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A way to avoid the bias described above and to increase angular sensitivity is to place the microphones
not in your ears but at the ends of a ruler or yardstick with the head-top attached in the middle. Rotate
the ruler according to the pilot tones and log the results.
Logging azimuth during PRIR measurement
The pilot tone procedure can be used as part of the PRIR measurement process.
Pressing
MENU-SPOS
causes the screen to say:
>USE DURING SPK:NO
Set
USE DURING SPK
to
NO
for the pilot tone and
SPK
(PRIR) procedures to be separate (default).
Set to
YES
to combine them. If combined, the subject will hear the pilot tones immediately after the
announcer’s voice has said “Look centre”, “Look left,” “Look right.” Once the listener has aligned the
head with a speaker using the tones,
OK
is pressed and the PRIR measurement process continues.
This method is particularly valuable in
ALL
and
LR
measurements in which there is no real centre
speaker and a virtual centre speaker is created. The virtual centre is a copy of the looking-right
measurement of the right real speaker. The pilot tones will ensure that the head is properly centred on
the right speaker during that sweep, thus creating a properly positioned virtual centre speaker.
