NTi Audio Acoustilyzer AL1 - Manual (Page 58)

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d. STI-PA Post Processing
Measuring speech intelligibility index in realistic environment conditions
is often not applicable, e.g. playing the test signal in a railway station at
emergency levels during peak hours will irritate passengers. Additionally,
at rush hours the characteristics of background noise is likely to be highly
impulsive, while a prerequisite for accurate STI-PA measurements is a
negligible impulsivity in the background noise.
Under such circumstances the STI-PA measurement should be shifted to
a more suitable time of the day, e.g. at night. Such STI-PA measurements
taken with atypical background noise conditions have to be post-processed.
Post processing combines the STI-PA measurement data taken with quasi
noise-free ambient conditions with the unweighted octave band noise levels
(Leq) taken e.g. during day time with realistic environmental conditions.
The NTi Audio STI-PA Post Processing Software is exactly tailored for this
application e.g. to combine the night and day time measurements.
“STI-PA_PostProcessing.xlt” is available
• For download at www.nti-audio.com, Products, Minstruments,
Acoustilyzer AL1, Downloads
• On the CD “MiniLINK - PC Software”
Note: When opening the post processing sheet all macros have to be
activated.