pchesterI don't think you can turn off individual sounds, but (and I am speaking as a non-programmer person here) it might be possible to extract the sound file from the compressed game files and change it. The sound files are in .ogg format and are in (I think) gamedate.dbc, gamedate.dbd and gamedate.dbe. If you could then figure out which individual sound file it is (or if someone more technically minded than I am can tell you) you might be able to replace it with a different file using the same name.
There are a couple of extractor programs
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IMPORTANT: Only work on copies of the master files, and keep these and any extracted files away from your StalkerSoup game installation or you could mess up your game.
Do not try to re-insert your edited file back into the compressed file. When you have edited a file, copy it back into the relevant folder under STALKERSOUP\gamedata\ (you may need to create some sub-folders here) and test it. The game engine should use any files it finds under STALKERSOUP\gamedata\ in preference to the originals in the master gamedata.db* files.
If it doesn't work, just remove the new file and the game will revert to using the original in the db* file.