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
๐Ÿ‡ฉ๐Ÿ‡ช DIN EN ISO 3382-2 ๐Ÿ‡ฌ๐Ÿ‡ง BS EN ISO 3382-2 ๐Ÿ‡ซ๐Ÿ‡ท NF EN ISO 3382-2 ๐Ÿ‡ฎ๐Ÿ‡น UNI EN ISO 3382-2 ๐Ÿ‡ช๐Ÿ‡ธ UNE EN ISO 3382-2 ๐Ÿ‡ณ๐Ÿ‡ฑ NEN EN ISO 3382-2 ๐Ÿ‡ฉ๐Ÿ‡ช DIN EN ISO 1996-2 ๐Ÿ‡ฌ๐Ÿ‡ง BS EN ISO 1996-2 ๐Ÿ‡ซ๐Ÿ‡ท NF EN ISO 1996-2 ๐Ÿ‡ฎ๐Ÿ‡น UNI EN ISO 1996-2 ๐Ÿ‡ช๐Ÿ‡ธ UNE EN ISO 1996-2 ๐Ÿ‡ณ๐Ÿ‡ฑ NEN EN ISO 1996-2
1,868 Accredited labs
20 Countries

Showing 151โ€“175 of 393 labs

UKAS 2719 Cannel Row, GB
(HSG 248) โ€“ 2021 TP003 based on HSG 248 (PCM) based on HSG 248 TP002 based on HSG 248 Appendix 5 of HSG 227 (2004) + 1 more
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UKAS 27551 Crook, GB
(HSG 264, 2012)
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UKAS 4238 Hereford, GB
Appendix 5 of HSG 227 (2004) (HSG 264, 2012)
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UKAS 2099 Exeter, GB
(HSG 248) โ€“ 2021 (PCM) based on HSG 248 SP1 based on HSG 248
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UKAS 9608 Basildon, GB
(HSG 264, 2012) and Appx. 3 of HSG 227 (2004)) Executive guides HSG 264 (2012)
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UKAS 2030 Chelmsford, GB
(HSG 248) โ€“ 2021 (PCM) based on HSG 248 staining based on HSG 248
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UKAS 28785 Wolverhampton, GB
(HSG 248) โ€“ 2021 SOP 3 based on HSG 248 (PCM) based on HSG 248
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UKAS 8007 Corringham, GB
(HSG 248) โ€“ 2021 (PCM) based on HSG 248 TP03 based on HSG 248
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UKAS 2734 Darlington, GB
(HSG 248) โ€“ 2021 TP005, based on HSG 248 (PCM) based on HSG 248
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UKAS 2183 Newmarket, GB
staining based on HSG 248. (PCM) based on HSG 248 (HSG 248) โ€“ 2021 DIN EN 12457-2 DIN EN 12457-3
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UKAS 0452 Bideford, GB
AC CURRENT AC VOLTAGE (continued) Measurement (continued) DC CURRENT Generation (continued) + 3 more
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UKAS 1574 York, GB
IEC 61000-6-1 IEC 61000-4-29: 2000 DIN EN 62233 IEC 61000-4-11: 2004 DIN EN 61000-4-12 + 3 more
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UKAS 2262 Ipswich, GB
ISO 6579-1 ISO 6888-1 ISO 16649-2 ISO 11290-1 1) AM/M/11-2 based on BS EN + 3 more
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UKAS 9659 Grimsby, GB
Method 15.2 based on BS EN ISO ISO 15213-2 Method 9.8 based on BS EN BS EN Method 5.11 based on BS EN ISO Method 4.3 based on BS EN ISO + 3 more
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UKAS 2622 Linlithgow Bridge, GB
ISO 6579-1 ISO 4832 EUMM 3.03 based on BS EN EUMM 3.07 based on BS EN ISO BS ISO 21528-2:2017 + 3 more
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UKAS 0342 Wolverhampton, GB
ISO 712 ISO 4833-1 on BS EN ISO 1736:2008 ISO 21528-2 BS ISO 4832:2006 + 3 more
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UKAS 9661 Teston, GB
(HSG 264, 2012)
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UKAS 0174 Stevenage, GB
BS 7177 BS 5852 DIN EN 597-1 BS 6807:1986 DIN EN 597-2 + 3 more
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UKAS 1780 Wickford, GB
M002based on HSG 248 (HSG 248) โ€“ 2021 (PCM) based on HSG 248
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UKAS 0166 Cannock, GB
(HSG 264, 2012) on BS 8580-1:2019 and ACoP L8
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UKAS 0183 Norwich, GB
Frequenc 220 mV range FREQUENCY 10 Hz to 100 kHz difference from 10 % to 100 % of the sta 6105A control 0ยฐ to 360ยฐ + 3 more
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UKAS 1497 Carrickfergus, GB
ISO Mark Casting (TS5527)
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UKAS 9875 Benfleet, GB
(HSG 248) โ€“ 2021 (PCM) based on HSG 248
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UKAS 2671 Castle Donington, GB
(HSG 248) โ€“ 2021 (PCM) based on HSG 248 DOC/002 based on HSG 248
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UKAS 4155 Sunderland, GB
5 of HSG 227 (2004) (HSG 264, 2012)
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Industries

Audio and sound system design Public address and emergency systems Telecommunications and broadcasting Educational and institutional facilities Aviation and maritime communication

Related Standards

  • ISO 3382-2 Acoustics - Measurement of room acoustic parameters - Part 2: Reverberation time in ordinary rooms
  • ISO 1996-2 Acoustics - Description, measurement and assessment of environmental noise - Part 2: Determination of sound pressure levels
  • EN 60268-1 Sound system equipment - Part 1: General

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