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

2. 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

3. 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

4. Basics of the Audiogram

5. 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.

6. Common Audiometric Configurations
Stop here

7. 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

8. 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

9. Describing Hearing Loss
Examples

10. Essentially Mild
Profound

11. Normal

12. Normal
Mild to Moderate

13. Describing Hearing Loss
Time for Practice
Turn to Handouts

14. What Does It Mean for Speech?

15. Familiar Sounds Audiogram

16. Not Audible

17. SAT, SRT, and WRS
Speech Testing

18. 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

19. Reliability Determination
Examples

20. Good SRT-PTA agreement

21. Good SRT-PTA agreement
Poor SRT-PTA agreement

22. 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

23. Word Recognition Consideration
Examples

24. Dx: Otosclerosis
Tx: Stapedectomy Q: Which side?

25. + Rollover
- Rollover

26. 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

27. Tympanometry

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

29. 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)

30. Tympanometric Configurations: Middle Ear Pathology
Examples

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

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

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

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

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

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

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

38. ART and AR Decay
Acoustic Reflexes

39. 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

40. Stapedial Reflex Arc
Presentation of an intense sound elicits a contraction of the stapedius muscle
Changes the ear’s immittance

41. “Probe Right” Acoustic Reflexes
Stimulus (contra)
Stimulus (ipsi)

42. Common Acoustic Reflex Patterns
Examples

43. ART Patterns: Unilateral CHL
CHL, AD
WNL, AS

44. ART Patterns: VIII CN or CPA outside of brainstem
Mild high frequency SNHL, AD
WNL, AS

45. ART Patterns: Lesions within brainstem which involve reflex pathways
Mild high frequency SNHL, AU

46. ART Patterns: Facial Nerve Lesion
WNL, AU
Absent probe right
Lesion proximal to stapedius nerve
Verticle segment of facial nerve

47. ART Patterns: Cochlear Impairment

48. 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

49. Techniques, Age-Appropriate Results, Management
Pediatric Audiometry

50. 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

51. 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

52. (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

53. 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

54. 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

55. VRA Video
VRA In Action

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

57. Longitudinal
Case Study

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

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

60. 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

61. 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

62. 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.

63. 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 dB better.

64. 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

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

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