giant voice
n.— «Giant Voice System. This system is also known as Big Voice. The Giant Voice system is typically installed as a base-wide system to provide a siren signal and pre-recorded and live voice messages. It is most useful for providing mass notification for personnel in outdoor areas, expeditionary structures, and temporary buildings.» —“UFC 4-021-01: Design and O&M: Mass Notification Systems” Department of Defense (U.S.) Dec. 18, 2002. (source: Double-Tongued Dictionary)