- Distinctly Audible
The term distinctly audible was first used in the fire protection industry in Australia as part of Australian Standard AS1851:2012 to provide an objective method to determine if a loudspeaker was loud enough (> 65
dB: What is a decibel? - University of New South Wales, School of Physics, https://www.animations.physics.unsw.edu.au/jw/dB.htm at 1m) when tested to provide adequate warning to the occupants of a building in the event of the operation of an occupant warning system or emergency warning system in an emergency.