The Hum (cont.)

Despite an extensive study being carried out, one which revealed that 2 percent of the populous reportedly heard the sound, the location and cause of this enigmatic noise was never discovered. The only kernel of an explanation put forward was that the area had slightly higher than normal electromagnetic field levels but that quickly attributed to being the result of local power lines.

There have been quite a few explanations put forward over the intervening years. Some blame industrial equipment, while other possible explanations include high-pressure gas lines, electrical power lines and wireless communication devices. Low-frequency electromagnetic radiation, seismic activity, tinnitus have also had fingers pointed at them, but as yet, none have been definitely proven to be the cause.