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Presented by: Candice “Evie” Ortiz, AuD. AUDIOGRAM AND IMMITTANCE TUTORIAL. Conduction of Stimuli. Air Conduction Signals are delivered through the outer, middle and inner ears Further processing in the CANS Bone Conduction Signal delivered to the mastoid bone - PowerPoint PPT Presentation
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AUDIOGRAM AND IMMITTANCE TUTORIAL
Presented by: Candice “Evie” Ortiz, AuD
Conduction of Stimuli Air Conduction
Signals are delivered through the outer, middle and inner ears
Further processing in the CANS Bone Conduction
Signal delivered to the mastoid bone○ Bypasses the conductive mechanism
Stimulates both cochlea simultaneously
Masking
Used to obtain accurate thresholds when cross-hearing is likelyAsymmetrical hearing losses of ≥ 40dB or
≥60dB○ Dependent on transducers
Gaps of ≥ 15dB during BC Non-test ear is kept “busy” by the
introduction of a masking noise
Basics of the Audiogram
Classification of Hearing Loss
Normal: -10 to 25 dB Mild: 26 to 40 dB Moderate: 41 to 55 dB Moderately-Severe: 56 to 70 dB Severe: 71 to 90 dB Profound: > 90 dB
Picture Adapted from: Bess, F.H., Humes, L.E., Audiology: The fundamentals, 2003.
Common Audiometric Configurations
Type of Hearing Loss Sensorineural
(SNHL)No air-bone gaps
○ ≥15 dB gap between AC and BC thresholds
Conductive (CHL)≥15dB air-bone gapConsistent with middle
ear pathologyMaximum conductive
component is 60dB
Describing a Hearing Loss
Degree, Configuration, Location, TypeExamples
○ Mild to severe sloping SNHLNo location implies that loss affects all frequecies
○ Severe high frequency SNHL○ Moderate to mild rising low frequency CHL
ExamplesDescribing Hearing Loss
Essentially Mild
Profound
Normal
Normal Mild to Moderate
Time for PracticeDescribing Hearing Loss
Turn to Handouts
What Does It Mean for Speech?
Familiar Sounds Audiogram
Not Audible
Speech TestingSAT, SRT, and WRS
Speech Audiometry Speech Recognition
Threshold (SRT)Adults
Speech Awareness Threshold (SAT)Infants and
Non-Verbal patients Useful in determining test
reliability Malingering Does not understand task
ExamplesReliability Determination
PTA = 3
PTA = 35
Good SRT-PTA agreement Good SRT-PTA agreement
PTA = 10
PTA = 35
Good SRT-PTA agreement Poor SRT-PTA agreement
Clinical Application ofWord Recognition Tests
Determine site of lesionPB Rollover
Surgery candidacy Hearing aid candidacy
If poor WRS, may not be a good candidate
ExamplesWord Recognition Consideration
Dx: OtosclerosisTx: Stapedectomy Q: Which side?
+ Rollover
- Rollover
Very Poor WRSMay not be a good hearing aid candidateConsider CROS style or additional testing
Tympanometry
Tympanometry
Graphic representation of ear compliance in relation to static pressure changes
Normative Tympanometry Values
Peak Pressure is typically WNL in the range of -150 to +25 daPACompliance refers to mobility of tympanic membrane
EAR CANAL VOLUME (cm3)
COMPLIANCE (ml)
MEAN 0.5 0.7
90% RANGE 0.4 to 1.0 0.2 to 0.9
EAR CANAL VOLUME (cm3)
COMPLIANCE (ml)
MEAN 1.1 0.8
90% RANGE 0.6 to 1.5 0.3 to 1.4
Children Ages 3-5 years Adults
Margolis and Heller (1987)
ExamplesTympanometric Configurations: Middle Ear Pathology
Tympanometric Configurations:Middle Ear Pathology
Normal or HypomobilityOtosclerosis
Type A Type As
Type C
Tympanometric Configurations:Middle Ear Pathology
Negative pressureEustachian Tube
dysfunctionDeveloping otitis
mediaTM retraction
Type Ad
Tympanometric Configurations:Middle Ear Pathology
HypermobileAgingAtrophic scarsHealed perforationOssicular
discontinuity
ECV = 7.0
Type B Flat
Perforated TMPatent PE tube
Tympanometric Configurations:Middle Ear Pathology
ECV = 1.0
Type B Flat
Middle ear fluidSerous Otitis
Blocked PE tube
Tympanometric Configurations:Middle Ear Pathology
ECV = 0.2
Type B
FlatImpacted cerumen
Tympanometric Configurations:Middle Ear Pathology
Type B? Type As?
