This happened to me too when I lived in a house near to local boiling station. Once the same truck parked with its engine on near the station (service or supply, maybe), my room had many points where you can easily get panic or stress attacks. It was probably focused infrasound, not high-pitch, but few hours after, especially in sleep, I began to feel it even without that truck. Self-deception is very inductive thing.

I think that the article describes the aftereffects of something like geological activity, so while its roots are real, the consequences are the product of "tired" minds. I heard also that if doctors allow their clients to speak about symptoms in waiting room, then many of them start having these "group symptoms" and diagnostics may go very wrong way.