Audiology Exam 4

Front 1

the immittance battery of tests

Back 1

1. is sensitive in detecting middle ear disorder

2. can be helpful as a cross-check to pure-tone audiometry

3. can be useful in differentiating cochlear from retrocochlear disorder

Front 2

impedance vs. admittance vs. immittance

Back 2

immittance is the accepted clinical term that encompases both

Front 3

immittance

Back 3

total opposition to the flow of energy through a vibrating system and total energy flow through a vibrating system

Front 4

immittance test battery

Back 4

1. tympanometry

2. static immittance

3. acoustic thresholds

Front 5

3 parts of probe tip

Back 5

1. air pump (changes pressure in space between probe tip and ear drum)

2. speaker (transmits sound into ear canal space)

3. microphone (picks up sound generated)

Front 6

when probe tip pump is set at atmospheric pressure

Back 6

eardrum behaves normally, most flexible, most sound absorbed

Front 7

when probe tip set at high pressure

Back 7

forces ear drum inwards, increases rigidity, more sound reflected back to probe tip

Front 8

when probe tip set at low pressure

Back 8

forces ear drum outwards, increases rigidity, more sound reflected back to probe tip

Front 9

tympanogram horizontal axis

Back 9

pressure changes- from -300 through 0 (atmospheric) to +200, in decaPascals (daPa)

Front 10

tympanogram vertical avis

Back 10

amount of sound absorbed (admitted) by the eardrum; mhos

Front 11

mho

Back 11

opposite of ohm, quantified admittance to the flow of energy

Front 12

Back 12

Type A- normal ear, no air-bone gap expected

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Back 13

Type B- eardrum inflexible, fluid in middle ear; generally otitis media with effusion

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Back 14

Type C- negative pressure point, consistant with eustachian tube malfunction; may signal oncoming or healing ear infection

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Back 15

Type AS- normal middle ear pressure but inflexible; otosclerosis or cholesteatoma

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Back 16

Type AD- no pressure point, signals ossicular disarticulation

Front 17

acoustic reflex

Back 17

when a sound is of sufficient intensity, it will elicit a reflex of the middle-ear musculature; primarily of the stapedius muscle

-activated in both ears even if only stimulated in one

-tests CONDUCTIVE component, will be normal if only sensorineural damage

Front 18

normal range of acoustic reflex

Back 18

70dB-100dB

Front 19

functions of acoustic reflex

Back 19

may be inner ear protection- we don't really know

Front 20

acoustic reflex arc

Back 20

stimulus noise->cochlea->8th nerve->brain stem->7th nerve->back to BOTH ears and stapedius muscles

Front 21

nomenclature for acoustic reflexes

Back 21

right/left ipsilateral (uncrossed)

right/left contralateral (crossed)

Front 22

the acoustic reflex is defined by

Back 22

the stimulated ear

Front 23

acoustic reflex if sensorineural hearing loss

Back 23

will still be normal

Front 24

fluid in ear- effect on acoustic reflex

Back 24

obscures

Front 25

acoustic reflex if conductive component in one ear (ex. right ear)

Back 25

-right ear ipsilateral and right and left ear contralateral acoustic reflex will be absent

-left ear ipsilateral acoustic reflex will be normal

Front 26

acoustic component if conductive problems in both ears

Back 26

absent

Front 27

if normal tympanogram but absent acoustic reflex

Back 27

check which pathways are involved- may be facial nerve weakness on one side

Front 28

if normal tympanogram but absent contralateral acoustic reflexes

Back 28

consistent with brainstem lesion

Front 29

acoustic reflex decay

Back 29

normal for reflex to maintain strength for 10 seconds; if decays before, may be 8th nerve lesions

Front 30

optimal listening intensity

Back 30

1000 and 2000 Hz (?)

Front 31

four major applications of auditory evoked potential measurement

Back 31

1. infant hearing screening (most important)

2. prediction of hearing sensitivity

3. diagnostic assessment of central auditory nervous system function

4. monitoring auditory nervous system function during surgery

Front 32

equiptment for auditory evoked potentials

Back 32

1. differential amplifier

2. bandpass filter

3. signal averaging (summing) computer

Front 33

auditory evoked potential

Back 33

small electrical voltage potentials evoked by sound

Front 34

differential amplifier

Back 34

rejects electrical activity recorded at two different electrodes when the electrical impulses are identical (leaving the AEP)- called common mode rejection

Front 35

bandpass filter

Back 35

auditory evoked potential frequencies are restricted to a vary narrow band; bandpass filtering cuts out extreme high and low frequencies not ordinarily expected to fall in the range of the AEP

Front 36

signal averaging (summing) computer

Back 36

extracts the time-locked auditory evoked potential from the random EEG noise; several thousand stimuli (clicks) presented, electrical activity summed towards zero so eventually AEP is left

