Download Lesson 2 History of Hearing Testing

HISTORY OF HEARING
TESTING
Audiology
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Audio - Latin…to hear, pertaining to hearing
Logy - Greek…logus…science
Therefore the science of hearing and hearing
disorders
Facets of audiology
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Discovery
Evaluation
Rehabilitation
Lineage of Audiology
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Originated during and just after WW II (194546)
Originally audiologists were SLP’s or ENT’s
Father of Audiology is Raymond Carhart (he
and Norton Canfield coined the term
“audiology
Reason for the field of Audiology
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The government became concerned with hearing disorders
when VA hospitals had military with hearing problems due to:
-direct injury—gunshot, shrapnel
-disease—jungle rot
-acoustic trauma—high intensity noise (cannons,guns,etc)
-emotional disorders - “shell shock” (protective device)
Aural rehabilitation hospitals opened all over the nation and were
interested in:
-conservation of hearing
-habilitation and rehabilitation programs
-diagnosis (Dx) of hearing loss related to medical
problems
-educational placement and programs for the hearing impaired
Academic Qualifications for Audiologist
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BA/BS in Communicative Disorders or equivalent
MA/MS in Audiology
Pass national written examination (formerly NESPA)
Complete Clinical Fellowship Year (CFY)
Certificate of Clinical Competence in Audiology
(CCCA)
State License (usually CCCA + fees)
Au.D. or equivalent will be needed by 2007
Ph.D. and FAAA is optional at this time
Other Hearing Health Professionals
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Otolaryngologist
Hearing Conservationist
Hearing Aid Specialist
Audioprosthologist
Audiometrist
Professional Opportunities for
Audiologists
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Teaching
Clinical
Research
Administration
Hearing Tests and their Development
(non-audiometric)
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Watch tick
Coin-click
Conversational voice
Noise makers
Tuning fork tests (Demonstrate using tuning fork)
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Schwabach Test (also called the time threshold test)
Rinne Test
Bing test
Weber
Pure Tone Audiometry
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Normal hearing (intensity) = 0—25dB (ANSI)
We hear 20—20,000 Hertz (frequency)
We only test 250—8,000 Hertz (Hz)
250, 500, 1000, 2000, 3000, 4000, 6000 & 8000Hz are the
individual frequencies at which we test by AC
250, 500, 1000, 2000 and 4000Hz are the frequencies for BC
Quiet environment needed (otocups, insert phones and booths
Occlusion effect—the increase of loudness of pure tones at 1000
Hz or lower. Happens in normal, sn—not in conductive losses.
Sweep check vs. threshold testing
Otoscope
Performing the Pure Tone Test
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Check calibration of audiometer
Otoscopic inspection (wax, collapsed canal,
drainage etc.)
Patient instructions
Question: Which is your better ear?
Hairdos, wigs, glasses and earrings
Correct placement of earphones (TDH 39)
Correct placement of the patient
Performing the Pure Tone Test
(continued)
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Pulsed or continuous signal
Present tone with about 1 second duration
Be aware of eye contact
Watch out for “rhythm system”
Red, right, round. Blue X’s for left (AC)
Bone conduction (BC) thresholds and
symbols
Masking for AC and BC
Maximum output at each frequency
Patient Responses
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False negative
False positive
Validity vs. reliability
Down 10; up 5 rule
Determine threshold
Test re-test reliability
Pure tone average (PTA)
Tactile responses (cutile)
Cross hearing and interaural attenuation (IA) AC & BC
Masking
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Narrow band
White noise (broad band or wide band noise)
Effective masking
Over masking (OM
Speech noise
Complex noise
Other masking (saw tooth, pink noise etc.)
Plateau Method
Calculation of Percentage of Hearing Loss
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Average thresholds at 500, 1K, 2K and 3KHz
Subtract 25 dB
Multiply X 1.5 for each ear = % of loss per
ear
Binaural loss %’age = better ear X 5 + poorer
ear %age divided by 6 = binaural percentage
loss
Audiograms
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Table audiogram
Graph audiogram