NTi Audio Acoustilyzer AL1 - Manual (Page 55)

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b. How to measure
• Select the STI-PA function.
• Monitor the actual sound pressure level
of your environment on the Acoustilyzer
display.
Preconditions:
• To avoid measurement failures the
STI-PA test signal level should be
at least 60 dBSPL.
• The STI-PA measurement should be
carried out in simulated emergency
conditions (same sound pressure level
and all components activated).
• No impulsive noise events should occur
during the 15 seconds measurement
time.
NOTE: Even intermittent noise may affect
the STI-PA test result.
Signal Source:
The NTi Audio TalkBox can simulate a
human talker at normal and emergency
speaking levels, enabling the measurement
of the complete system including the
acoustic signal to the microphone
(directivity, room characteristics, etc). Place
the NTi Audio TalkBox at the typical human
speaker position.
The Minirator MR-PRO or a CD Player (with
the NTi Audio CD “STI-PA V1.1” or higher)
can be used for electrical signal injection for
system tests without the microphone.