When this happened elsewhere several months ago, wasn’t it determined that some electronic equipment was clashing or phasing in such a way that it caused some sort of high-pitched or strobing “sound” that made many people nauseous or giddy? Not intentional, not spying, just an odd electronic coincidence. And yes, hysteria is always a possibility. (PS: Just wait ‘til 5G is up and running! All hell’s gonna break loose.)
Must be the “brown noise.”