salazar420

So, when you extract the sound files from the vehicles.awc file using OpenIV, it creates a bunch of .wav files (known sound format, that way we can edit them, .awc is just an archive of sounds) and these files are internally labeled by the game with different names such as POLICE_WARNING for the priority siren or AIRHORN_EQD for the air horn, though because .awc is a archive format proprietary to Rockstar Games, the developers of OpenIV had to come up with their own algorithm to extract it, and so they didn't have access to the internal labels for the files, but only to the corresponding hexadecimal labels. Now they've managed to find out more of these internal labels and thus the files that you extract from the vehicles.awc won't be labeled with their hexadecimal number anymore, but with the actual name used internally by the game. Or at least this is the explanation I came up with using my computer knowledge 🙂
All of this to say, sirens that you download are still labeled using the hex numbers, so you have to rename them to whatever their internal label is, for example the main wail siren that used to be 0x0D329446.wav, is now SIREN_PA20A_WAIL.wav. Hope it makes more sense.
 
EDIT: I figured you were probably more interested in a more clear explanation on how to install the sirens lol
Just take the custom siren you want to install, it should have 4 or 5 files three of which are named SIREN_2.wav, AMBULANCE_WARNING.wav and POLICE_WARNING.wav. The others are most likely 0x0D329446.wav and 0x0EA58C7C.wav. Due to the reasons I explained above, you now have to rename these two respectively to SIREN_PA20A_WAIL.wav and AIRHORN_EQD.wav before copying them into the vehicles folder after you extracted the vehicles.awc file using OpenIV.