Room modes produce multiple decay times instead of a single exponential reverberation

Evidence

The decay of sound energy in the room is no longer a single exponential decay with a time constant proportional to the average absorption in the room. Instead, there are several decay times. The shortest one tends to be due to the diffuse sound field, whereas the longer ones tend to be due to the resonant modes in the room. This results in excess energy at those frequencies with the attendant degradation of the sound in the room. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1996

Categorization

• DEFINE: Clarifies how modal resonances create multiple decay times, a core psycho-acoustic concept for the reader’s stated purpose.
• corroborated: 2 independent passages support this claim — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1996
• XREF: connects to: Room sound homogeneous decay holds for typical rooms but can be engineered away; Sabine experimentally verified exponential sound decay in a reverberant room; Identical reverberation times can mask drastically different room sizes and acoustics (+12 more)

Broader Connections

• Room modal bandwidths depend on decay time, not frequency #expands (0.85) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2012
• Modal decay analysis governs room acoustics below the critical frequency #corroborates (0.85) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2038
• Reverberation time is defined as a 60-decibel energy decay #qualifies (0.80) — Schafer, Murray R, The Soundscape- Our Sonic Environment…, 446
• Room reverberation time varies with frequency, altering perceived timbre #complicates (0.75) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1876