Backmasking - Use

Use

Backmasking has been used as a recording technique since the 1960s. In the era of magnetic tape sound recording, backmasking required that the source reel-to-reel tape actually be played backwards, which was achieved by first being wound onto the original takeup reel, then reversing the reels so as to use that reel as the source (this would reverse the stereo channels as well). Digital audio recording has greatly simplified the process.

Backmasked words are unintelligible noise when played forward, but when played backwards are clear speech. Listening to backmasked audio with most turntables requires disengaging the drive and rotating the album by hand in reverse (though some can play records backwards). With magnetic tape, the tape must be reversed and spliced back in to the cassette. Compact discs were difficult to reverse when first introduced, but digital audio editors, which were first introduced in the late 1980s and became popular during the next decade, allow easy reversal of audio from digital sources.