Direct sound governs perceived quality in rooms, not room curves

Evidence

By itself, a steady-state room curve is incomplete data and it is a bold assertion (often repeated) that it is a definitive statement of sound quality as perceived by two ears and a brain (see Section 13.2.3). — , Toole, Floyd E - Sound reproduction-…, 1561 (#corroborates, via linked claim)

The first sound to arrive at the listening location, the direct sound, defines the localization of sound images, initiates the precedence effect that permits localization in reflective spaces, and provides an initial reference for comparison to later arriving sounds that, combined, result in perceptions of both spatial effects and sound quality. … From the very beginning of my subjective/objective examinations, listeners were unambiguously attracted to loudspeakers with flat and smooth anechoic on-axis (direct sound) performance. — , Toole, Floyd E - Sound reproduction-…, 1546 (#expands, via linked claim)

Categorization

• XREF: connects to: Reverberant rooms make loudspeaker directivity important for sound quality — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 474; Loudspeakers and rooms function together as a single audible system; Multichannel home theater benefits require delivering direct sound to all listeners in the room. (+10 more)

Broader Connections

• Room curves cannot define perceived sound quality on their own #corroborates (0.95) — , Toole, Floyd E - Sound reproduction-…, 1561
• Direct sound determines localization, loudness, and perceived spectrum quality #expands (0.90) — , Toole, Floyd E - Sound reproduction-…, 1546
• Non-environment rooms suppress all but direct sound for clearer audio detail and imaging #exemplifies (0.85)
• Perceived room quality depends on the energy-time curve, not just reverberation time alone. #qualifies (0.80)
• The gap between direct sound and reverberation encodes the perceived size of a space #expands (0.80) — David Howard, Jamie Angus, coustics and Psychoacoustics, 1776