I had this problem and eventually was told (correctly) that it was an error/problem with dreamscapes.
Every 5 seconds and voice came over saying "This has been and aero expierence and win monkey production" and the sound looped over and over again, even after a hard restart. I was terrified that I'd been infected with a vius. 
I was NOT.
The solution was to to simply change my current dreamscape and the loop ended nicely and has yet to return.
