Pure Tone Audiometry Flashcards
What are the parts of the pure tone audiometer?
- power: on/off
- test type
- stimulus
- transducer
- frequency selector dial
- attenuator
- interrupter
What is the principle objective of pure tone audiometry?
to determine the sensitivity of the human auditory system
What is reliability?
is the test repeatable?
what is validity?
does the test measure what it is supposed to measure?
What are the four ways the test could turn out?
- true positive
- true negative
- false positive
- false negative
What does the Clinical Decision Analysis (CDA) do?
it asks questions about each test’s sensitivity, specificity, efficiency, and predictive value
What is the Clinician’s Role in Pure Tone Audiometry?
- provide clear instructions
1. tell client purpose of test
2. tell client what they will hear
3. tell client what to do when they hear the stimulus
4. tell them to stop doing whatever behavior you requested in step 3 when tone goes away - perform test accurately
What is the patient’s role in manual pure tone audiometry?
yield a behavioral response to the acoustic stimulus; raise hand, drop toy in bucket, etc.
What is a Threshold?
the lowest signal intensity at which multiple presentations are detected 50% of the time
What are the extrinsic factors that affect pure tune threshold variability?
things in the physical environment: temperature, lights, ambient noise
What are the intrinsic factors that affect pure tone threshold variability?
neurophysiological factors and subject motivation
What is ASHA’s 1978 procedure?
- Begin at 1000 Hz in the right ear, or the better ear
- Present tone at 30 dB HL. If no response is obtained, raise to 50 dB HL
- If there is no response, continue to raise the stimulus in 10 dB steps until a response is obtained or until the limit of the audiometer is reached
- after a response is obtained, lower the level of the tone in 10 dB steps
- each time a tone is introduced, it is maintained for one or two seconds
- all ascending movements of the hearing level dial from this point on are made in 5 dB steps
- When a tone is lowered below the patients response level, it is then raised in 5 dB steps until it is audible again, then lowered in 10 dB steps and raised in 5 dB steps until the 50% threshold response criterion has been met
What is an Audiogram?
a chart or graph that shows the hearing level on the ordinate lines and the frequency of the stimulus tone on the abscissa
Red Circle
right ear, unmasked, AC
Red Triangle
right ear, masked, AC
Blue X
left ear, unmasked, AC
Blue Square
left ear, masked, AC
Red
right ear, unmasked, BC
Red [
right ear, masked, BC
Blue >
left ear, unmasked BC
Blue ]
left ear, masked BC
Blue S
sound field
Blue A (underlined twice)
aided responses
Red O with arrow
air conduction responses for the right ear not observed at the limits of the audiometer
Blue CI
responses with a cochlear implant
PTA: -10 to 15
None/ Within Normal Limits