AUDIOGRAM AND IMMITTANCE TUTORIAL Presented by: Candice “Evie” Ortiz, AuD AUDIOGRAM AND IMMITTANCE TUTORIAL

Conduction of Stimuli Air Conduction Bone 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 likely Asymmetrical 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 Stop here

Type of Hearing Loss Sensorineural (SNHL) Conductive (CHL) No air-bone gaps ≥15 dB gap between AC and BC thresholds Conductive (CHL) ≥15dB air-bone gap Consistent with middle ear pathology Maximum conductive component is 60dB

Describing a Hearing Loss Degree, Configuration, Location, Type Examples Mild to severe sloping SNHL No location implies that loss affects all frequecies Severe high frequency SNHL Moderate to mild rising low frequency CHL

Describing Hearing Loss Examples

Essentially Mild Profound

Normal

Normal Mild to Moderate

Describing Hearing Loss Time for Practice Turn to Handouts

What Does It Mean for Speech?

Familiar Sounds Audiogram

Not Audible

SAT, SRT, and WRS Speech Testing

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

Reliability Determination Examples

Good SRT-PTA agreement

Good SRT-PTA agreement Poor SRT-PTA agreement

Clinical Application of Word Recognition Tests Determine site of lesion PB Rollover Surgery candidacy Hearing aid candidacy If poor WRS, may not be a good candidate

Word Recognition Consideration Examples

Dx: Otosclerosis Tx: Stapedectomy Q: Which side?

+ Rollover - Rollover

May not be a good hearing aid candidate Very Poor WRS May not be a good hearing aid candidate Consider CROS style or additional testing

Tympanometry

Tympanometry Graphic representation of ear compliance in relation to static pressure changes

Normative Tympanometry Values Children Ages 3-5 years Adults 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 Peak Pressure is typically WNL in the range of -150 to +25 daPA Compliance refers to mobility of tympanic membrane Margolis and Heller (1987)

Tympanometric Configurations: Middle Ear Pathology Examples

Tympanometric Configurations: Middle Ear Pathology Type A Type As Normal or Hypomobility Otosclerosis

Tympanometric Configurations: Middle Ear Pathology Negative pressure Eustachian Tube dysfunction Developing otitis media TM retraction Type C

Tympanometric Configurations: Middle Ear Pathology Hypermobile Aging Atrophic scars Healed perforation Ossicular discontinuity Type Ad

Tympanometric Configurations: Middle Ear Pathology Flat Perforated TM Patent PE tube ECV = 7.0 Type B

Tympanometric Configurations: Middle Ear Pathology Flat Middle ear fluid Serous Otitis Blocked PE tube ECV = 1.0 Type B

Tympanometric Configurations: Middle Ear Pathology Flat Impacted cerumen ECV = 0.2 Type B

Tympanometric Configurations: Middle Ear Pathology Middle ear fluid Type B? Type As?

ART and AR Decay Acoustic Reflexes

Acoustic Reflexes Acoustic reflex threshold (ART): Lowest level at which an AR can be obtained Most sensitive to middle ear pathology Normative 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 Stimulus (contra) Stimulus (ipsi)

Common Acoustic Reflex Patterns Examples

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

Techniques, Age-Appropriate Results, Management Pediatric Audiometry

Testing Techniques: Newborns and Infants Otoacoustic Emissions (OAE) Measures pre-neural signals produced by outer hair cells Objective measure Quick 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 months Parents hold infant Observe natural response to sounds e.g., eye widening or eye shifts No reinforcement needed

(Developmental) Age Appropriate Response Levels As age increases, responses to softer sounds increase Generally more responsive to speech than tones and narrow band noise Tones (dB) Speech (dB) 0 to 6 wks 75 50 6 wks to 4 mos 70 45 4 to 7 mos 20 7 to 9 mos 15 9 to 13 mos 35 10

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

VRA Video VRA In Action

Testing Techniques: Conditioned Play Audiometry Age: 3 – 4 yrs Child reacts in “game” fashion when a sound is heard Requires active listening

Longitudinal Case Study

Case Study Child diagnosed with Trisomy 21 Failed Newborn Infant Hearing Screen No show at 1 month ABR appointment

Hearing Loss?? Audiogram: 3 Months Old Impacted cerumen removed prior Tymps were WNL Tolerated headphones but not BC Hearing Loss??

Age Appropriate Response Levels Probably not Monitor closely due to risk factors Every 3 months ME pathologies Impacted cerumen due to ear canal size Tones (dB) Speech (dB) 0 to 6 wks 75 50 6 wks to 4 mos 70 45 4 to 7 mos 20 7 to 9 mos 15 9 to 13 mos 35 10

Audiogram: 10 Months Old But now we have BC information. Developmental Age: 6 mos More difficult to test More active Won’t tolerate headphones Responding with eye shifts only But now we have BC information. Use of hand-held bone oscillator Moderate Conductive loss At age 10 months, immittance is more reliable. Flat tymps AU Cerumen cleared prior Probably MEE AU

Audiogram: 18 Months Old Will not tolerate headphones Still not tolerating headphones. But now localizing, so VRA is appropriate. Still showing a conductive loss, but now mild. Immittance – ET dysfunction rather than MEE.

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. Notice that SRT is still lower than pure tone average. A function of developmental level and interest level. “Minimal Response Levels” for tones – true thresholds probably 10-15 dB better.

Audiogram: 9 Years Old SRTs match PT levels. PT levels are probably true threshold levels now. Cerumenectomy prior to test today (every 6 mo). Normal tymps at last. Making progress w/ speech and language

Audiogram: 10 Years Old No cerumenectomy prior Impaction AD Unable to rule out ME pathology

Pediatric Goals Verify and/or enable access to speech sounds in order to promote speech and language development