How to Create Ultrasonic Subliminals?

Sorry if this is the wrong section. I’m Running Ubuntu 16.04, but this is more of a functionality question rather than OS specific I think.

There is software thats quite expensive which converts text to speech (subliminal messages) and sends them to 20k hz, at the edge of human hearing, for the purpose of creating self-help subliminals. I’d like to do that on Audacity if possible. I understand its a bit… out there, and thats fine, I’d appreciate the help anyway :slight_smile:

I’m aware that there is a pitch bending function in audacity but is there any way to play the audio at 20k hz?


Any ideas? Thanks

I don’t think the problem is going to be Audacity. There’s very little about your computer that’s going to be happy working up there. 20KHz is where the anti-aliasing, dither and error correction live. Nobody is expecting actual performance or show.

There’s another problem the audio people insist on presenting. How do you test it? There’s extensive testing and quality-control things you can do to make sure your piano solo or song worked out exactly perfectly—a lot of them built into Audacity. How do you test if your subliminal messages worked?

If you give us the other half of the process, we’ll be right there.


The upper frequency limit of digital audio is half the sample rate. For a sample rate of 44100 Hz (44.1 kHz), the absolute limit of frequencies that are supported is 22050 Hz (22.05 kHz). In practice, the limit is a little lower (around 20 kHz). For higher audio frequencies (ultrasonic), you need to use a higher sample rate.

Note that frequencies above 20 kHz are inaudible to humans, and there is no “evidence” (other than unsubstantiated anecdote) that ultrasonic sound has any conscious, subconscious or unconscious influence on humans, unless at extreme intensity which can cause heating effects and ultimately burning.

“Silent subliminals” is a technique that modulates audio with a high frequency carrier wave (usually “amplitude modulation”), in the (unreasonable) blind belief that by some unknown mechanism, the subconscious mind will be able to “hear” the ultrasonic sound, demodulate it, comprehend the “message” and be influenced by that message.

See here for more information about how to create “silent subliminals” with Audacity: