Thousands of people across the world have experienced it. You are lying in bed, late at night, and all is quiet except for a persistent and annoying (and quite spooky) humming sound.
This often keeps the victim awake for hours, and if they venture outdoors to try and discover the source of this mysterious hum it sounds quieter than it does inside.
In the 1970s, the city of Bristol was particularly afflicted, with up to 1000 people saying they could hear a humming sound at night.
Many theories have been put forward as to what causes it, from military activity and central heating systems to aliens and UFOs.
It has also been noted that after the 9/11 attacks, many Americans who had suffered from "The Hum" said that the mysterious sound has suddenly vanished.
Now, a doctor at a Cambridge hospital thinks he has discovered the cause...
Have you heard The Hum? The throbbing noise that just won't go away?
By Michael Hanlon , Science Editor
20th May 2009
Daily Mail
It's a menace that drives thousands to distraction and has been blamed on everything from UFOs to nuclear submarines. A scientist claims he's found the cause. Our man (who's heard it) listens in...
Michael Hanlon
To the unaffected, it sounds suspiciously like a case of mass hysteria. It is the stuff of dark conspiracies, cover-ups and general spookiness. But to 'sufferers', if that is the right word, this mysterious throbbing noise, which never goes away and exists right on the brink of perception, is real and concrete enough to ruin lives.
I have only experienced 'The Hum' - at least, I assume it was The Hum - once. I was about eight or nine years old, and I remember becoming aware of a rumbling noise, half-way between a distant pneumatic drill and a badly tuned diesel engine.
It happened in the dead of night, and kept me awake for hours.
I opened my window and turned my head this way and that in a futile attempt to locate the origin of the sound, which seemed to be emanating from the end of our quiet street.
'The Hum' has been blamed on many things, but one thing is sure: It is maddening for those who hear it
In desperation, I woke up the rest of my family to see if they could hear it - they couldn't - and I even got dressed and went out in search of the noise, accompanied by the dog.
It was all to no avail. No one could hear what I was hearing (not even the dog), and I never got to the bottom of the mystery of the noise. It returned on a couple of subsequent evenings and then vanished, never to be heard again - by me at least.
For the noise wasn't, it turns out, just a figment of my imagination. Indeed, The Hum - as it is now known - is a mysterious phenomenon which has been reported by thousands of people around the world.
More..
They describe it as a persistent, low-level and low-frequency noise. It is not audible to everyone and, most importantly, has no obvious source.
Until now. After exhaustive research, a doctor in Cambridge says he has finally solved the mystery.
Unfortunately, few are likely to be satisfied by his solution (more of which later).
Over the years, dozens of explanations have been put forward for The Hum. Some sensible, some mundane, a few downright crazy. Many have fallen by the wayside.
Either way, The Hum has been the subject of conspiracy theories galore - and has driven a few to the edge of madness.
Hums - this is clearly a multiple phenomenon - come and go. In the Seventies, the city of Bristol was afflicted, with hundreds of people complaining of a persistent sound that caused sleeplessness, headaches and even nosebleeds.
When a local newspaper asked people to write in if they had heard the throbbing, rhythmic sound, nearly 1,000 did so. No official explanation was ever found.
Some suspect flying saucers could be to blame for the irritating noise
So what does cause The Hum? It is generally described as being a low-frequency sound of a few tens of hertz (around 20 hertz, or 20 vibrations per second, forms the lower limit of normal human hearing).
This would appear to rule out the most obvious cause: the ear disorder, tinnitus, which usually manifests itself as high frequency 'ringing in the ears'.
What's more, many people report that The Hum is more intense indoors than out.
In my case, I could still hear it when I left the house - although it was certainly quieter.
Many sufferers also claim that ear plugs fail to block it out, and a few even claim that they can actually 'feel' the vibrations.
Of course, there are plenty of rather mundane theories for the cause of The Hum. After all, the modern world is a noisy place.
Cars, trucks, rail traffic and the general hubbub of city life can easily generate whole layers and sub-layers of sound, easily perceptible as a sort of low-level white noise.
Low-frequency sounds also carry further, and through more materials, than high-frequency noises. That is why we can hear the bass notes of a car stereo from further away than the treble tones.
Factory noises, the sounds emitted by high-tension powerlines and the various machines and devices which form the bedrock of the modern urban environment, such as central heating and air conditioning systems, water pipes, wind turbines and fans, can all carry a long way and may be amplified by walls, foundations and enclosed spaces in ways that are not yet entirely understood.
Indeed, a Hum has often been pinned down to a single cause. On Hawaii, for example, one widely heard case of The Hum was traced to volcanic, underground rumblings. In others, an electricity generating plant, a transformer sub-station or a power plant cooling tower have been found to be the source.
