This standard provides guidelines for the acoustic design of auditoriums, conference halls, and cinemas to achieve optimal speech intelligibility and music clarity. It outlines recommendations for room volume, shape, reverberation time calculations, seating arrangements, and the strategic placement of acoustic treatments to mitigate defects like echoes and sound foci.
Code of practice for the acoustic design of auditoriums and conference halls
Quick Reference Values
Volume per seat for public address halls3.5 to 4.5 m³
Volume per seat for cinemas/theatres4.0 to 5.0 m³
Volume per seat for concert halls5.5 to 7.0 m³
Acceptable background noise for conference halls30 to 35 dB(A)
Typical Optimum Reverberation Time for speech1.0 to 1.5 seconds
Key Formulas
T = (0.16 * V) / A — Sabine's formula for Reverberation Time
Practical Notes
Avoid concave, cylindrical, or domed ceilings as they focus sound into hotspots; use diffusers or convex shapes instead.
Treat the rear wall facing the stage with highly absorptive materials to eliminate long delayed echoes.
Account for audience sound absorption during design, as the reverberation time changes significantly between an empty and fully occupied hall.