Hi. Been using audacity off and on for years for various projects, learning little by little over time. I’m back to it, downloaded the latest version and working on subliminal messages and isochronic tones and such.
I saw a post for an old version of audacity about silent subliminal messages, but wasn’t sure if that still applied to this new version of audacity.
My goal is to lower the frequency of the audio to just below the human range of hearing, like 15khz or 14khz. But I’m not at all sure about how I’d go about doing that. After that, it’s just a matter of adding the fluff. But getting past this frequency hurdle has been something I’ve been struggling with. So I figured I’d ask the gurus. Any information/assistance would be very welcome. Thanks much!
I added my operating system upon registering, but I’ll put it here too. Windows 10.
I guess my question is regardless of whether speakers can get that low. The method is more important than the other details for right now. So, I guess, let’s pretend that my goal is 30hz, or 40hz. Let’s say my lowest range of hearing is 50hz and I want to get the messages to 40hz. The method and an understanding of the variables is really what I’m looking for. That way, let’s say my lowest personal range of hearing is 70hz, I can set the messages to 60hz.
What sort of “messages”? Speech?
You could pass speech through the “Walkie Talkie” filter (In the “Equalization” effect)
and then slow it down with the “Change Speed” effect set to “Percent Change: -99.000”.
That will give you a frequency band-width of about 1 to 20 Hz.
Sorry but that is physically impossible.
In order to communicate words requires a certain amount of “data” (whether that be digital or analog data). A band-with of 20 Hz does not provide enough data per second to carry speech in real time. Apart from that, frequencies below 20 Hz may be “felt” as vibration, but are too low to “hear”.
That’s assuming that my lowest range of hearing is 20hz. If more realistically my lowest range of hearing is 200hz, then it’s not as inconceivable, I’d think. Again, what I’m looking for is the method and an understanding of the variables. If it’s possible to change the frequency of a speech file (without changing the speed of it) to 300hz, I’d like to know how. Even if the knowledge isn’t useful in the way I’d hoped, it’ll still teach me the methodology and then maybe I can change my expectations to fit “what’s possible,” if that makes sense.
I guess maybe I should be asking about the alternative as well. Let’s say we get nowhere with ultra low frequencies, how do I change the frequency of the audio file to be just above human range of hearing? Say, above 20khz. Normal speech speed, but higher in frequency; dog range of hearing, but just outside of human. Thanks!
With the “Change Pitch” effect. However, in the process you will lose at least 85% of the audio information.
Low frequency has a long wavelength whereas high frequency has a short wavelength. The wavelength is the distance between one oscillation and the next. To lower the frequency to 300 Hz requires shifting the pitch by at least 85%, which means that the oscillations need to be stretched to about 6.7 time their original length. In order to perform that stretching without reducing the speed requires that some of the audio has to be thrown away in order to make space for the longer wave cycles. In fact 85% of the audio has to be discarded. That leaves just 15% of the original data, which is simply not enough to be ineligible.