A 3500 m³ lecture hall has the sound-decay curve shown. The source is switched off at P. Using RT 60, find total absorption in sabins, to nearest integer.
At P the level is 110 dB at 0.4 s. A 60 dB decay reaches 50 dB at 1.6 s, so RT 60=1.2 s. Sabine’s equation gives absorption A=0.161V/T=0.161×3500/1.2=469.583 sabins, rounding to 470. The full decay to the 30 dB background is 80 dB, not the RT 60 interval.
More Acoustics in buildings questions
GATE 2024 AR — Planning Q35– Match P floating floor, Q float valve, R metal float, S free float with 1 overflow…
