Lecture 6- Pseudohypacusis Flashcards
What are the causes of pseudohypacusis?
School difficulties
- Low performance despite normal intelligence
- HL is adopted as an accepted excuse
Seeking attention
Psychosocial problems
- Greater degree of false impairment suggests greater psychological problems
- Conflict at home, school, or with friends
- Divorce at home
- High prevalence of emotional problems
More common in girls (2:1)
What are signs and risk factors?
- Referral by attorney
- Reason for visit
Behaviors
- Patient understands soft speech when speakers face is unseen
- Atypical behaviors (e.g., flat affect, argumentative)
- Comments about being confused
- Looking uncertain, concentrating strenously
- Radiating cooperation
- Acting bored
What are some behavioral factors?
Pure-tone audiometry
- Inconsistent pure-tone thresholds (greater than 5 dB test retest)
- Slow, elaborate, or laborious responses
- Flat or saucer shaped HL is most typical (in cases where no organic HL is present)
- Absence of a shadow curve in severe unilateral HL when good ear in not masked
Speech Audiometry
- SRT better than pure tone thresholds
- Half-word responses during SRT
- Pressing earphone to ear
- Bizarre response or error of association
- Seemingly deliberate errors
- Rhyming responses
- Exaggerated straining to understand during the test
What are general principles for test procedures?
- Start with speech audiometry
- Frequency changes is the test signal (speech/tone, frequency, intensity, inter-stimulus timing, ear tested)
Describe how to give instructions for audiometric testing.
- Instruct patient face to face
- Person should be directed to respond to tones by definite raising of an arm
- Familiarize spondee words prior to testing
What are the starting levels that should be used?
Begin with a low signal level (0-20 dB HL)
- Proceed in an ascending fashion
- Compare thresholds from ascending and descending runs
- Ascending SRTs tend to be lower than descending SRTs (gap between SRT and PTA)
What ascending and descending steps should be used?
Use 2 dB steps instead of 5 dB steps
- Present the same level multiple times
What pure-tone audiometry procedures should be used?
- Insert long (~30 seconds) silent intervals between signals
- “Yes/No” response
- “Count the beeps”
What speech audiometry procedures should be used?
- Familiarize with spondee words prior to testing
- Test word recognition at 10-15 db SL or go straight to a soft level (e.g., 30-35 dB HL)
What physiological measures should be used when testing for pseudohypoacusis?
Otoacoustic emissions
- Rules out greater than a mild hearing loss
Acoustic reflex thresholds
- A reflex elicited 10 dB above a voluntary threshold is highly suspicious
- An ART lower than a voluntary threshold is clearly indicative of false results
Auditory evoked potentials
What is the Stenger Test?
Stenger effect: when identical signals are presented to each ear simultaneously, it will only be perceived on the side where it is louder
Stenger Test: signal is presented 10 dB below threshold of the “poorer” ear and 10 dB above threshold to the “better” ear
- If threshold in the “poorer” ear is true, the patient will respond because of hearing the sound in the “better” ear (negative Stenger)
- If there is no HL, patient will perceive the sound only in the “poorer” ear and will not respond (positive Stenger)
What is the Mimimum Contralateral Interference Level?
Useful for estimating true threshold of the “poorer” ear
Can seek MCIL either by lowering the signal to the “poorer” ear from a higher starting point or by raising the signal from 0 dB HL with the same result
The interval just above the point where the patient does not respond is the lowest level in the “poorer” ear that interferes with hearing the signal in the “better” ear (the MCIL)
MCIL in the “poorer” ear roughly equals the SL in the “better” ear
