound is being opposed

Question 25

higher admittance

Answer 25

more sound is going through the middle ear floppy

Question 26

lower admittance

Answer 26

less sound stiffness in the system

Question 27

when does middle ear operate most efficiently?

Answer 27

ear canal and middle ear should be equal, when those are equal, middle ear operates the most efficiently peak means no neg middle ear pressure - et is working properly

Question 28

what tymp would we see if et is not ventilating the middle ear?

Answer 28

it is more negative peak shifts to the left - negative middle ear pressure, leading to fluid

Question 29

when would excessive cerumen contradict tymps?

Answer 29

Do not test if probe insertion will push against impacted cerumen Soft wax can damage probe Remove cerumen prior to tympanometry In some cases, tympanometry is performed when view of tm is obscured Do this only if deemed safe to do so!

Question 30

when should tymps be done with previous ear surgery

Answer 30

Not within 2 months of ear surgery unless formally approved and documented Reconstruction of ossicles or tm Only if given medical advice that it is safe If in doubt, ask medical advice

Question 31

P.E. tubes- to test or not to test?

Answer 31

This will vary depending on placement No sooner than within two weeks of placement, otherwise generally ok

Question 32

Pressure is continuously changed in the ear canal from _____ pressure to ______ pressure, relative to ambient pressure

Answer 32

negative, positive

Question 33

he most common probe tone

Answer 33

220/226 Hz

Question 34

probe tone for under 6 months

Answer 34

1,000 Hz

Question 35

pressure expressed in

Answer 35

daPa

Question 36

admittance expressed in

Answer 36

mmho or ml

Question 37

are mmho or ml equivalent?

Answer 37

yes refers to admittance

Question 38

how are tymps classified previouslY?

Answer 38

by shapes

Question 39

vary far negative peak

Answer 39

type c

Question 40

flat tymp

Answer 40

type b

Question 41

has the peak and falls within the box (norms) not to far high or low or left or right

Answer 41

type a

Question 42

very high peak (ossicular disarticulation)

Answer 42

a sub d

Question 43

shallow (stiffness/shallow)

Answer 43

a sub s

Question 44

point where middle ear system is operating most efficiently

Answer 44

peak pressure

Question 45

how close the peak is to 0

Answer 45

peak pressure

Question 46

what is the peak pressure norm for adults

Answer 46

+50 to -100 daPa

Question 47

what gives us an indication if there is neg pressure or not in the me

Answer 47

peak pressure

Question 48

approximates but does not measure middle ear pressure

Answer 48

peak

Question 49

what do we see if ET is not functioning (ETD)

Answer 49

Possible positive peak early stages of acute OM Negative peak

Question 50

Measures stiffness or “floppiness” of the ossicular chain/middle ear system

Answer 50

static admittance

Question 51

Frequently referred to as compliance or peak compliance

Answer 51

static admittance

Question 52

Ytm

Answer 52

static admittance

Question 53

0.3 – 1.7 mL

Answer 53

static admittance

Question 54

what is considered floppy ossicular chain

Answer 54

above 1.7

Question 55

what is considered stiff in ossicular chain

Answer 55

lower than .3

Question 56

what part of me is being measured by static admittance

Answer 56

ossicular chain plus ™ or middle ear system

Question 57

Static admittance lower in middle ear conditions with increased stiffness

Answer 57

OME Cholesteotoma Ossicular adhesions Space occupying lesions that contact TM or ossicular chain otosclerosis

Question 58

Static admittance higher in middle ear conditions with decreased stiffness

Answer 58

Ossicular chain discontinuity AKA ossicular chain disarticulation TM atrophy

Question 59

What is tympanometric peak pressure measuring? Will this shift along the x or the y axis? What are adult norms for TPP? Which physical structure(s) will affect this measurement if not functioning properly?

Answer 59

ET, shifts right or left on the x axis, +50 to -100 in adults, ET and it is actually measuring the pressure point where the me system is the most efficient

Question 60

What is static admittance measuring? Will this shift along the x or the y axis? What are adult norms for static admittance? Which physical structure(s) will affect this measurement if not functioning properly?

Answer 60

it measures how efficient sound transmission is, measuring stiffness vs floppiness, it will shift along the y axis up and down, .3 to 1.7 is norm, ossicular chain and the tm (middle ear system)

Question 61

ECV

Answer 61

ear canal volume

Question 61

Vea

Answer 61

ear canal volume

Question 62

Noted as Vea or Vec or Veq

Answer 62

ear canal volume

Question 63

ear canal volume tells us

Answer 63

status of the ™ (if it is intact or not, if PE tubes are open or not) if there is something significant in the ear canal that we couldnt see

Question 64

Reported in cc or mL

Answer 64

ear canal volume

Question 65

Increases with age (developmentally)

Answer 65

ear canal volume

Question 66

Clinic norms for adults: 0.9 – 2.0 ml

Answer 66

ear canal volume

Question 67

on average, volume is 2.0

Answer 67

ear canal volume

Question 68

if somebody lost a dome, bug, hair, etc. in the ear from a ha, will it effect canal volume?

Answer 68

will not give an abnormal volume

Question 69

refer to the width of the tympanogram

Answer 69

gradient and width

Question 70

measurement at the halfway point

Answer 70

width

Question 71

ratio of the peak to the halfway point divided by the whole thing

Answer 71

gradient

Question 72

very large width tells us

Answer 72

we have a flat tympanogram

Question 73

why is replicability important

Answer 73

anytime you have a physiologic measure we have to replicate the response make sure the response didnt come by chance run again and make sure you got an unusual result again and it wasn’t your mistake reflexes always replicate