natus Madsen A450, Руководство пользователя

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For detailed examples of audiometric testing, see the Madsen A450 Reference Manual.
1. Select the Speech screen in the Otosuite Audiometry module.
2. If needed, click the Scoring and Playing icon to set up word or phoneme scoring.
3. Prepare the patient. If you wish to instruct the patient after you have placed the transducers on the head of the
patient, you can use the
Talk Forward
button. You can talk to the patient to adjust the patient communication levels
when
Talk Forward
is active.
4. In the Control Panel, select test conditions for ear, transducer, unmasked/masked, and test type.
5. Select the stimulus level with the Up/Down arrow buttons (or on keypad).
6. Select speech input signals.
You can choose from either microphone input or recorded input source. Combining recorded
Source A
and
Source B
as
Input
sources in the
Test Options
section of the
Control Panel
will replace the audiometer speech masking with a
recorded input.
7. Select your speech input from the right-click menu in the control panel.
–
Int. CD
(CD material in CD/DVD drive)
– File (integrated Otosuite Speech Material or regular sound files)
–
Line In
(analog input from external sound players, e.g. CD, MD, MP3 or cassette recorders connected to the audi-
ometer via the
Line In
input).'
Note
•
If an external playback device is used to generate speech stimuli via the line input, care must be taken to
ensure that the player has a flat frequency response in the range 125 Hz to 6300 Hz. The maximum allowable
deviation from the average response level is +/-1 dB; the average response level should be measured over the
range 250 Hz to 4000 Hz.
The headset microphone is ready for use and does not require calibration or equalization procedures. The headset
microphone should be turned to a position just below the operator’s mouth.
If an external playback device is used to generate speech stimuli via the line input of Madsen A450, only a high
quality CD player or similar device should be used; tape recordings may not provide a sufficient signal to noise
ratio. Preferably, the external device should deliver its output via a fixed-level line out connector. The input gain
on Madsen A450 should be adjusted to obtain a 0 dBVU reading when the calibration signal is played by the
external device.
8. You can find speech material files in the
File/track/list selection
drop-down list.
Madsen A450 19
13 Performing speech audiometry