A single steady-state room curve cannot represent what two ears and a brain perceive.

Evidence

When a steady-state frequency response room curve is measured a curve results, but what does it mean? It is audacious to think that this one curve represents the complex timbral and spatial perception that two ears and a brain perceive from the combination of direct and reflected sounds. An evaluation 361. of sound quality might be the reason for the measurement, but listeners extract much more information from the combination of arriving sounds, spaciousness being a major factor—we hear “the room”, as well as the loudspeaker. In multiple-loudspeaker listening tests we know that listeners are able to perceptually separate the changing timbral characters of the loudspeakers from the fixed sound of the listening room. They recognize subtle performance attributes in the loudspeakers being evaluated although the room sounds are present in them all. But when there are no comparisons, as in a single-stimulus listening evaluation, such an analysis is not possible (Section 1.4). The same is true with a room curve. The measurement microphone simply adds the direct and all reflected sounds together and gives us the sum. Analysis is not possible, but analysis is necessary. — Toole, Floyd E, Sound reproduction- the acoustics and…, 1314

Categorization

• DEFINE: Explains why a steady-state room curve is a perceptual oversimplification — the microphone sums sounds that the ear/brain perceptually separates.
• SHARE: For anyone into hi-fi measurements: this is the core argument that a single frequency response curve can’t capture spaciousness or “hearing the room.”