NTi Audio XL2 Sound Level Meter - Manual (Page 118)

118
STIPA
1 Run Indication
This icon displays the run status of the STIPA measure-
ment.
2 Measurement Result
Single value speech transmission index result. •
Repeatability of measurement result: •
Since a dedicated noise test signal is used, the STIPA
result may deviate by maximum 0.03 STI (=Max-Min) at
the same measurement position.
3 Sound Level LAeq
Shows the time-averaged sound level of the 15 seconds
STIPA measurement cycle time.
4 Sound Level LAS
Actual sound pressure level.
5 Analog STIPA Bargraph
Bargraph display and interpretation of the speech intelligi-
bility measurement result
Exlnt 0.75 - 1.00 STI •
Good 0.60 - 0.75 STI •
Fair 0.45 - 0.60 STI •
Poor 0.30 - 0.45 STI •
Bad 0.00 - 0.30 STI •
6 Qualification Scale
The STI value is shown as a letter of the qualification scale
below, which informs about the typical STI requirements
for dedicated applications.
Band STI Range Examples of typical uses
A+ > 0.76 recording studios
A 0.72 - 0.76 theatres, speech auditoria,
parliaments, courts
B 0.68 - 0.72 theatres, speech auditoria,
parliaments, courts
C 0.64 - 0.68 teleconference, theatres
D 0.60 - 0.64 class rooms, concert halls
E 0.56 - 0.60 concert halls, modern churches
F 0.52 - 0.56 PA in shopping malls,
public offices, cathedrals
G 0.48 - 0.52 PA in shopping malls,
public offices
H 0.44 - 0.48 PA in difficult acoustic
environments
I 0.40 - 0.44 PA in very difficult spaces
J 0.36 - 0.40 not suitable for PA systems
U < 0.36 not suitable for PA systems