In the ninth grade I was in chorus for a few months until the instructor offered me an “A” for the rest of the year if I dropped her class. True story. You would think a guy who likes music but can’t sing would at least enjoy humming, but that depends. Research has shown that humming can cause anxiety, depression, insomnia, and in some cases, ghosts. Also true — though of course I left out a few details there.
Humming to a song because you don’t know (or can’t sing) the words is harmless, unless maybe it is incessant and happens to irritate your co-workers. But many industrial processes like blast furnaces, cooling towers, and giant compressors and vacuum pumps can emit low-frequency or infrasound hums able to travel tens of miles. Because human-caused hums have unusually long wavelengths — in some cases more than a mile — the hum can travel easily over mountains and through buildings. » Continue Reading.