This siren is primarily used by the Ambulance Service in Queensland, Australia. It contains a yelp and a wail.
Please, dear god, read the readme before installing this modification.
I will not provide support should your game break.
I'm aware that it sounds a little weird in parts, especially the apex of the wail, but there is not much that I can do to mitigate that. That issue was created when I amplified the siren so it could be heard in game.
Siren Showcase (ignore the skin on the vehicle)
Further updates may be made to the siren, but it is unlikely.