Shut is a very simple mod, it allows modpacks to be shipped with configs that set sound levels, by default it turns music off but sets all other to 100%
To config the mod go to config/Shut/config.acfg the default looks like this
music=0
neutral=1
records=1
players=1
voice=1
ambient=1
hostile=1
weather=1
master=1
blocks=1
doReload=false
You can modify it as you see fit.
the settings should only be changed by the mod on the first boot, if you wish to use the config file to change them after, set doReload=true and it will update that next time you hit the title screen