The Siren Board

i had always thought to confirm that whelens produce a square or rectangular wave, but when i looked further at a manual, it shows something of a triangular wave?
What the manual says:

Tone symbol Freq.

Alert /------\ 560Hz
attack ^^^^^^^ 410-490Hz
Whoop ///////////// 300-465Hz

these are the tones that made me wonder

Those are just the illustrations of the siren pitch through the signal.

Has nothing to do with the shape of the soundwave.