Home-room ‘reverberation time’ actually measures reflection or resonance decay

Evidence

The CEDIA/CTA—RP22 (2023) recommendation takes the step of calling it RdT, Reflection Decay Time. It is logical, but unnecessarily confusing because measuring instruments and algorithms will persist in calling it RT or RT60. This book will call it RT for simplicity, even though we know what it measures. But, if one is rigorous about names, RT measurements at low frequencies are probably measuring the ringing decay time of strong room resonances. A third name is needed. — Toole, Floyd E, Sound reproduction- the acoustics and…, 1233

Categorization

• QUESTION: What distinguishes Reflection Decay Time from resonance ringing decay measurement in practice - how would an instrument classify which it is reading?