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
🇩🇪 DIN EN ISO 3382-2 🇬🇧 BS EN ISO 3382-2 🇫🇷 NF EN ISO 3382-2 🇮🇹 UNI EN ISO 3382-2 🇪🇸 UNE EN ISO 3382-2 🇳🇱 NEN EN ISO 3382-2 🇩🇪 DIN EN ISO 1996-2 🇬🇧 BS EN ISO 1996-2 🇫🇷 NF EN ISO 1996-2 🇮🇹 UNI EN ISO 1996-2 🇪🇸 UNE EN ISO 1996-2 🇳🇱 NEN EN ISO 1996-2
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SysKal

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Hexagon Metrology Raumdiagonale von GmbH, Wetzlar, D ≤ 1500 mm Polyworks, Software von InnovMetric, Lindau, D PowerINSPECT, Software + 3 more
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ISO 5-3 ISO 12647-1 ISO 13655
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ISO 3074 DIN EN ISO 1833-4 DIN EN ISO 1833-5 DIN EN ISO 1833-6 DIN EN ISO 1833-7 + 3 more
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DAkkS D-PL-21117-01-00 Bremen, DE
DIN EN 61400-11 IEC 61400-11, Edition 2.1 DIN 45645-1 DIN 45680 Bbl. 1
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DIN ISO 11466 UNE-EN 12880 ÖNORM EN 12457-4 ISO 10523 DIN EN 27888 + 3 more
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DAkkS D-K-17684-01-00 Schalkau, DE
Kraft (WPM) Kraftmesseinrichtungen von Werkstoffprüfmaschinen Acoustics — tonality assessment (DIN 456 Länge (WPM) + 3 more
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DAkkS D-PL-11197-01-01 Bremen, DE
DIN EN IEC 60068-2-13 DIN EN IEC 60068-2-52 DIN EN 60068-2-64 DIN EN 60068-2-78 DIN 53505 + 3 more
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DAkkS D-K-11048-01-02 Darmstadt, DE
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Taupunkttemperatur Railway braking — urban guided transport Widerstandssensor –40 °C bis > 5 °C bis + 3 more
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DAkkS D-K-18666-01-02 Germering, DE
Absolutdruck p 0,015 bar abs > 1,7 bar > 70 bar > 100 bar + 3 more
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DAkkS D-K-19475-01-00 Solingen, DE
Kraftaufnehmer und Kraft (WPM) * Vibration measuring instruments — test m maschinen nach DIN Acoustics — tonality assessment (DIN 456 + 3 more
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DAkkS D-K-18316-01-00 Backnang, DE
Gleichspannung 0 mV Messgeräte 10 mV Wechselspannung 0,22 mV > 220 mV > 2,2 V + 3 more
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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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