Hugson-Westlake Auto-Threshold Test (Air Conduction) - Resonance R07A Benutzerhandbuch

4.2 Hugson-Westlake Auto-threshold (AC)
The test, controlled by the patient's pushbutton according to the Hughson-Westlake method, pro-
vides a modified and abbreviated version of the ISO 8253-1 standard for recording automatic AC
threshold without masking.
This test is especially used for industrial audiometry and hearing conservation programs.
Hughson Westlake is an automatic pure tone test procedure. Threshold is defined as 2 out of 3 correct
responses at a certain level in a 5 dB increase and 10 dB decrease test procedure. The Hughson West-
lake method is used to obtain pure tone thresholds automatically.
How perform the test: Test patient must be instructed to keep his/her pushbutton pressed as long as
he perceives the tone and release it as soon as the tone is no longer heard.
To activate the Auto-threshold test please refer to paragraph 5.2 Setup menu.
Once activated, entering the Menu you can select the test pressing F2.
The screen will display the test interface.
Familiarisation
Before starting the test, you can perform a familiarisation to train the patient.
Use the buttons as described on the paragraph 3.2 to act the familiarization process: present a tone
at 1000 Hz which can easily be perceived (i.e. 50 dB) If necessary, increase with steps of 10 dB until the
tone is clearly perceived.
If the familiarisation process is successfully completed, you can start the test pressing F1.
Threshold Determination
The hearing threshold is defined as the lowest level at which at least 50% of the stimuli elicit a re-
sponse. This threshold is found by the following procedure.
1) Present a tone which is 10 dB lower than the level at which familiarisation was finished.
2) Decrease the level in steps of 10 dB until response fails.
3) Increase the level in steps of 5 dB until the subject responds again.
4) Repeat 2) and 3) two or three times until the threshold appears at the same level to at least 50% of
presentations.
The time intervals in between the stimuli should be varied to prevent the patient predicting a pattern
to the stimulations.
5) Change to the next frequency and repeat the procedure until all frequencies are measured. Repeat
the procedure at 1000 Hz. If the difference to the previously found threshold is then 5dB or less pro-
ceed to test the other ear. If the difference is 10 dB or greater, repeat the test at the other frequencies,
until agreement within 5 dB has been obtained.
6) Proceed until both ears have been tested.
Once completed the test, store the results pressing F2.
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