Ok,There is a mod for beamng for sounds but don't you think that it will be great if horns or siren sounds were added to the game anyone Update: Just added in new Update
i saw a mod with added alarms It's somewhere in the forums, i found it like 3 weeks ago, have not seen it since.
there's a mod that adds sirens and horns and a few other sounds https://beamng.com/threads/siren-horn-mod-and-more-3-6-2-work-with-0-10-0-1.38669/