Overnight hum puzzles Castle Bromwich residents

MYSTERY: An apparently unexplained humming sound was previously the
subject of  an episode from classic science fiction series The X Files.

A STRANGE humming sound is disturbing the sleep of residents in and around Castle Bromwich.
Local people have taken to social media to complain of a persistent droning during the small hours of the night.
Theories abound about what is causing the commotion, which many have said is different from the rumble of motorway traffic.
Overnight roadworks, the sound of a local wood yard and aircraft engines being tested at Birmingham Airport are among the possible causes of the "low-bass" noise, which has also been heard in Smith's Wood and Castle Vale.
James Brown wrote: "Hard to pinpoint, it must be near someone's home...
"We can't all be hearing things. It seems to go on and on then stops. Drives you mad."
It is possible that the sound is another case of The Hum, a low-frequency drone which has baffled researchers for many years.
The phenomena - which caused enough of a stir in the 1990s to feature in an episode of The X Files - continues to divide opinion among scientists.
The first case to garner significant publicity in the UK was more than 40 years ago, when hundreds of people in Bristol were adamant they had heard the noise.
Some have suggested that gas pipes or power cables may generate a sound which isn't audible to everyone, although other experts have blamed tinnitus or oversensitive hearing.