Many venues with large numbers of people or multiple floors, (eg. sports venues, theatres, leisure attractions and shopping centres), are advised to have a PA/VA or Voice Alarm System. The main differences from a standard public address system are that;
- it includes stored messages triggered manually or via the fire panel instructing the public on what action to take, (eg. standby for further instruction or evacuate).
- it has battery backup allowing the system to function long enough for evacuation.
- the condition of all parts of the system are continually monitored electronically, (eg. speaker lines, amplifiers, messages, microphones and back up batteries).
The installation needs to comply with British Standard BS5839 Part8 and more recently European Standard EN-54. This requires a very high level of design and specification which inevitably results in a higher overall cost.