I've been getting PM's on how I did this and thought I would post some instructions. It looks daunting on the surface but is actually very easy to do and just takes about 3 - 5 minutes to complete. You just need to open some files with notepad and do some editing. For those who can't wait until I upload the fire truck - Here we go:
This is for adding unusual sounds (such as a siren) to drivable vehicles and/or ships. I used Ndicki's ship horn "read me" as a template and made some minor modifications to suit my needs. I just followed the path that he had already laid down.
1. Pick a .wav file of your choice or create one and give it a name, be sure that it starts with "ai_". In this case I used a .wav file from outside of CFS3 and named it "ai_vehiclesiren" and will use this as a reference in the following example.
2. Paste YOUR .wav file into the main CFS3 sound folder.
3. Find the sounds.xml in the main CFS3 folder and open it with notepad. Paste the following lines into the sound.xml between the lines </ac_damage> and <impact Looping="No" Static="Yes" Random="Yes" InternalOnly="no" Class="Damage">:
<vehicle_siren Looping="Yes" Random="Yes" Static="yes" Class="Engine" No3d="Yes">
<fire_truck>
<sound file="ai_vehiclesiren.wav"/>
</fire_truck>
</vehicle_siren>
Close the sounds.xml and save.
"Vehicle_siren" and "fire_truck" are just terms I used. You may try "emergency_alarm" and "fire_brigade" or whatever trips your trigger.
4. Find the effects.xml in the main CFS3 folder and open it with notepad. Paste the following lines near the top of the effects.xml immediately under the line <effects>:
<snd_vehiclesiren ClassName="SoundEffect" Sound="vehicle_siren/fire_truck" InitialDelay="0.0" MinDistance="1" MaxDistance="1000" Volume="100" Loop="1"/>
<fx_vehiclesiren ClassName="GroupEffect" Effect0="snd_vehiclesiren"/>
Close the effects.xml and save.
Again, "vehiclesiren" is just something I used like "vehicle_siren" and "fire_truck". If you change those names to something else, make sure the change is reflected to those lines in step 3 and vice/versa.
5. Find the ship or vehicle that you wish to add the sound to and open it's .xdp file with notepad (example: p_47d.xdp). Scroll all the way down to the bottom of the .xdp until you reach the effects section. Paste the following line into the effects section:
<Effect Type="StartEngine0" EffectName="fx_vehiclesiren" MinVel="0.01" MaxVel="150"/>
It will now look something like this:
<Effects>
<Effect Type="StartEngine0" EffectName="fx_vehiclesiren" MinVel="0.01" MaxVel="150"/>
<Effect Type="StartEngine0" EffectName="vehicle_headlight_red" PosX="0.0" PosY="1.0" PosZ="1.33" MinVel="0.01" MaxVel="150"/>
<Effect Type="StartEngine0" EffectName="vehicle_headlight" PosX="-0.9" PosY="-0.2" PosZ="2.9" MinVel="0.01" MaxVel="150"/>
<Effect Type="StartEngine0" EffectName="vehicle_headlight" PosX="0.9" PosY="-0.2" PosZ="2.9" MinVel="0.01" MaxVel="150"/>
<Effect Type="StartEngine0" EffectName="vehicle_headlight_ground" PosX="0.0" PosY="-1.5" PosZ="7.0" MinVel="0.01" MaxVel="150"/>
<Effect Type="StartEngine0" EffectName="fx_ac_Light_nav_red" PosX="0.58" PosY="-0.68" PosZ="-3.0" MinVel="0.01" MaxVel="150"/>
<Effect Type="StartEngine0" EffectName="fx_ac_Light_nav_red" PosX="-0.58" PosY="-0.68" PosZ="-3.0" MinVel="0.01" MaxVel="150"/>
<Effect Type="StartEngine0" EffectName="fx_engstrt" Location="emitter_eng0_exh_r"/>
<Effect Type="StartEngine0" EffectName="fx_engstrt" Location="emitter_eng0_exh_l"/>
<Effect Type="StartEngine0" EffectName="fx_smoke_touchdown" Location="emitter_eng0_exh_r"/>
<Effect Type="StartEngine0" EffectName="fx_smoke_touchdown" Location="emitter_eng0_exh_l"/>
</Effects>
Close the .xdp and save.
6. Start CFS3 and "fly" the ship/vehicle you just modified. When you start the engine on the runway you should hear the .wav file that you just installed.
I'm currently adding this effect to the stock a_firetruck (the one you see from the air driving around airfields) and will post info on how to modify that shortly.
