The Giant Voice system is used to provide situational awareness of Station issues to its personnel during exercises and real time emergency events around RAF Croughton and around the MoD part of the village.
Further, the system provides a facility to broadcast the UK and US National Anthems during daily Retreat ceremonies (lowering of the US and UK flags). Retreat ceremonies are only broadcast at Royal Air Force Croughton and performed on weekdays, except UK and US holidays, at 1600 hours and 1700 hours during Daylight Saving periods. The proposed operation of the Tannoy System at Caversfield is that noise output at the point of origin will be no more than 60 decibels in all directions.
Tests will be carried out at a level of 60 decibels once per month. Testing consists of a 20-30 second solid tone followed by a voice announcement stating that it is only a test of the system. Clearly, should the system be needed for real in the event of an emergency then it will broadcast. Testing of the system is essential to its effectiveness. Previously the Base used a silent test feature to ascertain system status without actual sounding of the siren. When the system was called on to do its job after the London bombings of 7 July 2005, the system failed to operate in most locations even though the silent tests showed the system operational. To prevent this from happening with the new system, a monthly sounding schedule was devised and co-ordinated with the local council in December 2006.
The speakers are designed to project 60 decibels at optimal conditions; however poor weather and low wattage can reduce this to 50 decibels. These tests are performed on the first Thursday of each month and consist of a 20-30 second solid tone followed by a voice announcement stating that this is only a test of the system. Scheduled broadcasts (e.g. tests and exercises) are notified to neighbouring residents, Parish Councils and District Councils. The dates of testing will be published in due course.