User blog comment:Inferno Pendragon/World Building 1 : Tech Levels/@comment-1070010-20160302153146/@comment-1705775-20160302160745

actually, it is established that language was created after the Eodian War by the Powers That Be to try and ensure peace.. thus language in our multiverse was a cosmic invention rather than a natural process, thus a device that homes in on whatever cosmic "stuff" the Powers That Be used would theoretically work.. basically many species could create a very primitive version of the Tower of Babel (which is established as the supreme technology in regards of altering any and all language).

Maybe Earth's translator was gifted by an alien race or alternatively ISDF (or an earlier incarnation) reverse-engineered stolen alien technology.. if all else fails we can have it linked to knowledge passed down in the Hyborian Era by the old ones, elder-gods, outer gods or Watchers..