Maintenance
31
4.3.3. Calibration of Stimulus Intensity within Free
Field
The placing of equipment for calibration of stimulus intensity within free field is shown
in Fig. 21.
Fig. 21. Equipment placement during calibration
Designations shown in Fig. 21:
1 — acoustic system,
2 — sound level meter.
The calibration of stimulus intensity within free field is performed at the spot using
a sound level meter. The acoustic system (stimulator) is placed within 1 meter from
the estimated patient’s head center on a special support located at the head level
(with azimuth of 0°, i.e. straight before the patient). The sound level meter microphone
is positioned at the proposed head center. The room acoustics should conform
to the requirements for free field audiometry. The room and its interior should provide
free wave transmission without any reflections. It should also be free from reflected
and stationary waves.
During the operation the volume knob of the acoustic system should be set
to maximum, and the bass/tone knobs should be at mid-position. The acoustic system
is powered via isolation transformer.
During the calibration follow the steps below.
Run the
Neuro-Audio.NET
program. In the main menu select
Setup|Calibration
mode…
Enter the password for the setting/calibration mode (see section
4.2 “Calibration mode in
Neuro-Audio.NET
software” of “Neuro-Audio” calibration
guidelines).