Acoustic Immittance

Otoacoustic Emissions

Auditory Evoked Potentials

Objective Tests

Instrumentation

Ear Canal Measurements

Static Immittance (compliance)

Tympanometry

Acoustic Reflexes

Acoustic Immittance

Instrumentation

sound source

air pump

analysis section

acoustic reflex stimulus

Acoustic Immittance

Ear canal volume predicted by intensity of reflected sound

Acoustic Immittance

Ear Canal Volume Normative Data

Adults

Mean = 1.5 mL

90% range = 0.6 to 1.5 mL

Children

Mean = 0.7 mL

90% range = 0.4 to 1.0 mL

Acoustic Immittance

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

Tympanometry tracks changes in static immittance over time

Acoustic Immittance

Tympanometric (Jerger) types

Acoustic Immittance

Tympanometric (Jerger) types

Acoustic Immittance

Tympanometric Shape (as recommended by ASHA)

Width of the tympanogram at the 50% amplitude point

Acoustic Immittance

Acoustic Immittance

Normative data for tympanomeric shape

Adults

Mean = 80 daPa

90% range = 50 to 110 daPa

Children

Mean = 100 daPa

90% range = 60 to 150 daPa

Acoustic Immittance

Acoustic Reflex Anatomy and Physiology

Acoustic Immittance

Acoustic Reflex Anatomy and Physiology

Acoustic Immittance

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

Doesn’t change in people with cochlear loss (up to 50 dB HL)

Acoustic Immittance

Conductive Loss

Sensorineural Loss

Cochlear Loss

Retrocochlear Loss

Diagnostic Significance

Instrumentation

Otoacoustic Emissions

Function

Otoacoustic Emissions

Transient Otoacoustic Emissions (TOAEs)

Distortion Product Otoacoustic Emissions (DPOAE)

Otoacoustic Emissions

Application

neonatal hearing screening

differential diagnosis

monitoring cochlear damage

Otoacoustic Emissions

Instrumentation

Auditory Brainstem Response Audiometry (ABR)

Other AEPs

Auditory Evoked Potentials

Instrumentation

Auditory Evoked Potentials

Auditory Evoked Potentials

Auditory Brainstem Response (ABR)

Applications

differential diagnosis

auditory threshold testing

neonatal hearing screening

neurosurgical interoperative monitoring

Auditory Evoked Potentials

Interpertation for ABR

latency

amplitude

morphology

Auditory Evoked Potentials

Auditory Evoked Potentials

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