Interacoustics AT235 Additional Information

AT235 Additional Information Page 21
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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.
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The table shows which reflex decay will be tested. Selecting the bottom row enables the addition of
a new decay stimulus. Hold the button while selecting with the wheel the
stimulus to be added. Note that rotating down gives ipsilateral stimuli and rotating up gives
contralateral stimuli. The table below shows which stimuli are available depending on the probe
tone frequency and which side you are measuring. 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.
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To select a reflex sequence from the table, hold the button while rotating the
wheel for changing the stimulus type. Press the button in order to remove the
reflex sequence from the table.

Interacoustics AT235 Specifications

General

Brand	Interacoustics
Model	AT235
Category	Measuring Instruments
Language	English