Transcript PowerPoint Presentation - Objective Tests of the Auditory System

Objective Tests
Acoustic Immittance
Otoacoustic Emissions
Auditory Evoked Potentials
Acoustic Immittance
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)
Diagnostic Significance
Conductive Loss
Sensorineural Loss
Cochlear Loss
Retrocochlear Loss
Otoacoustic Emissions
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
Auditory Evoked Potentials
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
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
Summary
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