It fails on points one and two. Because it’s out in the public space the person has no solitude or seclusion, and there’s no intrusion into private affairs. They’re projecting sound, which assuming decibel levels are not over legal limits is perfectly fine, just because the sounds aren’t audible unless you’re a small 3D space doesn’t make it illegal, all sound is only audible in a 3D space, only difference is this one here is the size of your head.
Your parallel doesn’t work, this is something out in the public space, on a sidewalk. So any analogy that includes private property fails completely.
My mistake. Your interpretation is correct as I understand it.
After investigating the technology as presented we aren’t observing ultrasonics which are used to communicate within the cranium, rather a remote loudpeaker system using utrasonic waves as an intermediate transmission medium, which later attenuate predictably into audible harmonics. The ears still function in the hearing and communication process.
From the article, we are not speaking of 2 ultrasonic waves producing lower frequency audible frequencies, in which case the laws/ordinances/regulations governing such public volumes might be pertinent. The significance of the issue is a new form of communication bypassing normal modes of reception.
Audible sound is generally accepted as between the frequencies of 20Hz - 20,000 Hz. (Most sound reproduction rarely dips below 42 Hz, and most sound tests of adults show diminishing auditory perception with age at above 16,000 Hz)
Medical Ultrasonics are in the region of 20,000Hz - 3GHz. Metallurgical Ultrasonics focuses generally between 1-3GHz.
They are not audible frequencies. Hence the name, ‘ultrasonics’ (ultra- beyond, sonic- sound).
They can penetrate tissue. The area which is private is the person’s body, soul, and spirit. My understanding from the article was that the communication perceived as sound had been generated by ultrasonics and were received within the person’s cranium, not from the normal vibratory modes of the ear.