NOTE – The Eyring reverberation-time equation is:

${\displaystyle T=\frac{\left(24\text{ln}10\right)V}{-cS\text{ln}\left(1-\overline{\alpha }\right)}}$

where:
T is the reverberation time
V is the volume of the room
c is the speed of sound in the contained air
S = Σ S_i is the total area of surfaces of the room
$\overline{\alpha }=\text{Σ}{S}_i{\alpha }_i/S$ is the area-weighted mean Eyring coefficient of all the surfaces
S_i is the area of the i-th surface
α_i is Eyring sound power absorption coefficient attributed to the i-th surface. The equivalent absorption area of the i-th surface is S_iα_i.