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Step 2: Measure
Note that for simultaneous binaural measurements, Audioscan recommends
that the client is a distance of 45–60 cm (18–24 in.) from the loudspeaker.
All measurements use the signal type selected in step 1: Setup. Each
sequence of measurements is preceded by a sound field equalization burst.
In on-ear mode, the instruments will mute automatically prior to the sound
field equalization burst. This ensures that, when the instruments are
automatically unmuted, the subsequent measurements are accurately
calibrated because the soundfield calibration was not affected by acoustic
leakage. This method is suitable for both open and closed fittings, but it is
important that your client remains still during each measurement sequence.
For test box mode, the instruments are not muted during the sound field
equalization burst as the venting is occluded upon attachment to the coupler.
Open fittings cannot be verified in test box mode.
In the Measure step, there are two ways of performing verification
measurements: Automatic and Manual.
Automatic: measures the current instrument output, automatically adjusts
it to match the prescribed target, and then performs another measurement to
confirm the target match.
a.
The automatic measurement process is carried out at 65 dB by default
and you can select additional levels (50 dB and 75 dB). Gain adjustments
are based on the 65 dB measurement.
b.
If performing on-ear measurements, instruct your client to face the
loudspeaker and to remain still during each sequence of measurements.
c.
Click Start on the relevant side to measure one side. Click Both to
measure both sides (binaurally). Binaural measurements take place
simultaneously if using Genie 2 | 2019.2 and Verifit2 with software
version 4.18 or later. Otherwise they take place sequentially.
d.
When doing simultaneous binaural measurements, if the signal reaching
left and right reference microphones is not equal, e.g. due to the client
not facing the speaker, the measurement will be paused and Verifit2’s
Binaural Sound Field Assist tool will show instructions on the Verifit2
screen to help balance the signal reaching left and right.
e.
The test signal will turn off automatically when the measurements are
complete. If you need to stop the measurement prior to completion,
click Stop.
f.
If you are satisfied with the measurements, proceed to step 3: Finish.
If you want to perform further fine-tuning, repeat the automatic
measurement, or click the Manual tab to perform a manual measurement.
Note that if you repeat the automatic process immediately, an initial
measurement will not be done.
