Routine Test Procedures
The following procedures are in compliance with the current ANSI and ISO
recommendations for Manual Pure Tone Threshold Audiometry.
Patient Instructions
Preparing the subject for test:
1. Put the subject at ease.
2. Make sure the subject understands the task.
3. Use the following instructions:
“I am going to place these earphones over your ears. You will hear tones or
beeping sounds which may be loud or soft. Whenever you hear, or think you
hear, one of these tones, raise your hand. Lower your hand when you no longer
hear the sound. Remember, raise your hand when you hear the tone and lower
your hand when you do not.”
Patient Familiarization
•
Familiarize the subject with the test and determine the start point.
•
Start with the “better” or
RIGHT
ear.
•
Demonstrate a tone for the subject using 1,000 Hz at 50 dB HL.
•
If the subject responds, repeat at 40 dB.
•
If the subject responds again, this is the “
start
” point.
NOTE:
Discomfort of the patient could lead to inaccurate results. The operator is
to evaluate the environment and physical conditions to determine whether these
factors may affect the examination and give discomfort to the patient.
Threshold Determination (Pure Tone): Modified Hughson-Westlake
•
Present the tone at 50 dB.
•
Present the tone for 1 or 2 seconds. The time between the tones should
vary, but should not be shorter than the test tone.
•
With each response, decrease the tone 10 dB until the first “No
Response” occurs.
•
When the subject does not respond to a tone, increase the hearing level
by 5 dB until a response occurs.
•
Continue with
DOWN
10 dB,
UP
5 dB until the threshold is reached.
NOTE
: Threshold = minimum dial setting at which a response occurs 50% of the
time.
•
The threshold is considered to be the minimum hearing level at which a
response has occurred two out of three times at lowest db HL. Record
this setting by pressing Store.