V10Siren soundpack #1 by Gordon Dry:
https://mega.co.nz/#!GN5FWJKL!BrMh9rPbRARs7uVD9rnT08gcCvONmi2sNuO8xutO_s8

V10Siren soundpack #1a (-12 dB) by Gordon Dry:
https://mega.co.nz/#!SYZEWYyY!eeU1qHYju7HMRV2i3tCtTaF8zFZvO0sIZO4ajiaJdz4

V10Siren soundpack #2 (-12 dB) by Gordon Dry:
https://mega.co.nz/#!3EwXDLaA!cBqehhFS43lCmxcbuouIRqtNaDiTZakmnTKAW0VeChA

Attention! 5:49 long - only the V10Siren.ogg for Police and Ambulance, if you want it also for Fire Trucks, create a copy of the V10Siren.ogg, rename it to V10FireSiren.ogg and copy it back in.
The sound is stolen from the popular youtube video https://www.youtube.com/watch?v=Ldi-6Lbr7hM and cut a little to be loopable.

I just decided to add the pack #2 as a normalized variant (louder).
I also included both files, more file size but less fiddling to do.

V10Siren soundpack #2a (max dB) by Gordon Dry:
https://mega.co.nz/#!uIQiEACD!uzn1YQ6dTAEUbutOWpJRwZcjrZzUqhr0dL0XgzFSVtw

Dutch Siren Pack: http://cloud.directupload.net/12wp

This another sound pack for V10lator's great V10Sirens June 7th update.

(USA Emergency vehicles)

Ambulance Siren is roughly the same but toned down a bit and with a few yelps and welps added
Police Siren is the Ambulance siren on steroids... yelp, welps, rumbler
Fire Siren is all the above with horns.

All sounds are from sound tracks appropriate to their vehicles. They are not overbearingly loud. I've toned down the Ambulance quite a bit.

I've included a ZIP file with all three files and separate files to download individually.

http://1drv.ms/1AUKH1B

Here's a US Sound pack with Whelen Wail & Yelp for Ambulance and Police and a Mech Siren for Fire Engines. Sounds loop well and are of good quality (no background noise) with a light echo effect, and volumes are on an equal level.

US Whelen & Mech sirens V1[1drv.ms]

UK Sirens - W.I.P.

Police Siren[www.dropbox.com]

Deutsche Martinshörner (Polizei, Feuerwehr, Rettung).
German Sirens: Police, Firefighters, Ambulance

Deutsche Martinshörner[www.dropbox.com]

Österreichische Martinshörner. (Polizei, Feuerwehr, Rettung).
RTW und Feuerwehr wie in Dt.. Polizei wurde angepasst.
Austrian Sirens: Police, Firefighters, Ambulance
Österreichische Martinshörner[www.dropbox.com]