The ITU-R BS.1116 standard is routinely misapplied to loudspeaker evaluation rooms.

Evidence

Figure 12.1(c) shows target ranges for RT from some international recommendations. The IEC 60268-13 (1998) document is intended to provide guidance for conducting listening tests on loudspeakers, and presumably for enjoying them. ITU-R BS.1116–3 is aimed at a very different audience. The introduction states: “This Recommendation is intended for use in the assessment of systems which introduce impairments so small as to be undetectable without rigorous control of the experimental conditions and appropriate statistical analysis.” In other words, this is not what is needed for evaluating loudspeakers, or for being entertained by them. Nevertheless, the document often appears as one of the performance requirements for rooms used for general audio evaluations. EBU Tech 3276–2nd edition (1998) and EBU Tech 3276-E (2004) address the very different needs of broadcasters needing standardization of their listening circumstances. The loudspeaker and listening room requirements are identical to the ITU document. — Toole, Floyd E, Sound reproduction- the acoustics and…, 1237

Categorization

• QUESTION: Worth chasing: exactly how do ITU and IEC RT targets differ numerically, and what listening impairments does each guard against?
• SEED: Could be an essay angle: how an audio-industry standard written for detecting tiny codec impairments gets cargo-culted into home theater design specs.