Audiology Exam I
Terms
undefined, object
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- What does an audiologist do?
-
Screens hearing--identify problem
Measure hearing loss
evaulate and dispense technology
teach others to manage/cope with HL
moniter hearing in persons with HL risks
Evaluate vesibular problems -
What does _____ measure?
dB SPL
dB HL
dB SL -
spl- physical scale measurement of sound
HL- hearing compared to normal values
SL- amount above an individual's threshold -
How to convert from...
dB HL to SPL
dB SL to HL -
HL-->SPL: Add dBHL at given frequency to "norm" vaule at that frequency
SL-->HL: Add values to get total in HL - Layers of the Tympanic Membrane:
-
pars tensa: 3 layers (skin fibers, mucus membrane)
Pars flacida: 2 layers (skin and mucus membrane - Muscles of the middle ear
- stapedius and tensor tympani
- If a 2000Hz tone is presented at 25dBSL to someone with a threshold at 10dBHL, what level will the tone be in HL?
- 25 + 10 = 35dB HL
- A 500Hz tone at 50DBHL is at what level in SPL?
- 50 + 11 = 61dB SPL
- Explain occlusion effect and how it influences testing
-
Occlusion effect: When ear is occluded, BC sounds appear louder than when not occluded.
This affects testing because the lack of this effect suggests a Conductive hearing loss. - What do we look for in an otoscopic check?
-
--cone of light
--translucent TM
--manubrium of malleus
--foreign objects, excessive cerumen -
Schwabach test:
proceedure, expected results -
--strike fork and place on forehead/mastoid of patient. When tone cannot be heard, tester places on own head.
--diminished: tester can hear longer
--prolonged: they hear it longer
--normal: both hear it as long -
Rinne test:
proceedure, expected results -
--strike fork and either outside ear until it cannot be heard and then place on mastoid, or
--alternate fork between mastoid and EAC, ask which is louder
--positive: hear better by AC (normal hearning or SN HL)
--negative: hear better by BC (conductive HL) -
Bing Test:
Proceedure, expected results -
--Strike fork, hold on mastoid, have patient press tregus in/out
--Positive: hear "pulse" in sound (normal or SN HL)
--negative: no change (conductive HL) -
Weber test:
proceedure, expected results -
(patient reports Unilateral HL)
--strike fork an place to forehead
--Louder in Problem ear: conductive HL
--Louder in Good ear: SN HL
--Both same: normal, or bilateral HL - Air Conduction, Unmasked symbols
-
Right: O
Left: X - Air Conduction, MASKED
-
Right: ^ (triangle)
Left: [] (square) - BC, Mastoid, UNmasked
-
Right: <
Left: > - BC, Mastoid, MASKED
-
Right: [
Left: ] - BC, Forehead, UNmasked
- Right and Left: l-l
- BC, Forehead, MASKED
-
Right: 7
Left: F - What do the values on a correction chart mean? How to you account for them on an audiogram?
-
+ sound too strong
- sound too weak
add or subtract as symbol says to vaule obtained in testing -
Speech Threshold Testing:
Stimuli
Proceedures
Scoring -
(lowest level speech can be understood)
--Spondees, 2 syllable equal stress words
--familiarize patient with words, present (voice or CD) thru earphones to obtain threshold
--threshold reached when 1/2 are correct -
Speech Detection Threshold:
what it tests
when you use it -
--lowest level where PRESENCE of speech can be DETECTED
--done when ST cannot be obtained
--often used for infants
--use any speech as stimulus -
Speech Understanding/Word Recognition testing:
Stimuli
Proceedure
Scoring -
--uses PB (phonetically balanced) word lists, 50 words
--NOT familiarized with words
--presented in Carrier Phrase (ie "say ____")
--scored in % correct -
When to use Masking for AC
Minimum masking level -
Level Tone NTE - IA > BC (/) NTE
AC (/) NTE + 15 -
When to use Masking for BC
Minimum Masking Level -
A-B gap TE > 10
AC (/) NTE + 15 + OE
OE Used in Low Frequencies:
250Hz--15
500Hz--15
1000Hz--10 -
Normal:
Pressure--
compliance--
volume -
P: -100 to +100 daPa or mmH20
C: .3 to 1.6ccs
V: Kids: .3 to .9cc
Adults: .9 to 2.0cc - How does Immittance audiometry work? how can we infer middle ear pressure using this procedure?
- Tones are presented into EAC while pressure is varried; amount of tone reflected from TM is measured. Measures compliance indirectly--most compliant when P on both sides are equal
-
What does abnormal middle ear compliance infer?
too low
too high -
low: fluid blocking TM from vibrating
high: discontinuity in ossicles or scar tissue over perferation - What 2 aspects of the acoustic reflex do we measure?
-
AR Threshold: Lowest level at which reflex occurs.
