All broadcasts, be they live announcements or continual music, can be sent to all areas of a site or to selected areas (referred to as zones). At all other times a voice alarm system is used to make public address announcements, broadcast advertisements or background music. It is a system that assists in the effective evacuation of an area or building during a fire, bomb alert or other emergency. A voice alarm system (sometimes referred to as a voice evacuation system) is installed with the safety of staff and general public in mind.