Guide to Turn Off Narrator
Narrator Relevant Settings
Simple screenshot explains it all.
Under “Frequency” set Narrator to 0, will only remove his speeches outside of missions.
Under “Volume” set Speech to 0, mutes all speeches. (creatures talk gibberish, so those will not be affected by this setting.)
Subtitles under “General” are subtitles for narration outside of gibberish talks. you’d better have it turned on, as the narrator does have some informative information about certain missions from time to time.
It can happen, that even though, the Speech settings are off, the narrator will still talk. Make a new save and try if he still talks on a new save.
Known Fix: new save file.