Download test ear

Otoscopy, hearing screening
(AC) and pure tone testing
with AC and BC
Lecture 5
Screening and Assessment
 Screening Options
 Case Hx
 HHIE
 Otoscopy
 Pure tone AC screening
 Pure tone audiometric assessment
 Air Conduction or Soundfield if unable to tolerate
headphones
 Bone Conduction
 Procedures for PT testing
 Variables affecting results

Cross hearing in pure tone testing
Hearing Screening Options
Options
Condition
Case History Questions Self Report
background
Questionnaire
HHI-E/ HHI-A
Pure tone hearing
screen
Otoscopy
Fail /Criteria
None
Perception of
Handicap
Pass < 10
Refer>10
Detection of sound
Pass 20 dB, children
Pass 25 dB HL, adult
Condition of ear canal
Varies
and middle ear
Drainage, wax, foreign
body, asymmetry,
redness
Case History
 Hearing History



Do you have a hearing loss in one or both of your ears?
Was your HL sudden in onset?
Do you have any ringing or noises in your ears?
 Medical History, History of Noise Exposure



Have you had a recent illness that could have caused your
HL such as sudden noise exposure, viral illness, meningitis,
mumps, syphilis, aminoglycoside use, high fever, diuretic
use or head trauma?
Do you have any recent discharge or drainage?
Do you have any pain, fullness, or discomfort in your ears?
 Family History
 Determine time of onset of HL
Hearing Handicap Inventory Elderly
(HHIE: Ventry & Weinstein, 1983)
10 item, yes, no, sometimes; Paper/pencil format
 Perceived psychosocial effects of hearing loss
 Psychometric Properties



Strong internal consistency
Strong test retest reliability (.84)
High correlation with degree of hearing loss
 Pass/Fail Criteria
 Total Score < 10: Pass
 Total Scores > 10: Refer
 Total Scores > 18: Benefit from HA
 http://www.ausp.memphis.edu/harl/
When to screen, what to expect
 Clinical Indications Adults
 Screen as needed, requested or when they
have conditions that place them at risk for HL
(i.e. recreational noise exposure, family hx,
concerned family member)
 See ASHA guidelines
 Expected Outcomes
 Identification of those persons most likely to
have HL that requires referral
 Does not differentiate between types of HL
(conductive, sensorineural etc)
Normal TM
 Color: grayish, translucent appearance.
 Structures behind TM:
Handle of malleus touches TM- actually draped over bone
and is visible. Manubrium is closest to the drum and is most
prominent.
 The tip at the bottom-most aspect is the umbo.
 The light reflex:
 Light originating from scope reflects off the surface of the
drum, making a triangle that is visible below the malleus.
 Annulus:
 ring surrounding TM

Otoscopy
Otoscopy/Video Otoscopy
 Pull up on pinna and away for adults
 Pull downward on ear lobe for children
 Carefully place speculum in ear canal

Rotate otoscope anteriorly towards the nose
and attempt to ID landmarks
Non Diagnostic Otoscopy




Wax
Fluid in middle ear
Perforated eardrum
Presence of foreign body
Landmarks
 Annulus
 Manubrium
 Umbo
 Cone of Light
 Incus (shadow)
 Pars Tensa
 Pars Flaccida
Setting/Equipment/Specifications
 Conduct hearing screening in a clinical or
natural environment conducive to obtaining
reliable screening results
 Determine ambient noise levels
 Be sure equipment is calibrated annually
 Perform listening check prior to administering
pure tone test
Clinical Process (Hall and Mueller, 1997)
 Briefly inspect each ear for evidence of abnormality
(ear canal collapse, drainage etc)
 Seat patient comfortably with profile toward you
 Instruct patient to respond when they just barely hear
the stimulus or even if they just think they heard a
sound

Use appropriate language level
 Response mode:
 Press a button
 Raise hand
 Give verbal response
Clinical Process- ASHA Guidelines
http://www.asha.org/docs/html/GL1997-00199.html
 Protocol – Adults
 Tones
 Frequencies
 Protocol – Kids
 Tones
 Frequencies
 Present at 1000,
2000 and 4000 Hz

Level
 25 dB HL

 Present at 500,
1000, 2000 and
4000 Hz

Level
 20 dB HL
Ear
 Right and left ear
individually
Subjective
Procedure

Ear
 Right and left ear
individually
Tips in conducting hearing screening
 Position client in chair
 Adults – facing away from examiner (only after giving
instructions)
 Child – varies


If they can follow directions w/o difficulty – face away
If they can’t follow directions – face towards examiner and
give more feedback visually
 Provide instructions – pg 94
 Position headphones
 Familiarize with task and then test
Tips in conducting hearing screening
 Present a pure tone signal to the better ear (50 dB




HL)
If patient responds, then drop down by 10 dB steps
until you obtain a response at desired screening level
(20 dB HL – children, 25 dB HL for adults)
Use pure tone signals of 1-2 seconds duration
If NR from patient, increase in 5 dB steps until the
patient responds, and then drop down in 10 dB steps
Stop presenting tones once you obtain a response at
the desired screening level
Audiometric Test Battery
Options
Purpose
Results
Pure tone AC threshold Determines degree of dB HL
HL
Pure tone BC threshold Determines type of
HL
dB HL , but
compares AC and
BC to yield CHL,
SNHL or MHL
Acoustic Immitance
Determines condition
of ME and AR
Pressure units and
type of tympanogram
Speech Audiometry
Determines extent of
speech
understanding
Percent of words
correct
Pure tone audiometry – threshold
testing
 Cornerstone audiometric assessment tool
 Several researchers involved in development
of technique for hearing testing (Carhart & Jerger,
Hughson & Westlake)
 Purpose: to quantify the amount, type and
configuration of hearing loss
 Results recorded on audiogram
 Not screening
 Scope of Practice: Limited to audiology
Air and Bone
 Degree of Hearing Loss