Front 37

auditory brainstem response (ABR)

Back 37

most commonly used evoked potential, occurs within the first 10 msec following signal onset ("time-locked")

Front 38

electrocochleography

Back 38

putting probe (surgically) near cochlea, monitor 8th nerve during surgery, records 3 electrical potentials

Front 39

3 electrical potentials recorded by electrocochleography

Back 39

1. summating potential (builds and sparks AP)

2. cochlear microphonic

3. action potential (wave I of ABR)

Front 40

source of cochlear microphonic believed to be

Back 40

hair cells

Front 41

source of ABR waves

Back 41

uncertain but come from brainstem

Front 42

why ABR is useful

Back 42

-can be recorded from surface electrodes

-waves robust

-patient can be asleep etc.

-repeatable

Front 43

ABR- wave latencies vs. wave amplitudes

Back 43

wave latencies (delays between waves) stable across patients, amplitudes far less stable

Front 44

wave V of ABR

Back 44

most robust wave in ABR; latency increases as auditory stimulus decreases; amplitude decreases as stimulus intensity decreases

-used to estimate hearing threshold for difficult-to-test adult

-may be low for infants (only test high/low), become robust for everyone ~18 months

Front 45

why ABR is tested binaurally

Back 45

faster, speeds up infant screening

Front 46

cortical radiations and auditory cortex radiations

Back 46

less clinical utility due to variability of AEPs across subjects, more for research than clinical

Front 47

presumed anatomical source of AEPs

Back 47

late latency response- auditory cortex

middle latency response- medial geniculate body (?)

auditory brainstem response (ABR)- brainstem

Front 48

late latency responses are

Back 48

less reliable; ABR more reliable

Front 49

auditory steady-state response (ASSR)

Back 49

the auditory evoked potential, elicited with modulated tones that can be used to predict hearing sensitivity in patients of all ages

-elicited by a tone; ASSR follows modulation rate of the stimulus

Front 50

otoacoustic emissions

Back 50

-backwards emitted wave

-cochlear echoes

-related to tinnitus

-outer hair cells presumed source- noise changes shape, shape changing causes vibrations on basilar membrane, vibrations emanate backwards through system- so need healthy ear to get them

Front 51

2 classes of OAEs

Back 51

-spontaneous OAEs- when not stimulated, in 50% of people with hearing WNL, absent when not normal; not linked to tinnitus

-evoked OAEs- need stimulus- Transient Evoked OAEs and Distortion Product OAEs

Front 52

Transient Evoked OAEs

Back 52

click-evoked

Front 53

Distortion Product OAEs

Back 53

two-tone stimulus, cochlea generates another tone "of its own", called distortion product

Front 54

clinical applications for OAEs

Back 54

1. infant screening

2. pediatric assessment

3. cochlear function monitoring

4. certain diagnostic cases

-doesn't measure degree of hearing loss accurately, but whether there is loss or not; helps determine diagnosis

Front 55

electronystagmography (ENG)

Back 55

vestibular assessment

-nystagmus (eye movements), etc.

Front 56

using audiologic knowledge- what to ask/tell patient

Back 56

don't tell them how they hear, ask how it affects them (communication etc.)

Front 57

elements of a report

Back 57

-case history

-otoscopic inspection

-immittance

-the audiogram: type of hearing loss, degree of hearing loss, configuration of hearing loss, symmetry of hearing loss

-speech audiometry

-recommendations (follow-up etc.)

Front 58

identify need for intervention

Back 58

-degree/type of hearing loss, audiogram morphology, degree of handicap, patient motivation

Front 59

process of getting hearing aid

Back 59

-assessment (audiological and medical)

-earmold impressions

-hearing aid assessment

-follow-ups

Front 60

questions to be anwered by the audiological assessment for a hearing aid

Back 60

-auditory needs- hearing loss

-treatment needs- why seeking hearing aid, motivation, patient's physical and psychological status, etc.

Front 61

determining treatment needs

Back 61

-self-assessment scales

-loudness discomfort data

Front 62

factors affecting negative prognosis

Back 62

-patient doesn't perceive a problem

-not enough or too much hearing loss

-"difficult" hearing loss

-very poor speech recognition

-disease in middle ear

Front 63

amplification strategies/options

Back 63

-type of amplification system (hearing aid, implant, etc.)

-which ear (monaural vs. binaural, better or worse)

-device style

Front 64

binaural advantage of hearing aids

Back 64

-loudness enhancement

-improved spatial hearing (localization)

-balanced hearing

Front 65

hearing aid fitting approaches

Back 65

-estimating amplification targets (soft, moderate, and loud sounds)

-ensure that soft sounds audible, loudness discomfort level not exceeded

-get patient input

Front 66

when hearing aid arrives

Back 66

check to make sure it's working