Articles tagged “speech transmission index”
4 articles covering speech transmission index in acoustic engineering and building design.
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.
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.
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.
The School Nobody Could Learn In: What ANSI S12.60 Failures Cost Students
35% of UK classrooms fail BS 8233 acoustic targets. The reason is not RT60 — it is STI. Architects design for reverberation time and ignore the speech transmission index calculation that ANSI S12.60 and DIN 18041 actually require. This is what that costs.