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response only when he/she hears the output stimulus. As a stimulus, pure tones at dierent frequencies
sent in continuous, pulsed (presentation frequency 2 Hz), lot (presentation frequency 1 sec mode, ON=200
msec, OFF=800 sec) are used. The increment of the output stimulus will be continuous and with variable
speed (1 dB/sec, 2.5 dB/sec, 5 dB/sec). The frequency variation can be xed (frequency steps in octaves),
or continuous (frequency sweep). It will also be possible to select the presentation sense of the stimulus:
from high to low frequency or vice versa. The overall exam time can be between 30 to 60 sec. for the xed
presentation mode and 60 sec. for the sweep mode.
Once inside the test page, use the following commands for the dierent settings:
For stimulus presentation mode (continuous, pulsed, lot) use F1.
To increment speed of the stimulus press F4>F5 then F5 for variations.
For the frequency variation (xed or sweep) press F4>F5 then F4 to choose.
For the presentation sense (low>high or high>low) press F4 then F3 to choose.
For test duration (30sec or 60 sec) press F4>F5 then F6 to choose.
Test GAP (Gap Detection Threshold)
Gap detection testing can be done several ways, but the premise is to introduce two stimuli (tones,
clicks, broad band noise) of some duration with a variable gap between them.
The subject is to identify when the temporal gap when the two stimuli are heard as one sound or two.
The threshold at which the gap is suciently wide to be heard as two sounds is the ‘’gap detection
threshold.’’ Research on speech perception indicates that persons should be able to hear transitions
of formant frequencies of speech in the 0 to 20 millisecond range, so that the assumption is that
gap detection thresholds greater than 20 milliseconds are abnormal and a temporal processing
disorder may be present. The greater the gap detection threshold, e.g. up to 300 msec, the greater the
probability that a person will have diculty with speech discrimination.
To change the GAP use F1 softkey or
left
and
right
(10) arrow keys.
To change the Rate use F2 softkey.
To perform the test set CH1 stimulus (WN or SN) at a comfortable level and press START/STOP (16).
Patient should press the patient push button if he can recognize the GAP. At the end of the test a
score will be automatically calculated based on heard stimuli percentage; the value can be stored by
pressing STORE (17) key.
Test DLF (Dierence Limen for Frequency)
The minimum detectable change, or dierence limen, of frequency of pure tone (DLF) is a fundamental
limit of frequency resolution and is, hence, an important criterion to examine general theories of
hearing. There have been two common ways of measuring frequency discrimination. One involves the
presentation of two successive steady tones with slightly dierent frequencies. The subject is asked
to judge whether the rst or the second had the higher frequency. The order of the tones is varied
randomly from trial to trial, and the DLF is usually taken as that frequency separation between the
pulses for which the subject achieves a certain percentage of correct responses.
A second measure uses tones which are frequency modulated (FM) at a low rate (For example:
5Hz modulation frequency with a 500-Hz carrier). Usually, two successive tones are presented, one
modulated and the other unmodulated. The amount (or depth) of modulation necessary for detection
is determined.
To set the stimuli frequency variation use F1 softkey.
To set stimuli presentation rate use F2 softkey.
To perform the test set CH1 stimulus at a comfortable level and increase the DLF percentage until the
patient can perceive the difeerence between the two frequencies. The value can be stored by pressing
STORE (17) key.
Quick SIN Test
Quick SIN is a speech-in-noise test used to quickly evaluate patient capability to understand speech in
noisy environment. This capability can not be determined through the standard speech audiometry
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