Maico MA 42, Руководство по эксплуатации

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Operation Manual MA 42
8100460 Rev.7 Ver.1 19 12/15
to present or interrupt the tone. The status LED above the Stim button will
flash when the tone is presented.
Follow your preferred procedure for the evaluation of the hearing threshold.
Note: A warning prompt appears on the display in the event that the hearing
level exceeds 100 dB
HL
. The warning prompt disappears after approximately 1
second. As long as the prompt is visible on the display, no further entries can
be made.
Once a threshold value is established, press the Store (3) key in order to store
the threshold. The appropriate symbol will be plotted on the audiogram.
If the patient is not responding, the current value can be marked as “no
response” by holding the store button pressed for 3 seconds. Once all
frequencies are tested, choose the poorer ear and repeat the hearing
threshold test.
Pulse Tone
If required, the test can also be performed with a pulsed tone. Set the test
signal button (12) on Pulse and the pure tone will be switched to a pulsing
tone.
Warble Tone
If required, the test can also be performed with a warble tone. Press the
button (12) and the pure tone will frequency modulate. The warble tone can
also be pulsed by selecting P & W (12).
Noise
The signal may be changed from a pure tone to narrow-band noise or white
noise by pressing the signal key (11), (15) underneath the display, whichever
one corresponds to the current test channel. This will change the status
displayed in the test channel from “Tone” to “Noise.”
6.1.1.1 Masking
Masking is required if there is a notable threshold difference between the left
and right ears. It is possible for sound to be transmitted to both ears via bone
conduction while testing the poorer ear. This is called “crossover.”
Crossover occurs often while testing bone conduction, but it can also occur
during air conduction testing. Relevant to crossover is the sound level received
by the opposite ear. The difference between the original test signal in the test
ear and the received signal in the opposite ear is called “interaural
attenuation.”