My thinking on this question: I don't know the answer, but my gut says it's possible (though not too practical). While futzing with things like psk31, I've noticed that the sound level, even the audible sounds, the volume does not have to be very high at all if the devices are very close. For example, while setting up the 21 sat transfer audio file in the link up above, I used normal earbuds dangling over my laptops mic. I did that because the audio was too annoying my wife would have strangled me. I have rather poor hearing, but I could not audibly hear the sounds even though the data was being transferred earbud-->mic-->Fldigi to decode.

As far as outside the range of normal hearing thresholds, that's probably something for a ham radio person to answer. User bitpunkfm suggested waver (ggwave) over on nostr. I'd never heard of it, but it might be doing what you're describing with "ultrasonic" messages. See youtube vid, the first couple of tx you can hear, the ultrasonic message is at about the 33 second mark.

Convo on nostr: https://njump.me/nevent1qqs953da657ss86eq0dv49d5vrnqu6f70t3k57j6xnaluejaazvs3jqpzdmhxue69uhk7enxvd5xz6tw9ec82c30qgs9pk20ctv9srrg9vr354p03v0rrgsqkpggh2u45va77zz4mu5p6ccrqsqqqqqpfm4nnn