I’m ever so slightly suspicious of the “low frequency sound weapon” aspect because that typically takes a lot of energy (I’m speaking from an audio background). However the reports of feeling uneasy do match that of infrasound… yet typically (based on what I’ve read) infrasound doesn’t have an instant reaction but takes some time for people to feel it.
https://en.m.wikipedia.org/wiki/Directed-energy_weapon has a lot more info if anyone is interested.