Determined by pure tone air results
 Type of Hearing loss

Determined by comparing pure tone bone
results with pure tone air results
 Configuration of Hearing loss

Determined by pattern of pure tone air results
Current Procedure (modified Hughson
Westlake Method)
 Begin in better ear
 Use warbled, pulsed or conventional pure tones
 Begin at 1000 Hz
 Assess mid octaves if gap of more than 20 dB
 Familiarize with task



Signal duration: ____ seconds
Present a pure tone signal to the better ear at a
level comfortably ________the patient’s presumed
threshold
Usually 40 dB above threshold (typically at 50 dB
HL) for normal hearing
Determining Threshold
 After demonstrating familiarization, then
begin threshold search with down 10, up 5
rule…
 Increase the intensity level in ____ dB steps
until the patient responds
 Go back down another ____dB and present
the stimulus once more
 Increase the intensity again in ___ dB
increments, seeking a response
 The patient’s threshold for the stimulus is the
lowest level obtained in at least half of a
series of presentations
 Record threshold level on audiogram
 Go on to the next frequency using same
method until all frequencies are obtained
(250, 500, 1,2,4,&8 K)
 Go to other ear after the first ear is
completed.
Variables affecting results
 Cognitive ability


Adults
Children
 May have to do an alternative assessment
Alternate assessments
VRA and Conditioned Play Audiometry
 Conditioned Play Audiometry
http://www.youtube.com/watch?v=_eKn-lrGYZo
 Visual Reinforcement audiometry
http://www.youtube.com/watch?v=S45H3i2ulto
 http://www.youtube.com/watch?v=_6wtsoTfg6A&list=PLV7nKx5rKr5Se
aKOZeea8s1mSpbCMijDu&index=37
Variables affecting results
 Environment


Ambient noise levels cannot exceed an
allowable value (ASHA guidelines)
Distractors


Visual
Proprioception
Variables affecting results
 Stimulus



Starting level – must provide familiarization
Duration of stimulus
Type of tone
 Presentation pattern
Pitfalls and Fixes
 False Positives and False Negatives
 Collapsing ear canals
 Standing waves
 Tactile response
Pure Tone Average (PTA)- pg 98
 PTA - simple summary of degree of HL
 Conventional formula:

Average of 500, 1000, 2000 Hz / 3
 Alternative 4 frequency formula

Average of 500, 1000, 2000, 4000 Hz / 4
Audiogram
 Calculate Pure tone average
Cross-over Hearing
 Cross over can occur through Air Conduction or
Bone conduction
 The sound presented to the test ear crosses
through the skull and stimulates the hair cells of the
opposite cochlea
 The ear that is actually responding to the tone is
not the test ear
 Conditions



When one ear hears much better than the other
When there are large differences between the ears
If assessing at very high intensity levels
Cross-over Hearing AC
When values >/= 40 dB
consider using masking to reevaluate thresholds in which
ear?
Frequency (Hz)
500
0
10
dB Hearing Level
20
30
40
50
60
70
80
90
100
1000
2000
3000
4000
6000
Interaural attenuation (IA)
 Amount of reduction in intensity that occurs
when a signal crosses the head from one ear
to the other
 Sound can cross via AC or BC



Typical IA value = 40 dB HL for AC
Typical IA value = 0 dB HL for BC
Varies by individual, HL and frequency
Cross-Over Hearing in Air Conduction
 Is AC (test ear) – 40 dB > AC (non test ear)?
 Examples:
250
0
10
20
30
40
50
60
70
80
90
100
110
120
500
1000
2000
4000
8000
250
0
10
20
30
40
50
60
70
80
90
100
110
120
500
1000
2000
4000
8000
BC
 Complex phenomenon that involves
interaction of 3 different ways to stimulate
the cochlea.



*Distortional BC – of bony cochlear
labyrinth
Inertial BC – inertial response of
middle ear ossicles and inner ear
fluids
Osseotympanic BC – radiation of
sound energy into external ear
canal
Each
contributes
differently to
the BC
response
Set-up
 BC testing completed with test ear uncovered
 Non test ear can be covered when using
masking
 If the ear is covered, then a BC signal sounds
louder
 Increase in sound pressure in the ear canal
Air vs Bone Results
 AC can be the same as BC
 AC can be worse than BC = Air Bone Gap
 BC should not be worse than AC – slight
variations can be obtained
Occlusion Effect (OE)
 Demonstration
 Occurs for frequencies </= 500 Hz
 Occurs in normal hearing or SNHL if ear
occluded
 Does not occur in CHL
Interaural attenuation (IA) for BC
 Amount of reduction in intensity that occurs
when a signal crosses the head from one ear
to the other
 Sound also crosses via BC
 IA values for BC

Compare AC and BC threshold of the test ear

IA = 10 dB HL
Cross Hearing in BC
 Only a concern when there is an ABG in the
test ear

Is AC (test ear) – BC (test ear) > 10 dB?
 Air-Bone-Gap in Test Ear > 10 dB