Electrophysiological Testing
What do electrophysiological tests measure?
electrical/physiological properties of cells and tissues (some type of electrical or physiological response)
What do behavioral tests measure?
Patient responses
What are the symbols for air conduction testing?
Bonus 100 pts: masking symbols too
O (red) - right ear
X (blue) - left ear
Red triangle - right ear tested, left ear masked
Blue square - left ear tested, right ear masked
Name one test that does NOT test hearing
Electrophysiological Testing: tympanometry, acoustic reflex testing, otoacoustic emissions, auditory brainstem response, or auditory steady state response
Name one difference between a screening and a diagnostic test.
Screening:
-Test large numbers of subjects
-Test simply and efficiently
- Detect indicators of HL for referral Don’t refer those WNL
Diagnostic Testing:
Test specific individuals identified at risk
Test in detail and at greater cost
Establish presence or absence of HL / definitive diagnosis
What are the benefits of electrophysiological testing?
2 tests that measure hearing thresholds (quantity of hearing loss)
Air conduction and bone conduction
What is hearing WNL for adults? For children?
0-25 dB HL for adults
0-15 dB HL for children
Why do children need to hear better than adults?
Children are still learning language
What is CPA and what population is it the preferred testing method?
Conditioned Play Audiometry; preschoolers
This test provides information about the integrity of the outer hair cells
Otoacoustic Emissions (OAE)
The lowest intensity a patient responds to 2 times
threshold (in pure tone testing)
What is plotted on an audiogram?
Hearing threshold responses to pure tones at specific frequencies (Hz) measured in dB
Explain the 3 types of tympanogram results (Type A, B and C)
Type A=TM movement WNL
– Indicative of normal middle ear function
- peak at about 0
Type B=NO TM movement
– With normal ear canal volume, indicative of: Fluid in ME (most common) or Fixed ossicles
– With large ear canal volume, indicative of:Perforation in TM or Patent (open) PE tube
-flat line
Type C=TM retraction
– Indicative of Eustachian tube dysfunction
-peak at less than 0
Why is OAE screening NOT the preferred test of choice of NBHS?
BONUS (+100): What is the preferred test for NBHS?
OAE screen – will miss babies with ANSD
BONUS: Auditory Brainstem Response (ABR)
Can be used to predict hearing sensitivity across various frequencies
Auditory Brainstem Response (ABR)
Through "air"/normal transmission of sound; travels through OE, ME, and IE
How do you know if HL is conductive only?
Bone conduction thresholds are better than air conduction thresholds AND hearing is WNL with BC
Bone conduction without masking and sound field testing is not _______.
BONUS (+200): What are the audiogram symbols for unmasked bone conduction left/right ears?
ear specific
BONUS:
Right Ear: red <
Left Ear: Blue >
Name one reason a child would be referred to an audiologist after a school hearing screening.
- 30dB HL or greater at 2 or more frequencies on 2 consecutive tests at least 2 and no more than 6 weeks apart*
-OR-
40dB HL or greater at 1 frequency on 2 consecutive tests at least 2 and no more than 6 weeks apart*
-OR-
Evidence of pathology
Referral for “medical-audiological” examination *CCS (CA Children’s Services – must be more than 6 weeks apart)
Specific responses are identified in specific time windows after presenting a sound stimulus; measures integrity of the auditory system through the brainstem or beyond
Evoked potentials testing
Why does bone conduction test the better ear?
The whole skull vibrates, so the "better" ear will "hear" it.
How do you know if HL is mixed (conductive and sensorineural)?
BC thresholds are better than AC but still NOT WNL
Describe the processing of bracketing
Describe the Stenger Test (how we test people who are faking a hearing loss)
BONUS (+100): What do we call someone who is faking a hearing loss?
Louder input, but below “threshold” in poorer ear
■ If telling truth, should be too quiet to hear
Quieter input, but above threshold in better ear
■ If telling truth, should be easily audible
BONUS: malingerer