A defined frequency marks the transition between modal and diffuse acoustic behavior

Evidence

The transition boundary between the region of modal behavior and the region of diffuse behavior is known as the “critical frequency.” As is usual in these situations, although the critical frequency is a single frequency it is not a sharp boundary: it represents some defined point in a transition region between the two regions. — David Howard, Jamie Angus, coustics and Psychoacoustics, 2078

Categorization

• DEFINE: Definitions the reader needs — ‘critical frequency’ is a load-bearing concept for psychoacoustics of rooms.
• XREF: connects to: Modal behavior makes diffuse-field analysis fail in a mid frequency range — David Howard, Jamie Angus, coustics and Psychoacoustics, 2073; A transition frequency separates modal from ray acoustical behavior in rooms — Toole, Floyd E, Sound reproduction- the acoustics and…, 475; A single critical frequency marks the modal to diffuse transition — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2025 (+7 more)

Broader Connections

• A transition frequency separates modal from ray acoustical behavior in rooms #expands (0.95) — Toole, Floyd E, Sound reproduction- the acoustics and…, 475
• A single critical frequency marks the modal to diffuse transition #corroborates (0.92) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2025
• Room acoustical behavior changes across a broad transition region, not at one frequency #contradicts (0.88)
• Every room has a frequency below which modal effects break the diffuse-field assumption #expands (0.82) — David Howard, Jamie Angus, coustics and Psychoacoustics, 2066
• Modal behavior intensifies as wavelength approaches the room’s mean free path #expands (0.80) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2029
• Modal decay analysis governs room acoustics below the critical frequency #expands (0.78) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2038
• Modal bandwidths break diffuse-field assumptions when sound paths exceed the mean free path #qualifies (0.75) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2012
• Low absorption sustains strong modal variation in rooms at higher frequencies than predicted #complicates (0.75) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2033
• Modal density rising smoothly with frequency predicts perceptually smooth room response #complicates (0.72)