Mysterious hum driving people crazy around the world

It creeps in slowly in the dark of night, and once inside, it almost never goes away. It`s known as the Hum, a steady, droning sound that`s heard in places as disparate as Taos, N.M.; Bristol, England; and Largs, Scotland. But what causes the Hum, and why it only affects a small percentage of the population in certain areas, remain a mystery, despite a number of scientific investigations. Reports started trickling in during the 1950s from people who had never heard anything unusual before; suddenly, they were bedeviled by an annoying, low-frequency humming, throbbing or rumbling sound. More