If you record yourself saying, "I now are am" and then play it backwards it says Marijuana quite clearly. We used to always use cassette tapes and then open em up and flip flop the reels inside. I remember a whole tape I made from NIN Downward Spiral. I had heard he was using backwards bees humming, but theres some interesting things in there. I am more interested in what is intended that what is just people with a cure looking for a disease.
"If human speech is recorded and played backwards, mixed amongst the gibberish at regular intervals can be heard very clear statements. These statements usually appear in short sentence form and are nearly always related to the forward speech. It appears constantly throughout language, so much so in fact, that it is believed to be a natural part of our speech processes."