BS 7827:2019 Designing, specifying, maintaining and operating emergency sound systems for sports grounds, large public buildings, and venues. Code of Practice

Maintenance
Emergency measures
Safety devices
Reports
Crowd safety
Certification (approval)
Inspection
Audio systems
Forms (paper)
Speech transmission systems
Reliability
Instructions for use
Personnel
Sound intensity
Approval testing
Training
Audio equipment
Performance
Stadia
Warning devices
Electric power systems
Alarm systems
Signal distortion
Sports facilities
Safety measures
Public-address systems
Audibility
Acoustic measurement
Reception
Sound reproduction
Buildings
Control panels