A Mysterious Sound Is Driving People Insane – Nobody Knows What's Causing It 12 years ago
Blood-pressure + or - sinus-congestion?
Maybe some people begin to sub/consciously listen for their phone to buzz, vibrate or make a sound and notice the noise of air, static noise, computer fan hums, blood traveling inner ear?
Their utilities run @ 50hz. Maybe there's a conflict with older and newer products manufactured from other countries?
Maybe doppler radar.
Maybe dead air space.
Maybe they're not used to the sound of silence.