Interacoustics AA222 Additional Information page 31

AA222 Additional Information
4.2.2.3 Reflex decay
Select a reflex decay test in your Protocol settings. By rotating the wheel, you can select and change the
following settings.
Auto run. When enabled, the test will run automatically as part of the protocol.
A
B Test duration sets the length of the probe tone to 10, 15, 20, 25 or 30 seconds.
C Show warning gives you the opportunity to set a level at which the AA222 will give a warning.
D Measure decay at ambient pressure allows you to measure reflex decay while the tympanic peak
pressure is being disregarded. When checked, measurements are performed at 0 daPa.
E Set stimulus level allows you to set the stimulus level to either Manual or Automatic. Manual
means that prior to the test, a pop-up window will ask you to set the stimulus level. When choosing
Manual it is recommended to have Show warning off. Otherwise, you may be asked twice to set the
stimulus level when it exceeds the warning level. Automatic means that the AA222 sets the stimulus
level 10 dB above reflex threshold level. If that stimulus level exceeds the warning level or cannot be
obtained, you will still be asked to set the stimulus level manually.
F Display reflexes as either Positive or Negative makes the reflex curve flip over the x-axis. When
Positive is chosen, you can normally expect the deflection to go in a positive direction.
G At Scale you choose the maximum values of the y-axis on the reflex graph.
H When the AGC (automatic gain control) checkbox is marked, the size of the ear canal is taken into
account for adjusting the stimulus level. Without compensation, the intensity level will increase as the
size of the ear canal decreases. Note that current tympanometry standards do not yet describe how
AGC should be applied. We recommend that AGC is used when testing infant ears, as, theoretically,
with ear canal volumes smaller than 0.2 ml, the stimulus level can be increased by 20 dB or more. The
AGC is applied for both the ipsilateral and contralateral insert.
I The table shows which reflex decay will be tested. Selecting the bottom row enables the addition of a
new decay stimulus. Hold the
wish to add. Note that rotating down gives ipsilateral stimuli and rotating up gives contralateral stimuli.
NB stands for narrow band noise. LP stands for low pass filtered noise which has a spectrum from 400
Hz up to 1600 Hz. HP stands for high pass filtered noise which has a spectrum from 1600 Hz up to 12
kHz. WBN stands for wideband noise which has a spectrum from 400 Hz up to 12 kHz.
J
To select a reflex sequence from the table, hold the
change the stimulus type. Press the
table.
button while rotating the wheel to select the stimulus you
button while rotating the wheel, to
button in order to remove the reflex sequence from the
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