There was actually a story on 60 minutes just last night about this very thing. They did interview people who have been targeted by “acoustic” weapons.
I've always thought it was a side effect of some kind of bug malfunctioning if it was real.
Maybe that's what it started out as, and now Russia is weaponizing the bug in their spy equipment.
Like that unpowered wooden seal that would bounce back audio if you blast it with ultrasound just right. If they do too much, it can effect people. So after finding out it can effect people.... Russia being Russia is blasting people to cause harm