Otoacoustic Emissions Low-level sounds produced by the cochlea and recordable in the external ear...
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Transcript of Otoacoustic Emissions Low-level sounds produced by the cochlea and recordable in the external ear...
![Page 1: Otoacoustic Emissions Low-level sounds produced by the cochlea and recordable in the external ear canal. Spontaneous Click-evoked Distortion Product Stimulus.](https://reader036.fdocuments.in/reader036/viewer/2022082712/56649f345503460f94c50ef9/html5/thumbnails/1.jpg)
Otoacoustic Emissions Low-level sounds produced by the
cochlea and recordable in the external ear canal.
Spontaneous Click-evoked Distortion Product Stimulus Frequency
![Page 2: Otoacoustic Emissions Low-level sounds produced by the cochlea and recordable in the external ear canal. Spontaneous Click-evoked Distortion Product Stimulus.](https://reader036.fdocuments.in/reader036/viewer/2022082712/56649f345503460f94c50ef9/html5/thumbnails/2.jpg)
History First described by Kemp (1977 &
1978), But predicted by Gold (1948!) Supported by almost simultaneous
discovery of OHC motility Movement into Clinical Use:
Screening for hearing loss Role in Audiologic Battery
![Page 3: Otoacoustic Emissions Low-level sounds produced by the cochlea and recordable in the external ear canal. Spontaneous Click-evoked Distortion Product Stimulus.](https://reader036.fdocuments.in/reader036/viewer/2022082712/56649f345503460f94c50ef9/html5/thumbnails/3.jpg)
Anatomy and Physiology
Generators = Outer Hair Cells “Pre-neural” Low-level event//High level stimuli
produce their own distortions Reduction/Loss of emission in NITTS SOAEs correlated to number of rows
of OHCs
![Page 4: Otoacoustic Emissions Low-level sounds produced by the cochlea and recordable in the external ear canal. Spontaneous Click-evoked Distortion Product Stimulus.](https://reader036.fdocuments.in/reader036/viewer/2022082712/56649f345503460f94c50ef9/html5/thumbnails/4.jpg)
![Page 5: Otoacoustic Emissions Low-level sounds produced by the cochlea and recordable in the external ear canal. Spontaneous Click-evoked Distortion Product Stimulus.](https://reader036.fdocuments.in/reader036/viewer/2022082712/56649f345503460f94c50ef9/html5/thumbnails/5.jpg)
Energy Path:
“Reverse Traveling Wave” is debated
Through Middle Ear: Filtering and attenuation
Into ear canal Note: requirement of healthy middle ear and clear outer ear.
![Page 6: Otoacoustic Emissions Low-level sounds produced by the cochlea and recordable in the external ear canal. Spontaneous Click-evoked Distortion Product Stimulus.](https://reader036.fdocuments.in/reader036/viewer/2022082712/56649f345503460f94c50ef9/html5/thumbnails/6.jpg)
Neonatal Hearing Screening
Transient and Distortion-Product OAEs Rationale: quick, relatively
inexpensive, possibly catching losses in a broader frequency range than ABR
NIH (1994) recommended two-stage protocol combining OAEs and ABR
![Page 7: Otoacoustic Emissions Low-level sounds produced by the cochlea and recordable in the external ear canal. Spontaneous Click-evoked Distortion Product Stimulus.](https://reader036.fdocuments.in/reader036/viewer/2022082712/56649f345503460f94c50ef9/html5/thumbnails/7.jpg)
Audiologic Battery
Assessment of cochlear health in site-of lesion testing
Objective info on peripheral auditory functioning
Correlation to audiogram Assessment of Auditory Efferents
through Contralateral Suppression
![Page 8: Otoacoustic Emissions Low-level sounds produced by the cochlea and recordable in the external ear canal. Spontaneous Click-evoked Distortion Product Stimulus.](https://reader036.fdocuments.in/reader036/viewer/2022082712/56649f345503460f94c50ef9/html5/thumbnails/8.jpg)
Recording OAEs
![Page 9: Otoacoustic Emissions Low-level sounds produced by the cochlea and recordable in the external ear canal. Spontaneous Click-evoked Distortion Product Stimulus.](https://reader036.fdocuments.in/reader036/viewer/2022082712/56649f345503460f94c50ef9/html5/thumbnails/9.jpg)
Spectrum of Sound in Ear Canal
Stimulus Tones
Emission Frequency
Back
gro
un
d N
ois
e
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OAE as Measure of Cochlear Health
![Page 11: Otoacoustic Emissions Low-level sounds produced by the cochlea and recordable in the external ear canal. Spontaneous Click-evoked Distortion Product Stimulus.](https://reader036.fdocuments.in/reader036/viewer/2022082712/56649f345503460f94c50ef9/html5/thumbnails/11.jpg)
Tone Decay:
Loss of audibility for a tone that is on continuously.
Greater decay is indicative of retrocochlear problem.
There are different methods:
![Page 12: Otoacoustic Emissions Low-level sounds produced by the cochlea and recordable in the external ear canal. Spontaneous Click-evoked Distortion Product Stimulus.](https://reader036.fdocuments.in/reader036/viewer/2022082712/56649f345503460f94c50ef9/html5/thumbnails/12.jpg)
Some Tone Decay Tests
Carhart: begin at 0 SL, up in 5 dB steps until tone is heard for a full minute
Olson-Noffsinger: begin at 20 SL, up until heard for full minute.
![Page 13: Otoacoustic Emissions Low-level sounds produced by the cochlea and recordable in the external ear canal. Spontaneous Click-evoked Distortion Product Stimulus.](https://reader036.fdocuments.in/reader036/viewer/2022082712/56649f345503460f94c50ef9/html5/thumbnails/13.jpg)
Tone Decay Results:
Type I: no decay: norm, conduct or cochlear
Type II: heard for longer times as level is increased: cochlear
Type III: No growth with increasing level: retrocochlear
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TONE DECAY SUCCESS?
Sensitivity = 75% Specificity = 91%
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Auditory Brainstem Response:
Response within 10 ms of stimulus waves labeled with Roman
numerals Peaks I, III, and V most useful Latencies are the key measure Disorders will produce delays
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ABR SUCCESS?
Sensitivity = 97% Specificity = 88%