Akmenrah is the fictional pharaoh from Night at the Museum, but other than that I can't tell you much. Your name, coupled with this, tells me you like Egyptian mythology. It could be a mantra, or some sort of message from a guide. You could try meditating on it and see what you get :)
Also, hearing it that much you may want to get it checked out, just to be safe. Hearing voices is one thing, but to have them going at you persistently for 24 hours may mean the onset of something serious :/ How long has this been going on for?