GSI AudioStar Pro™ Clinical Audiometer
76
D-0100778 Rev C
Special Test Procedures - More Test Type button
The AudioStar Pro may be configured to perform many audiologic evaluations
for further diagnosis, to rule out the presence of malingering and for research
purposes. This section describes special test procedures that have been optimized
for use with the GSI AudioStar Pro audiometer.
Pressing the “More” test type button calls up a menu of special tests. Use the on-
board navigation buttons or an external mouse to select the desired special test.
Alternate Binaural Loudness Balance (ABLB) or Fowler Test
The perceived growth of loudness of a supra-threshold tone in an impaired ear
may differ from the compared growth of loudness of a tone of identical
frequency in the normal ear. Recruitment, if present, may be found.
Determine the threshold level for each ear at all frequencies being tested.
Select the ear to serve as the reference ear, typically the ear with the
better hearing sensitivity. This ear will receive the tone at a fixed
intensity.
Select ABLB from the More Test Menu.
Set the intensity of the tone for each channel to 20 dB above the
threshold of each corresponding ear.
The tone will automatically alternate from Channel 1 when the interrupt
function in channel 1 is in the on position or manually, by pressing and
holding the presentation bar in channel 1.
The tone alternates at the rate of 400 msec on, 400 msec off followed by
Channel 2 at 400 msec on, 400 msec off.
Keeping the intensity fixed in the reference ear, vary the intensity level
of the tone presented to the test ear. Record the level at which the patient
judges both of the signals to be of equal loudness.
Repeat the above procedure increasing the intensity of the reference ear
by 20 dB each time until an intensity of 80 or 90 dB is reached. Identify
the dB HL of the tone necessary to “balance” in loudness the tone in the
reference ear at each level. This procedure is followed for the each
frequency to be balance tested.
To increase the test reliability, the patient should be given several trials
to judge whether a variable tone is “softer,” “equal to,” or “louder” than
the tone in the reference ear.
