Question

A hall has a volume of 2000 m³. Its total absorption is equivalent to 90 m² of open window. What will be the effect on the reverberation time if an audience fills the hall and thereby increases the absorption by another 90 m²? 

Answer 1

When the hall is filled with the audience, the total absorption a′ becomes 90 + 90 = 180 m² of open window. The new reverberation time T ′ is