Did you maybe mean backpacking?
- back + masking (Wiktionary)
“April 4th, 2007 at 9: 31 pm its not an actual sumbliminal message as in a line or speech thats played in reverse as u guys that are saying "just sounds like jibberish" … its called backmasking … someone recording them talking or singing or rapping, and then adding it to the song backwards in a lower volume so its not heard wen played forwards … i should kno … ive done it a couple times in my music to jus to see wat it sounded like … and now for my opinion on the video … its totally fake … DJ Dangermouse chopped n screwed it from a couple of different verses from Jay-Z's songs … he even openly admitted it that Jay-Z had nothing to do with the backmasking of that time …”
“Hey, I hope most of you do realize that many of the so called backmasking is really what is called a phonetical reversal.”
“But beyond unforgettable songs and legendary live shows, Led Zeppelin broadcast a powerful message to fans who were tuned in to their music at a particular frequency -- one far more subversive than the Satanic messages the band was accused of "backmasking" into "Stairway to Heaven": Bring the soul of the West and Islam together, it told us, and you can produce a musical force powerful enough to break through the barricade dividing the two civilizations.”
“J12: Katie Couric interviews Sarah Palin. transcript, played backwards to reveal demonic backmasking jeff vandermeer says:”
“But what he's REALLY doing is backmasking Britney Spears records. . .”
“His devil character in this one is creepy as hell, and his voice sounds like the backmasking from your favorite Ozzy and Judas Priest records.”
“HUCKABEE: So, the next thing you will know, somebody will be playing it backwards to find out the subliminal messages that are really there in backmasking.”
“This, of course, is backmasking--a message "hidden" in an audio recording that is only apparent when played backwards.”
“Jeff Milner's handy-dandy backmasking site lets you play songs forwards or backwards, and it even displays the secret satanic messages for you while you listen.”
“The problem with backmasking is that there are so many demonic dialects, who can possibly keep up?”
Looking for tweets for backmasking.