TECHNICAL INFORMATION / INSTALLATION INSTRUCTIONS
AMF SOUNDMOSAIC
TV_701e 09-2007
Sound Mosaic
2
SPEECH INTELLIGIBILITY
The required intelligibility of speech has considerable influence on the lay-out and number of
loudspeakers needed. The objective is the constant intelligibility of sound and syllables also
over some distance.
A crucial criterion constitutes the so-called STI-Index:
STI
:
Speech Transmission Index
Measure of speech intelligibility of syllables, words and whole sentences.
A minimum rate of STI> 0.45 should be achieved. Differences are perceived most intensely
between 0.4 and 0.5.
STI-value Classification
according to EN
60268-16
Intelligibility of
syllables
[%]
Intelligibility
of words
[%]
Intelligibility
of sentences
[%]
1.00…0.75 excellent 96…91
96…94
96
0.74…0.61 good 90…68 93…88 96…95
0.60…0.45 adequate 67…49
87…78
95…93
0.44…0.31 weak 48…35 78…68 92…90
0.30…0 bad 34…0 67…0 89…0
Image 4
