Hi all, I wonder if i could draw upon your wealth of knowledge, My local force is Greater Manchester Police- who use Premier Hazard equipment, so as a bit of nostalgia i have being trying to crate the perfect siren sounds for my vehicles in game. For those of you who dont know, Premier Hazard sirens (on some models at-least) have two tones, Whale and Yelp, the unique thing is that in the real vehicle, switching from Yelp back to Whale begins the siren half way through its cycle (example watch the below video and listen to the siren, you'l know what im on about https://www.youtube.com/watch?v=1aXQVJWpgKQ Now i have being trying to emulate this in GTA IV by editing the Police warning and Ambulance warning sounds in the Horns.ivaud file and using ELS to select which tone plays when. the replacement file Is attached and sounds fine outside of the game playing via media player or audacity - however when it is imported into the game, the sound wont play properly and sounds instead like a random clicking noise, is there a way to rectify this? The replacement file is the same length and frequency as the Siren_1 file (which i edited to make the replacement file) I have also tried using the same file in the both Ambulance_warning and Police_warning slots but to no avail Thanks AMBULANCE_WARNING.wav EDIT - Better video riding in a response van (more tone changes) https://www.youtube.com/watch?v=eNuF6twr3LE