This Standard recommends design criteria for conditions affecting the acoustic environment within occupied spaces. The ambient sound levels recommended take into account the function of the area(s) and apply to the sound level measured within the space unoccupied but ready for occupancy (see Note 1). The Standard is applicable to steady-state or quasisteady- state sounds. The reverberation times recommended are for the occupied state of the enclosure.

This Standard also specifies methods of measuring the ambient sound level and reverberation time in occupied spaces in new and existing buildings.

NOTES:

1. The sound level during occupancy will usually be increased owing to the activities of the occupants.

2. Reverberation times for selected spaces (music studios, cabarets and theatre restaurants, and spaces for speech) are given in Appendix A. See also Clause 5.3.

3. Specialist acoustic advice should be sought for auditoriums or studios.