Just what is a silent subliminal message? Surely if you can’t hear a silent message it won’t work? Well yes and no. You see, silent subliminal is really a misnomer. Whilst it’s called silent, it isn’t really. It’s actually either a very high frequency message or a very low frequency one. Either way, it’s inaudible to humans. Which means it really ought to be called an inaudible subliminal. Except that wouldn’t sound as catchy. Silent subliminals have been around for some time. The patent application for them was filed way back in 1989. You can search it out if you’re technically inclined. Ok, so we’ve established what a silent subliminal is. Now, what do you do with them? Essentially, they’re a hidden communication. Providing that silent subliminals work, they can be added anywhere so long as the frequency range of the “carrier” medium is wide enough. Oh, and also if the “carrier” medium doesn’t use some kind of lossy compression. So your MP3 collection is almost certainly safe from silent subliminals. MP3′s get rid of information that we can’t hear in order to keep their file size down. On the other hand, your CD collection could be harboring silent subliminal messages if the artists you listen to are crafty enough to include them. Of course, systems like the Centerpointe Holosync CDs are up front about their use of silent subliminal messages. In fact, it’s part of their selling point. Rock bands could use silent subliminals. After all, they have been accused of other dodgy practices over the years, such as including backwards messages in their tracks. Whether or not that is true is a matter of conjecture. It could just have been dreamed up by the band’s publicity department in an effort to encourage rebellious teenagers to buy the music. Who knows?