Steady-state reverberant level is set by the balance between input power and absorption loss

Evidence

The steady-state level of the reverberant field: If a steady tone, such as an organ note, is played in the space, 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. Note that a transient sound in the space will not reach a steady-state level. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1742

Categorization

• DEFINE: Defines the ‘steady-state level’ concept precisely, including the key caveat that transients never reach it.
• XREF: connects to: The reverberant field is an integrated sum of intensities arriving from all directions — David Howard, Jamie Angus, coustics and Psychoacoustics, 1787