Tympanometric Configurations:Middle Ear Pathology
Middle ear fluid
Acoustic ReflexesART and AR Decay
Acoustic Reflexes Acoustic reflex threshold (ART):
Lowest level at which an AR can be obtained
Most sensitive to middle ear pathologyNormative Values
○ Present for SNHL up to 50 dB○ WNL from 70 to 100 dB○ Elevated responses (≥100 dB) for thresholds
< 50 dB
Stapedial Reflex Arc
Presentation of an intense sound elicits a contraction of the stapedius muscle Changes the ear’s
immittance
“Probe Right” Acoustic Reflexes
ProbeStimulus (ipsi)
Stimulus (contra)
ExamplesCommon Acoustic Reflex Patterns
ART Patterns:Unilateral CHL
CHL, AD WNL, AS
ART Patterns:VIII CN or CPA outside of brainstem
Mild high frequency SNHL, AD
WNL, AS
ART Patterns:Lesions within brainstem which involve reflex pathways
Mild high frequency SNHL, AU
ART Patterns:Facial Nerve Lesion
WNL, AU Absent probe right
Lesion proximal to stapedius nerve
Verticle segment of facial nerve
ART Patterns:Cochlear Impairment
Acoustic Reflex Decay
Retrocochlear Test Measure of ability to
maintain reflex contraction during a continuous stimulation Positive Result
Response decays to ≥ ½ its original magnitude
Pediatric AudiometryTechniques, Age-Appropriate Results, Management
Testing Techniques:Newborns and Infants Otoacoustic Emissions (OAE)
Measures pre-neural signals produced by outer hair cells
Objective measureQuick and easy Non-invasive Sensitive to:
○ Presence of hearing loss○ Problems affecting integrity of cochlea
Auditory Brainstem Response (ABR)If baby does not pass OAE
Testing Techniques:Behavioral Observation Audiometry (BOA)
3 months through 6 monthsParents hold infantObserve natural response to sounds
○ e.g., eye widening or eye shiftsNo reinforcement needed
(Developmental) Age Appropriate Response Levels
TONES (dB)
SPEECH (dB)
0 TO 6 WKS 75 50
6 WKS TO 4 MOS
70 45
4 TO 7 MOS 50 20
7 TO 9 MOS 45 15
9 TO 13 MOS 35 10
As age increases, responses to softer sounds increase
Generally more responsive to speech than tones and narrow band noise
Testing Techniques:Visual Reinforcement Audiometry (VRA)
Age: 6 mos – 3 yrs (developmental) Teach a child to turn their heads in
response to sound, by reinforcing the act with visual stimuli
Requires head control and good vision Can be performed with all transducers
Testing Techniques:Visual Reinforcement Audiometry Patient on lap Focus held ahead
by a distracting assistant
When sound is heard, child turns toward speaker
Action rewarded by an animated, visual reinforcer
Testing Techniques:Conditioned Play Audiometry Age: 3 – 4 yrs Child reacts in
“game” fashion when a sound is heard
Requires active listening
Case StudyLongitudinal
Case Study
Child diagnosed with Trisomy 21 Failed Newborn Infant Hearing Screen No show at 1 month ABR appointment
Audiogram:3 Months Old
Impacted cerumen removed prior
Tymps were WNL Tolerated
headphones but not BC
Hearing Loss??
Age Appropriate Response Levels
TONES (dB)
SPEECH (dB)
0 TO 6 WKS 75 50
6 WKS TO 4 MOS
70 45
4 TO 7 MOS 50 20
7 TO 9 MOS 45 15
9 TO 13 MOS 35 10
Probably not Monitor closely due to
risk factors Every 3 months ME pathologies Impacted cerumen
due to ear canal size
Audiogram:10 Months Old
Developmental Age: 6 mos
More difficult to testMore activeWon’t tolerate
headphones Responding with
eye shifts only
Audiogram:18 Months Old
Will not tolerate headphones
Audiogram:6 Years Old
Play is usually used at 3-4 yr of age
Cerumenectomy 1 wk prior Every 6 months, prior to
audio evaluation. Necessary maintenance
for managing his chronic ME pathology.
And for maintaining good hearing.
Audiogram:9 Years Old
Audiogram:10 Years Old
No cerumenectomy priorImpaction ADUnable to rule out ME
pathology
Pediatric Goals
Verify and/or enable access to speech sounds in order to promote speech and language development