Scope
IEC 60268-16:2011
Speech Transmission Index Measurement
This test method provides an objective measure of speech intelligibility in acoustic environments using the Speech Transmission Index (STI) method. STI quantifies how well speech is transmitted through an acoustic space, accounting for noise, reverberation, and frequency distortion. The measurement is critical for evaluating communication effectiveness in public address systems, conference rooms, classrooms, and other speech-critical environments. Venues with high standards for speech clarity use this method to verify system performance and acoustic suitability. ISO 17025 accreditation ensures reliable assessment of speech intelligibility compliance with design standards.
What it measures
- Speech Transmission Index (STI) value (0-1 scale)
- Modulation transfer function across frequency bands
- Speech intelligibility rating and quality assessment
- Impact of noise and reverberation on speech clarity
- Communication effectiveness and auditory conditions
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DIN EN ISO 3382-2
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BS EN ISO 3382-2
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NF EN ISO 3382-2
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UNI EN ISO 3382-2
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UNE EN ISO 3382-2
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NEN EN ISO 3382-2
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DIN EN ISO 1996-2
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BS EN ISO 1996-2
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NF EN ISO 1996-2
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UNI EN ISO 1996-2
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UNE EN ISO 1996-2
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NEN EN ISO 1996-2
1,868
Accredited labs
20
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Showing 1,451–1,475 of 1,868 labs
DIN EN 60601-1
IEC 60601-1
DIN EN 60601-1-3
IEC 60601-1-3
DIN EN 60601-2-54
+ 3 more
Sigma-HSE (UK)
Active
DIN EN 13821
Sigma-HSE (UK) Ltd
DIN EN 14034-1
BS EN ISO/IEC 80079-20-2:2016
DIN EN 14034-2
+ 3 more
Sound power — engineering method using a
Kalibrierung von
250 N
Kraftmessgeräten
Kraftaufnehmer und 0,25 kN
+ 3 more
SoWiTec development
Active
IEC 61400-1
IEC 61400-12-1
IEC 61400-50
IEC 61400-50-1
IEC 61400-50-2
+ 2 more
Somerset Council
Active
(HSG 248) – 2021
R24 based on HSG 248
staining based on HSG 248
Sound Solution Consultants
Active
BS EN ISO 16283-1:2014+A1:2017BS EN ISO
BS EN ISO 16283-2:2020
BS EN ISO 140-4:1998
BS EN ISO 717-2:2020
ISO 1407
+ 1 more
ELECTRICAL CALIBRATION
DC RESISTANCE (continued)
DC Resistance
AC VOLTAGE (continued)
AC CURRENT
+ 3 more
based on BS EN ISO 6579-1:
ISO 21528-2
ISO 21149:2017+Amd1:2022
DIN EN ISO 18415
method based on BS ISO 16649-2:
+ 3 more
Verschlußzeit Kollagen/ADP
Kollagen/Epinephrin
Basophile Granulozyten
Eosinophile Granulozyten
Erythrozyten
+ 3 more
Verschlußzeit Kollagen/ADP
Kollagen/Epinephrin
Basophile Granulozyten
Eosinophile Granulozyten
Erythrozyten
+ 3 more
Speciality Steel UK
Active
ISO 3651-2
ASTM E 384-22
ASTM E10-23
ISO 6506-1
ASTM A262-15(2021) Practice E
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Spectra Analysis Services
Active
QOP01 based on HSG 248
(HSG 248) – 2021
(PCM) based on HSG 248
(HSG 264, 2012)
Appendix 5 of HSG 227 (2004))
AM01 based on BS EN ISO 4833-1:
AM03 based on BS EN ISO 11290-
AM05 based on BS ISO 21528-2:
AM08 based on BS EN ISO 15213-2:2023 by
AM12 based on BS EN
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SpineServ
Active
DIN EN ISO 9626
ISO 7206-13
ISO 7206-12
ISO 7206-10
ISO 7206-4
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Spratt & Hamer
Active
BS EN ISO 140-4:1998
ISO 13829
BS EN ISO 717-2:2020
ISO 1407
BS EN ISO 9972:2015
+ 1 more
Springfields Fuels
Active
LMM2149, ASTM E112-13 by
ISO 6507-1
LMM2207, ASTM E112-13 by
LMM1862, ASTM E112-13 for
to BS EN ISO 6507-1:2018
+ 3 more
FM003 based on ISO 6888-
FM004 based on ISO 16649-2:2001
FM006 based on ISO 6579-1:2017+Amd 1:202
FM009 based on ISO 11290-1:2017
2) WM005 based on ISO 9308-2:2012 using
+ 1 more
DIN EN 772-16
BS EN ISO 10545-2:2018
DIN EN 1344
DIN EN 12953-8
DIN EN 16510-2-4
+ 3 more
DIN 38402-A 13
DIN EN ISO 5667-6 (A 15)
DIN EN ISO 5667-1 (A 4)
DIN EN ISO 5667-3 (A 21)
DIN 38404-C 4
+ 3 more
Kraft
Vibration measuring instruments — requir
Sound power — survey method (ISO 3746)
1 kN
Railway brake — automatic variable load
+ 3 more
Großes Blutbild
Kleines Blutbild
Erythrozyten
Hämoglobin
Hämatokrit
+ 3 more
ISO 7171
ISO 1407
BS EN ISO 140-4:1998
BS EN ISO 717-2:2020
Starna Scientific
Active
Sealed liquid cells containing
prepared from NIST SRM 935a
Toluene/Hexane
Neutral density glass filters
Neutral density glass filter
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