Decades back, when "backwards masking" was "discovered" in Stairway to Heaven, when only by ruining our phonograph needles could we find out how Paul McCartney died (hint: in a car crash), my brother and I did some recordings where we'd sing something forwards, play it backwards, learn the whole backwards version phonetically, record it that way, and play it back. The weird thing was, often, the words sounded fine, the voices were just a little bit off on the attack/decay ends. Kind of a bust of an experiment, but fun, especially the bizarre constructions we wrote down as the backwards "words."

I absolutely do not buy into backmasks. It's all aural pareidolia. But, while looking for O saying "Yes we can," I ran across this video, and so I pass it along, but just for fun.
http://youtu.be/jqALdkTArqs