Sorry to bump a year old thread but I thought that someone else may need help.
I have spent quite a while trying to find out what they are.
This is an excerpt of a guide I made for my own reference so it is written that way.
Police
Nautech siren used by the police cars. This siren is installed on vehicles which are nicknamed as the 'Nautech' vehicles. These vehicles are basically the marked sedan police cars. Uses a Code 3 C-Series speaker
Hazard 2000 series, and has the worst setup. When first turned on it sounds the Phaser for about 1 second before switching to the wail. It has a similar frequency range to the Able 2 Gen1 sirens, except a little faster and a couple of tones lower. Most of the time the police will keep it set to yelp, which is activated using the horn or on some new vehicles a rotary knob. This siren is also
signficantly quieter than other sirens. Speaker is a Hazard 810-002.
A
police bike has a very distinctive tone. The wail sounds like another kind of Chinese made siren, except it is using the square wave tones rather than the standard sine. This siren is made as part of a BMW police bike package, so I am not sure what they use on the Yamahas.
Fire
Signal Vehicle (Unknown model) has been used for a while, and siren tones have changed over that time. Speaker is a Federal Signal CP100 for the Mercs and a Dynamax or Whelen SA315 for the Scanias. Some (1 confirmed) also has a Federal Signal Rumbler.
Rural Fire uses a variety of sirens because of their age.
Ambulance
Newer Merc vehicles have a siren that sounds like its made in China.
Previous (Most common) have the 'trip' siren as I call it. Slowly comes up and then 'trips' over its peak and falls back down quickly. Still not 100% sure who made this but it could possibly be made by a NSW company called
Impart. I sent them an email and they said they did make them for QAS, aswell as for NSWFB, for which I have also found a vehicle with the same siren 'accent'.
Rapid response vehicles use the
Hazard 'Slic' 1000 Series.
I heard once that Code 3 siren amp was used at one stage although I have not heard one.
Older ambulances use a Hazard siren that also has a dual mode on some vehicles. This siren is still used in SA and is common in VIC.
Sites
Code 3/Britax
http://www.code3pse.com
http://www.britaxae.com.au/
Nautech
http://www.nautech.com/
Hazard Systems
http://hazard.com.au
Federal Signal
http://www.fedsig.com/
Signal Vehicle
http://star1889.com/
Impart
http://www.impartsp.com.au/
Whelen
http://www.whelen.com/home.php