Moved my initial post to this topic since I figured it’s more appropriate here.
Unfortunately game_sounds_player.txt doesn’t have a sound entry for when the player gets hit by bullets or getting bitch slapped with a gun, wanted to add the player hurt sounds whenever you get hit in the campaign. Half Life 2 didn’t have this either though so I’m not sure how this could be done. Haven’t dealt with the Hammer editor before, only tweaks I’ve ever done were editing the script files, amongst other things.
I’ve found this post from a blog that seems to have what I’m looking for but have no idea where the player.cpp file is.