How to create subliminal mp3 for sleeping time?

I listen constantly ultrasonic subliminal create with audacity but i want to listen them also during night.
I know that ultrasoni subliminal work only at wav files, and now i want to write them at mp3 format for my mp3 player .
How can i produce them?
(sorry for my english but i’m italian xD )

So-called “mp3 players” will also play WAV files.

However if you use an “extreme” bit-rate when creating the mp3, the ultrasonic stuff will survive conversion to mp3…

[ BTW There’s no evidence the ultrasonic messages can be heard/understood by people :
being granted a patent does not mean the invention actually works ].

Just a thought:
Perhaps subliminal MP3s work in a similar way to homoeopathic medicine and it may not be necessary for the MP3 to actually contain any of the original audio.
If this is the case, then just exporting as a normal MP3 with no special considerations regarding the format will work just as well as, or even better than, a high sample rate WAV.

Placebo effect works for more than half of the population…

I was amazed a couple of weeks ago, when I came across a hardware device to create subliminal audio. And, no, it wasn’t new. It was 2nd hand and looked like it dated at least 20 years ago. Couldn’t tell what it was doing by looking at the knobs…