Are you one of the sensitive? Scientist Geoff Leventhall estimates that nearly 2.5 percent of the population may have a lower than average frequency threshold, meaning they can hear — and so they are bothered by — low sounds that most other people cannot even begin to perceive. Normally this sensitivity causes only an occasional source of discomfort, such as when a big diesel truck passes on the highway, but for those living near one of the planet’s rare “hum” spots, all pleasure in life may slowly erode until existence is nothing more than a painful chore…

Complete article: “How The ‘Hum,’ A Low Frequency Sound Heard Round The Globe, Affects The Health Of The Sensitive“, Susan Scutti, Medical Daily.