in large buildings, a central fire alarm annunciator panel is located where it is accessible to fire-fighting crews. the annunciator panel will indicate the zone and approximate physical location of the source of a fire alarm in the building. the annunciator will also include lamps and audible warning devices to indicate failures of alarm circuits. in a large building such as an office tower or hotel, the fire annunciator may also be associated with a control panel for building ventilation systems, and may also include emergency communication systems for the building.