otometrics madsen itera ii, Reference Manual

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6 Tone testing
6.1 Air Conduction threshold test
Modified (ascending) Hughson-Westlake.
Prerequisites
• Press
TONE
.
• Press
AC
.
• If needed, select
WARBLE
or
PULSE
as stimulus type(an advantage when you test children).
• If you want to predefine the duration of the signal presentation when you press the
INT
button, press
IMPULSE
.
• If you wish to use masking, select the masking type: Press
MASK ON
. See also Testing with masking
►
64 .
• If required, turn the
FREQUENCY
knob to set the starting frequency: The typical starting frequency is at 1000 Hz.
The signal is usually presented for each tone in the following order:
1000 Hz and increasing frequencies
followed by
1000 Hz (cross check) and decreasing frequencies.
• Set the initial level of the presented signal to an audible level: Turn the
LEVEL
knob to 40 dB HL.
This is to familiarize the patient with the test signal. Other familiarization procedures may be preferred.
• Test the better ear first. If this is unknown, start with the right ear. Press
L<-->R
to select the ear you wish to test.
• Give the Patient Responder to the patient and explain how it should be operated (see The patient responder ► 54 ).
6.1.1 Testing
1. Press the
INT
button (right or left) to present the tone to the patient for 1 to 1.5 seconds.
2. Use the corresponding LEVEL knob to set the intensity to approx. 20 dB above the patient's presumed threshold.
If the patient does not respond to the presented signal, turn the
LEVEL
knob to increase the signal level in steps of
10 dB until the patient responds.
3. Reduce the signal level by 20 dB until the patient does not respond to the signal.
4. Increase the signal level in steps of 5 dB and present the signal to the patient at each level until the patient responds
to the signal.
5. Reduce the signal level by 10 dB and present signals at levels increased by 5 dB until the patient responds.
6. Repeat item 5 , 1 to 3 times until the patient has responded 3 times at the same level.
This level represents the hearing threshold at 1000 Hz based on 3-5 ascending series.
In some situations, it may be satisfactory with two responses at the same level.
If the patient has responded less than 3 times at the same level after 5 series, present a signal at 10 dB above the level
where a response was last registered.
Then repeat item 6 .
7. When the threshold is determined, press STORE to store that particular threshold. See Store/toggle threshold status
► 23 .
8. Select the next frequency.
You can link the Store and Next Frequency functions, so that the test progresses with the next frequency when you
press
STORE . See SETUP items ► 89 .
Otometrics - MADSEN Itera II 61