-> http://hyperphysics.phy-astr.gsu.edu/hbase/Acoustic/revtim.html
Highlights
- $\text{RT}_{60}$: time to drop $60~\text{dB}$ below original level.
- For a general purpose auditorium for both speech and music: 1.5 to 2.5 seconds.
- Longer RT: richer musical sound, more difficulty understanding speech.
- Shorter RT: clearer speech, loss of richness and fullness.
- Reverberation time approximation: Sabine formula, $\text{RT}_{60} = 0.16 \frac{V}{S_e}$, $S_e$ is the effective absorbing area, $a$ is the absorption coefficient. $S_e=a_1S_1+a_2S_2+a_3S_3+\cdots$. -> http://hyperphysics.phy-astr.gsu.edu/hbase/Acoustic/revmod.html#c2
- Examples of reverberation times:
- Vienna, Musikvereinsaal: 2.05 seconds
- Boston, Symphony Hall: 1.8 seconds
- New York, Carnegie Hall: 1.7 seconds
