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Articles tagged “iec 60268-16

9 articles covering iec 60268-16 in acoustic engineering and building design.

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STANDARDS13 min read

IEC 60268-16: Measuring Speech Intelligibility (STI/STIPA)

A practical guide to IEC 60268-16 speech intelligibility measurement — STI and STIPA methods explained, equipment requirements, field measurement procedures, and common interpretation errors.

March 20, 2026
IEC 60268-16STI
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GUIDES8 min read

Speech Transmission Index (STI): What It Is and Why Your Building Might Fail

Learn how Speech Transmission Index (STI) is calculated per IEC 60268-16, why buildings fail speech intelligibility tests, and how to fix poor STI scores.

March 20, 2026
STIspeech intelligibility
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TUTORIALS6 min read

How is STI Measured?

STI (Speech Transmission Index) is measured using modulation transfer functions derived from impulse responses or STIPA test signals. Learn the full-band and STIPA methods per IEC 60268-16.

March 20, 2026
STISTIPA
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TUTORIALS5 min read

What is Speech Intelligibility? The Science of Being Understood

Speech intelligibility measures how well listeners understand spoken words in a space. Learn about STI, STIPA, the factors that affect it, and the standards that define acceptable levels.

March 20, 2026
speech intelligibilitySTI
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TUTORIALS11 min read

How to Calculate STI for a Classroom — IEC 60268-16 Step-by-Step

Full STI calculation for a 200 m³ classroom. Derive RT60 via Sabine, then compute speech transmission index using the modulation transfer function method per IEC 60268-16:2020.

March 18, 2026
STI calculationclassroom
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GUIDES13 min read

STI Measurement — The Speech Metric 90% of Architects Ignore | AcousPlan

Speech Transmission Index below 0.60 means poor intelligibility. IEC 60268-16 step-by-step calculation with classroom worked example. Free STI estimator.

March 18, 2026
STIspeech transmission index
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PILLAR14 min readFeatured

Speech Transmission Index (STI) — The Complete Technical Reference

The definitive technical reference for STI (Speech Transmission Index) covering MTF theory, the full 98-point calculation method per IEC 60268-16:2020, STIPA and RASTI simplified methods, the CIS intelligibility scale, measurement equipment and methodology, STI targets by room type, and the relationship between RT60, background noise, and speech intelligibility.

March 14, 2026
STI complete guidespeech transmission index
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TUTORIALS19 min read

What Is STI (Speech Transmission Index) — Can People Actually Understand Speech in Your Room?

STI measures how much a room degrades speech from source to listener, on a scale from 0 (unintelligible) to 1 (perfect). An STI below 0.50 means one in four words is lost. Here is how STI works, what scores you need, and why reverberation time alone is not enough.

March 14, 2026
STIspeech transmission index
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STANDARDS20 min read

IEC 60268-16 Complete Guide: Speech Transmission Index (STI) Standard

IEC 60268-16:2020 defines the Speech Transmission Index — the definitive metric for speech intelligibility in rooms. Here is every aspect of the standard explained: the STI calculation method, STIPA measurement procedure, quality scale, and how building codes worldwide use it.

March 14, 2026
IEC 60268-16STI