In rooms the inverse-square law applies only to the direct sound

Evidence

Academic discussions of sound propagation often begin with a “point source”. This is not the conventional forward-firing loudspeaker many people think of, but a theoretical sound source radiating equal energy in all directions and having no physical size. Sound from such a source is truly omnidirectional. If it radiates into free space, no reflections, the sound pressure decreases by 6 dB for each doubling of distance: this is the “inverse-square law”. In rooms this relationship therefore applies only to the direct sound. — Toole, Floyd E, Sound reproduction- the acoustics and…, 1260

Categorization

• DEFINE: Clarifies the point-source abstraction and precisely scopes when the inverse-square law holds.
• corroborated: 2 independent passages support this claim — Toole, Floyd E, Sound reproduction- the acoustics and…, 1260
• XREF: connects to: Inverse-square law governs direct sound intensity even inside enclosed spaces; Reflected sound obeys an inverse square law in addition to surface absorption losses; Speech comprehension depends on direct sound, which falls off with the inverse square law. (+2 more)

Broader Connections

• Inverse-square law governs direct sound intensity even inside enclosed spaces #corroborates (0.95)
• Reflected sound obeys an inverse square law in addition to surface absorption losses #contradicts (0.85)
• Direct sound intensity falls with the square of distance from the source #expands (0.82) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1691
• Speech comprehension depends on direct sound, which falls off with the inverse square law. #exemplifies (0.80)
• Statistical acoustics and classical critical distance do not apply in small rooms #qualifies (0.75) — Toole, Floyd E, Sound reproduction- the acoustics and…, 1312