A voice alarm (VA) or evacuation (EVAC) system is a means of alerting people to an emergency in a clear and unambiguous manner with the minimum of delay.
A public address voice alarm (PAVA) system is installed in a building to provide both clear and concise day to day messages, as well as specific alerts and messages in the event of an emergency.
Research has shown that voice alarm messages result in quicker reaction times than when sirens or bells are used, and live announcements were found to result in faster recognition times than recorded announcements. This has resulted in Voice Alarm or VA and PAVA becoming frequently commonplace as the primary means of evacuation in public buildings.