Room absorption determines the steady-state level of reverberant sound

Evidence

If a steady tone, such as an organ note, is played in the space then after a period of time the reverberant sound will reach a constant level because at that point the sound power input balances the power lost by absorption in the space. This means that the steady-state level will be higher in rooms that have a small amount of absorption, compared with rooms that have a lot of absorption. — David Howard, Jamie Angus, coustics and Psychoacoustics, 1781

A loudspeaker radiates a peak sound intensity of 102 dB at 1 m. What is the sound pressure level of the reverberant field if the surface area of the room is 75 m2 and the average absorption coefficient is (a) 0.9 and (b) 0.2? What would be the effect of doubling the surface area in the room while keeping the average absorption the same? — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1777

Categorization

• QUESTION: Worth working through numerically to internalize how much absorption changes perceived reverberance.
• corroborated: 4 independent passages support this claim — David Howard, Jamie Angus, coustics and Psychoacoustics, 1781; David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1777
• XREF: connects to: Occupied audiences absorb up to 90 percent of incident sound in a hall; Physical sound absorption can be strong enough to measurably alter room reverberation; Loudspeakers and rooms function together as a single audible system (+21 more)

Broader Connections

• Total surface area can outweigh absorption efficiency in controlling room reverberation #qualifies (0.85) — David Howard, Jamie Angus, coustics and Psychoacoustics, 1929
• Room sound energy decays exponentially through repeated surface absorptions #expands (0.82) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1830