Whenever I get an achievement on website, it makes a sword sound (Maybe just from Kingdom Rush Frontier game) which is very annoying since I am at work and always disable sounds of games, but don't see a way to disable website sounds or to disable the achievement from appearing on its own.
I think the only way right now to disable site sound is just put your computer speakers to mute. Quest sounds occur on every game the moment you reach the requirement for the Quest.
This isn't really an option, since many of our pre-roll ads within the games have sounds, and we don't have the option to have those play without sound. The only real way to disable sounds is to turn off sound on your computer.