105
Speech Intelligibility
STI-PA results screens
Models SE and DL
STI-PA modulation screen
In the
Modulation measurement screen
, the average decibel level over the run-
time in seven octave bands ranging from 125HZ to 8KHz with 14 frequencies is
displayed in a tabular format. These values are the signal to noise ratio
(accounts for any interfering background noise such as non-linear distortions,
electronics, reverberation, HVAC systems) in each attenuation band and
indicates which values are intelligible/unintelligible based on the CIS/STI scale.
NOTE: A high MTF value indicates that the listeners received the
message without any distortions or interference.
Figure 6-22: STI-PA Modulation screen
Table 6-4 defines the STI-PA: modulation frequencies for the seven octave
bands (per the IEC 60268-16 standard).
Table 6-5 defines the STI octave band with specific male and female weighting
factors used with STI-PA measurements (per the IEC 60268-16 standard).
Octave band Hz
125-250 500
1 k
2 k
4 k
8 k
First modulation
frequency Hz
1.00
.63
2.00
1.25
0.80
2.50
Second modulation
frequency Hz
5.00
3.15 10.0
6.25
4.00
12.5
Octave band Hz
125-250
500
1 k
2 k
4 k
8 k
Males
0.127
0.23
0
0.23
3
0.30
9
0.224
0.17
3
0.078
0.06
5
0.01
1
0.04
7
0.095
-
Females
0.117
0.22
3
0.21
6
0.32
8
0.250
0.19
4
0.099
0.06
6
0.06
2
0.02
5
0.076
-
LEQ
Average dB
level in band
Signal to noise ratio for each band
* Based on the CIS/STI scale ranging
from 0.00 – 1.00
Содержание SP-DL-1
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Страница 23: ...10 Detection Management Software DMS DMS Start Page Models SE and DL This page left intentionally blank ...
Страница 35: ...22 Turning off Navigating Models SE and DL This page left blank intentionally ...
Страница 69: ...56 Communications GPS Models SE and DL This page left blank intentionally ...
Страница 89: ...76 Back erasing Stopping a session Models SE and DL This page left blank intentionally ...
Страница 123: ...110 Speech Intelligibility STI PA results screens Models SE and DL This page left blank intentionally ...
Страница 137: ...AC DC output DC output 124 Models SE and DL This page left blank intentionally ...
Страница 149: ...Appendix A 136 Models SE and DL Block Diagram for SoundPro ...
Страница 161: ...Appendix B 148 Models SE and DL This page left blank intentionally ...