audiology objectivemeasures

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Acoustic Immittance

Otoacoustic Emissions

Auditory Evoked Potentials

Objective Tests


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Instrumentation

Ear Canal Measurements

Static Immittance (compliance)

Tympanometry

Acoustic Reflexes

Acoustic Immittance


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Instrumentation

sound source

air pump

analysis section

acoustic reflex stimulus

Acoustic Immittance


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Ear canal volume predicted by intensity of reflected sound

Acoustic Immittance


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Ear Canal Volume Normative Data

Adults

Mean = 1.5 mL

90% range = 0.6 to 1.5 mL

ChildrenMean = 0.7 mL

90% range = 0.4 to 1.0 mL

Acoustic Immittance


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Static immittance is the measurement of tympanic membrane

and middle ear mobility

Normative Data for Adults

Mean = 0.8 mL

90% range = 0.3 to 1.4 mL

Normative Data for Children

Mean = 0.5 mL

90% range = 0.2 to 0.9 mL

Acoustic Immittance


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Tympanometry tracks changes in static immittance over time

Acoustic Immittance


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Tympanometric (Jerger) types

Acoustic Immittance


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Tympanometric (Jerger) types

Acoustic Immittance


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Tympanometric Shape (as recommended by ASHA)

Width of the tympanogram at the 50% amplitude point

Acoustic Immittance


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Acoustic Immittance


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Normative data fortympanomeric shape

Adults

Mean = 80 daPa

90% range = 50 to 110 daPa

ChildrenMean = 100 daPa

90% range = 60 to 150 daPa

Acoustic Immittance


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Acoustic Reflex Anatomy and Physiology

Acoustic Immittance


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Acoustic Reflex Anatomy and Physiology

Acoustic Immittance


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Acoustic Reflex Threshold

Definition

ART for pure tones = 85 to 95 dB HL for normally hearing

people

ART for Speech = 10 to 20 dB less for pure tones

Doesnt change in people with cochlear loss (up to 50 dB

HL)

Acoustic Immittance


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Conductive Loss

Sensorineural Loss

Cochlear Loss

Retrocochlear Loss

Diagnostic Significance


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Instrumentation



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Function



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Transient Otoacoustic Emissions (TOAEs)

Distortion Product Otoacoustic Emissions (DPOAE)



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Application

neonatal hearing screening

differential diagnosis

monitoring cochlear damage



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Instrumentation

Auditory Brainstem Response Audiometry (ABR)

Other AEPs



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Instrumentation



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Auditory Brainstem Response (ABR)

Applications

differential diagnosis

auditory threshold testing

neonatal hearing screening

neurosurgical interoperative monitoring



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Interpertation for

ABR

latency

amplitude

morphology



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Summary of Auditory Evoked Potentials

AEP Site Application

Electrocochleography VIII Nerve Hearing Testing

ABR VIII Nerve and Brainstem See Previous

Middle Latency Response Primary Auditory Cortex Hearing Testing

Late Vertex Response Upper Level Cortex Central Auditory Problems

P300 Frontal Lobe Physiological Psychology


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Summary

audiology objectivemeasures

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