Public Address System in buildings are used for important message broadcast and the evacuation of people in emergency situations.

While message broadcasting aims to convey important messages for people, voice evacuation's goal is to evacuate them to a safe environment.

The size and the acoustic structure of the area, the number of zones and special requests determine the system's structure. It is possible to establish different sized systems, from a single zone to hundreds of zones, from a single announcement point to hundreds of announcement points.