Don't modify the original data-1.1.0.pk3. Instead create a new zip with same folder path/filename to the rant sound, but replace the file with an empty .wav file. The .pk3 should have a name alphabetically after data-1.1.0, like z-noroar.pk3. This will only work on unpure servers however, there is nothing you can do about pure servers unless you get the owners to put that same .pk3 on the server.