Update 4-26-18
Will update combat sounds as soon as the listfile for CASC is current, right now I can't pull up the newest sound files to change them. Probably see results during the next expansion in August. If you have a updated listfile for CASC that includes the 7.3 patch info, let me know as the one that's out now isn't updated to that version, but I probably did it wrong since I'm still new at this.
I edited some of the combat sound files to not be as loud as they are in game to below half of what they sound like. Currently this is updated to 7.2.5 and unlikely to update after since it was a huge pain. We'll see.
This does NOT mute sounds, if you want muted sounds go to:
https://mods.curse.com/addons/wow/mute-wow-sounds
http://www.wowinterface.com/downloads/info21893-finalversion.html
Both which mute most of those sounds in-game, however they do not seem to be updated to current versions of the game. If I missed any, please let me know and I'll do my best to update it. Probably.
HOW TO INSTALL:
Go to your World of Warcraft folder and place them into the "Spells" folder.
Add the files to look like below.
\World of Warcraft\Sound\Spells
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