It was alleged by opponents to rock and heavy metal that the artists would include hidden satanic messages in their songs that would become audible when playing the song backwards.
It was further claimed that the brain would still be able to subconsciously decode the message and thus manipulate the person in a subliminal way.
I know that the pattern-seeking behavior of our brain will make us hear things that are not there, such as whispering voices in the wind, or voices in white noise. Thus, a plausible explanation of the backwards messages is that the brain makes these things up when listening to something that sounds like spoken words, as spoken words backwards clearly are.
This is, however, still not prove that nobody deliberately put backwards messages into music. Thus my question:
Is there conclusive evidence that subliminal messages (i.e. reversing audio) has been attempted in rock or heavy metal music?