Interacoustics AA222 Additional Information page 32

AA222 Additional Information
4.2.2.4 Reflex latency
Select a reflex latency test in your Protocol settings. By rotating the wheel, you can change the following
settings.
A Auto run. When enabled, the test will run automatically as part of the protocol.
Show warning gives you the opportunity to set a level at which the AA222 gives a warning.
B
C Measure latency at ambient pressure allows you to measure reflex latencies while the tympanic
peak pressure is being disregarded. When checked, measurements are performed at 0daPa.
D 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 asks 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.
E 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.
At Scale you choose the maximum values of the y-axis on the reflex graph.
F
G 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.
H The table shows which reflex latency will be tested. Selecting the bottom row enables the addition of a
new latency 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.
I
When a reflex latency is selected from the table, hold the
change the stimulus type. Press the
table.
button while rotating the wheel to select the stimulus you
button in order to remove the reflex sequence from the
button while rotating the wheel, to
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