Acoustics of Building

(1) Intensity Level

$$ L = 10 log_10(I/I_0) \text"(in dB)" $$
where, L is loudness

(2) Sabine’s Formula

$$ T = {0.165 V}/{aS} $$

where, T is Reverberation time
  V is Volume of hall
  S is Total area
  a is Absorption coefficient

Also, $ A = ∑↙{i=1}↖n aS $ where, A is Effective absorbing area