This Standard specifies the characteristics of acoustic signals to be used for audible emergency evacuation and audible evacuation signals with relocation instructions. It applies to the audible signal only and not to the signaling system components or equipment. The audible emergency signal is intended to draw the attention of all persons within the signal reception area to an emergency situation (fire, gas leaks, explosion, nuclear radiation, etc.) requiring immediate evacuation from the area. This Standard specifies parameters of the audible emergency signal, i.e., the temporal pattern, the required sound pressure level at all places within the intended signal reception area and the spectral content for certain applications, in order for the audible emergency signal to be recognizable.