AR Decay: stapedius muscle releases when tone still present. - Acoustic reflex response in Conductive HL
-
--cannot measure compliance
--reflex appears absent
--no decay - Acoustic Reflex response in Cochlear HL
-
--reflex present at tones <60dBSPL
--reflex absent in severe HL (cannot make it loud enough)
--no decay - Acoustic Reflex response in 8th nerve/BS problems
-
--ABNORMAL reflexes
--absent, or at levels higher than normal
--decay present - Acoustic Reflext response with Auditory Cortex HL
- --normal reflexes
- Symptoms which may suggest an auditory nervous system problem
-
--unilateral SN HL
--unilateral tinnitus
--vestibular problems, dizziness
--facial nerve problems (numbness, paralysis, twitching)
--asymmetric speech perception (with equal hearing abilities in each ear) - What is recruitment, and what are two ways to meausure it?
-
-->abnormal growth of loudness
-SISI
-High Level SISI - Describe the SISI test
- Tone presented 20 dB SL, and tone 1dB above is "blipped" into it. Count blips. SN HL can detect changes at low SLs
- describe the High Level SISI test
-
play tone around 85 db HL, play "blips" into it.
Auditory nervous problems cannot detect Blips. - What is abnormal adaptation, and what are two tests that measure it?
-
-->hear tone when first presented, then tone decays in intensity
-threshold tone decay test
-super threshold adaptation test (STAT) - Describe the threshold tone decay test
-
-tone presented at 20dB SL for 60 seconds--indicate how long you can hear tone (hand up, etc)
-increase tone in 5dB increments until tone is heard for all 60 seconds
--increase = "x"dB tone decay
- >30dB = 8th nerve HL - Describe the STAT test
-
-present tone at 100db SPL
-if tone ever deays, test is positive for 8th nerve problems - Why do we test the Auditory BS Response, and how are the results interpreted?
-
-used in neonatal screening or when lesion is suspected in BS or 8th nerve
--look for absolute latency, interpeak latency, and morphology of peaks 1 3 and 5 - Decribe the 2 types of Otoacoustic Emitions. When are OAEs absent?
-
--Transient evoked OAEs: use clicks as stimulus
--Distortion product OAEs: test 2 tones together, expet response at frequency difference (ie 4K and 1K, response at 3K)
--absent when SN HL > 25-30dB -
Auditory Evoked Potentials: Cochlea
-time
-how it's measured
-results -
-0 to 2 ms
-surface electrodes deep in ear canal, gives 'clicks'
-identifies meniere's disease -
AEP: Auditory BS Repsonse
-time
-how to measure
-when it's used -
-2 to 10 ms
-surface electrodes on earlobes and forehead
-insert phones deliver clicks
-used in neonatal screening
-measure info from peaks on graph delivered afer 5 minutes -
AEP: Middle Latency Response
-time
-where problem is -
-15 to 60 ms
-bigh BS, Auditory Cortex
-test affected by state of conciousness -
AEP: Late Responses
-time
-where problem is -
-more than 50 ms
-detects problem in cortex
-play 2 tones, identify when "oddball" tone is played
-used in research, not clinically - Audiograms/details: Conductive HL
-
-flat accross frequencies, or worse in LOWS
-air-bone gap noticed
-may have tinnitus in f of most HL
-patients often speak more softly than normal - Audiograms/details: Sensorineural HL
-
-any configuration audiogram
-attenuation and distortion noticed
-caused by noise exposure or aging, affecting high fs more than low
recruitment noticed
-can have tinnitus in f of most HL - Aduiograms/details: mixed HL
-
-air bone gap, with BC levels below normal as well.
-characteristics of both types
-usually have more than one auditory stystem problem. - What does a tympanogram measure?
- Compliance, volume, and pressure relating to the TM
- What are 3 ways to hear via BC?
-
Compression: skull vibrates cochlear fluid
Inertial: ossicles lag behind skull movement
Osseotympanic: skull vibrates--> pressure waves - What might cause a BC threshold to be lower than an AC threshold?
-
-machine calibrated improperly
-headphones/BC osscilator not set on head correctly
-central masking
-statistical variability (machine goes in 5db increments) - Levels of severity of HL on an audiogram, in dBHL
-
<25: Normal
25-40: Mild
40-55: Moderate
55-70: Moderatly severe
70-90: Severe
>90: Profound - What is Intraural Attenuation, and what value do we commonly use?
-
-how much sound skull attributes to which side of head sound came from.
--40 - What is Central Masking?
-
-when case is boarderline as to whether masking is necessary
-present masking, threshold goes up by 5db
--even at louder levels, 5db increase remains the same - what does negative middle ear pressure on a tympanigram indicate
- otitis media
- what does abnormally high volume on a tympanogram indicate?
- perforation in ear drum
-
What is shown in a tympanogram of type:
A
Ad -
A: nomal pressure/compliance/volume
Ad: normal pressure, too much compliance -
Type ____ Tympanogram
As:
B:
C: -
As: norm. pressure, too little compliance
B: "flat," peak is beyond -200, cannot measure compliance (otitis media)
C: neg. pressure, normal compliance (eustachian tube not working)