Warning systems are designed to alert and evacuate building occupants in the event of an emergency. A building evacuation is typically conducted in accordance with a defined set of emergency response procedures.Loudspeakers or sounders are located throughout the premises.
There are two standard signals Alert and Evacuate which are either a tone or a tone with a voice message. These messages may also be configured to assist occupants in multi-lingual environments.
For all warning systems visual alarm devices (flashing lights) may be installed in areas where there are high ambient noise levels which would make audible alarms ineffective. Visual alarms are required in hearing impaired occupant designated areas.
Warning systems with loudspeakers may also be used for non-emergency purposes such as public address, or background music. The system automatically overrides these features in an emergency condition.