Download Nonorganic Hearing Loss

Nonorganic
Hearing Loss
SPA 4302
Summer 2006
Some Terminology
• Pseudohypacusis – False hearing loss
• Functional – Loss with no organic disorder
detected.
• Psychogenic – Loss/disorder arising from
psychological conditions,
– older synonym was hysterical deafness
• Nonorganic – Apparent loss with no known
disorder or insufficient evidence to explain it
• Malingering – deliberately faking a loss
Patients with Nonorganic Hearing Loss
• Adults seeking financial or other gain
(predominantly male)
• Children seeking attention or ?
• Persons with psychological disorders
– conversion neurosis
What are the first signs?
• Disagreement:
– among test results
• SRT vs PTA
• Audiometric vs AR thresholds, etc)
– between test results and behavior
• Lack of Crossover
– no shadow curve in the unmasked results
• Odd results
– Repeating half of the spondees?
Tests for Nonorganic Hearing Loss
• The Stenger – for unilateral HL
• Delayed Auditory Feedback Tests
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Tone Tap Test
Delayed Speech Test
Varying Intensity Story Test
Objective tests (AR, AEPs, OAEs)-
The Stenger
• Based on the “Stenger Phenomenon” When a
listener is presented with the same type of sound
in both ears, s/he will only hear a single sound
and hear it in the ear in which it is louder.
• 2 tones:
– At + 10 dB SL in good ear
– At – 10 dB SL in “bad” ear
• If no response: you’ve caught them! --why?
– Part II: reduce level in “bad” ear until they respond:
“minimum contralateral interference level” --an
estimate of the true threshold.
Stenger Example at 1000 Hz
RE STIMULUS
INITIAL LE
STIMULUS
Delayed Auditory Feedback Tests
• Delayed speech test: Have pt talk while you play
back their own voice to them with a 200 ms delay.
Gradually raise level: when they hear their own voice,
they will change their speech (intensity, rate, fluency)
• Pure tone DAF (Tone Tap Test): Have pt tap out a
rhythm on a pressure transducer. Each tap will
generate a tone. Gradually raise level of tone: when
they hear the delayed tones, they will change their
pattern of tapping.
Varying Intensity Story Test
• Patient is asked to listen to a story in one ear, parts are presented
above the threshold and some parts are presented below the
threshold
• The story is presented so rapidly that it is difficult for listeners
to distinguish what they can admit to have heard and what they
should not
• The listener is then asked questions about the story
• The topic of discussion changes based on whether or not they
could hear the parts of the story presented below their threshold
– Information on china (dishes) is presented above threshold
– Information on China (the country) is presented below the
threshold and fits into the other story line, thus changing the
story topic if the patient is faking a hearing loss
Objective tests (AR, AEPs, OAEs)
• AR Өs at extremely low SL’s
– e.g., pure tone Ө of 60 & AR Ө of 80.
– SPAR: calculating audiogram from AR Өs
• AEP’s : objective Ө estimation
– Tests we’ve already discussed
– Auditory Steady State Responses (ASSRs)
• OAEs: measures of cochlear health
– Valuable in noise exposure cases in particular
Management of Patients with
Nonorganic Hearing Loss
• Once you have identified the problem:
– let them know you know
– shift blame onto your shoulders
• If they don’t come ‘round?...
– don’t report audiometric thresholds if you don’t
believe them
– In your report, be careful about the terms you choose.