Room boundary reflections are the second loudest sounds a listener hears

Evidence

Measurements made in an anechoic chamber, or their signal-processed equivalents are the best descriptions of sounds that radiate from loudspeakers. Most loudspeaker listening is done in small rooms, with strong early reflections, so these data need to be processed and displayed in a manner that relates to what listeners hear. The fact that most rooms are at least somewhat rectangular, with vertical walls and horizontal floor and ceilings simplifies matters because those surfaces are responsible for the strongest early reflections—the second loudest sounds a listener hears. Measurements in anechoic chambers or the equivalent can yield masses of data, but not all of it is important to perceptions of sound and spatial qualities in rooms. Subjective measurements are the key to identifying those factors that influence our perceptions. In pursuing this rigid methodology, the hope was that it would lead to measurable performance targets, allowing engineers to design loudspeakers with confidence in how they would sound. — Toole, Floyd E, Sound reproduction- the acoustics and…, 55

Categorization

• DEFINE: Establishes why anechoic measurements alone are incomplete: the strongest early reflections from room surfaces rank second in loudness to the direct sound.
• corroborated: 2 independent passages support this claim — Toole, Floyd E, Sound reproduction- the acoustics and…, 55
• XREF: connects to: Near-wall listening positions create early strong rear reflections; Floor reflections are an inherent part of normal human listening — , Toole, Floyd E - Sound reproduction-…, 790; Room acoustics requires modeling direct sound then early reflections (+4 more)

Broader Connections

• Near-wall listening positions create early strong rear reflections #expands (0.85)
• Floor reflections are an inherent part of normal human listening #expands (0.85) — , Toole, Floyd E - Sound reproduction-…, 790
• Room boundaries alter loudspeaker output through reflected image sources #expands (0.85)
• Small playback rooms impose their own early reflections on recorded sound #expands (0.83)
• Room acoustics requires modeling direct sound then early reflections #expands (0.80)
• Reverberant fields supply most perceived loudness in normal rooms #complicates (0.80) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1776
• Wide-dispersion speakers plus room reflections create listener envelopment. #complicates (0.75)