Video: Mysterious sounds heard across Western Netherlands

Strange sounds heard across the Western Netherlands over the past few weeks has the internet community speculating on what on earth, or outside it, the noises could be.

The sounds were heard in Gouda, Pijnacker and Bleiswijk, among others, AD reports. The video below was recorded in Gouda.

A popular online theory is, of course, aliens. Another theory blames experiments by the American army. A professor Khalilov from Azerbaijan thinks it may be caused by powerful eruptions from the sun or "powerful energetic processes" from the bowels of the earth.

The Royal Netherlands Meteorological Institute considers the last theory at least unlinkely. "I can not imagine that solar flares or geomagnetic fields are responsible for this kind of noise", geophysicist Laslo Evers said to the newspaper. "I've never found evidence of that at least."

He cannot say with certainty what is causing the noise. "As it's been observed by many people over a wide area, it must have a large source. I myself think that it comes from a large industrial complex. The port of Rotterdam perhaps?"