There were also intriguing reports that immediately after the September 11 attacks on New York, some Americans who had hitherto been haunted by The Hum claimed that it had stopped, at least temporarily. This suggests that The Hum may also be caused by aircraft, which were grounded in the U.S. for several days following the attacks.
But this does not explain all cases of The Hum. For some cannot be picked up by electronic microphones, no matter how sensitive or advanced. Which is where we stray into the dark world of conspiracy theory and spook story.
Many Hum 'victims' blame covert military activity, secret submarine communication devices, nuclear experiments and even orbiting satellites for the nuisance.
There are even paranoid theories that The Hum is some sort of sinister psychological experiment being performed by dark forces in the government or the security services. Aliens and UFOs also inevitably stray into the frame.
'The Hum' was rumoured to have stopped temporarily after the September 11 attacks on New York and Washington. Aircraft in the US were grounded after the terrorist strike
And some Hum victims are clearly lunatics. I used to get letters from a man convinced that the noises he was hearing were the result of a secret military experiment whereby radio receivers had been implanted into his brain, a relatively common delusion in the radar age.
But what does our Cambridge doctor have to say on the subject? Well, Dr David Baguley, of Addenbrooke's Hospital in Cambridge, thinks that in many cases, The Hum can be explained by boring old oversensitive hearing.
He says that our hearing has evolved to become especially acute at times of extreme danger or stress, times when, quite literally, you can hear the proverbial pin drop.
His theory is that in some people this hyper-sensitivity remains 'switched on' at all times.
'It becomes a vicious cycle,' he says. 'The more people focus on the noise, the more anxious and fearful they get, the more the body responds by amplifying the sound and that causes even more upset and distress.'
This sounds plausible enough, and indeed Dr Baguley says that he has managed to use relaxation techniques to help people shed the perceived noise that has made their lives a misery.
But this rather everyday explanation will not satisfy everyone.
Just as weather balloons, the planet Venus and optical illusions can explain away most, but not all, UFO sightings, so some people will always maintain that their hum represents something rather more sinister than over-sensitive hearing.
And as for my Hum? No idea. All I can say is that I was very grateful when it finally left me in peace
dailymail.co.uk
This often keeps the victim awake for hours, and if they venture outdoors to try and discover the source of this mysterious hum it sounds quieter than it does inside.
In the 1970s, the city of Bristol was particularly afflicted, with up to 1000 people saying they could hear a humming sound at night.
Many theories have been put forward as to what causes it, from military activity and central heating systems to aliens and UFOs.
It has also been noted that after the 9/11 attacks, many Americans who had suffered from "The Hum" said that the mysterious sound has suddenly vanished.
Now, a doctor at a Cambridge hospital thinks he has discovered the cause...
Have you heard The Hum? The throbbing noise that just won't go away?
By Michael Hanlon , Science Editor
20th May 2009
Daily Mail
It's a menace that drives thousands to distraction and has been blamed on everything from UFOs to nuclear submarines. A scientist claims he's found the cause. Our man (who's heard it) listens in...
Michael Hanlon
To the unaffected, it sounds suspiciously like a case of mass hysteria. It is the stuff of dark conspiracies, cover-ups and general spookiness. But to 'sufferers', if that is the right word, this mysterious throbbing noise, which never goes away and exists right on the brink of perception, is real and concrete enough to ruin lives.
I have only experienced 'The Hum' - at least, I assume it was The Hum - once. I was about eight or nine years old, and I remember becoming aware of a rumbling noise, half-way between a distant pneumatic drill and a badly tuned diesel engine.
It happened in the dead of night, and kept me awake for hours.
I opened my window and turned my head this way and that in a futile attempt to locate the origin of the sound, which seemed to be emanating from the end of our quiet street.
'The Hum' has been blamed on many things, but one thing is sure: It is maddening for those who hear it
In desperation, I woke up the rest of my family to see if they could hear it - they couldn't - and I even got dressed and went out in search of the noise, accompanied by the dog.
It was all to no avail. No one could hear what I was hearing (not even the dog), and I never got to the bottom of the mystery of the noise. It returned on a couple of subsequent evenings and then vanished, never to be heard again - by me at least.
For the noise wasn't, it turns out, just a figment of my imagination. Indeed, The Hum - as it is now known - is a mysterious phenomenon which has been reported by thousands of people around the world.
More..
They describe it as a persistent, low-level and low-frequency noise. It is not audible to everyone and, most importantly, has no obvious source.
Until now. After exhaustive research, a doctor in Cambridge says he has finally solved the mystery.
Unfortunately, few are likely to be satisfied by his solution (more of which later).
Over the years, dozens of explanations have been put forward for The Hum. Some sensible, some mundane, a few downright crazy. Many have fallen by the wayside.
Either way, The Hum has been the subject of conspiracy theories galore - and has driven a few to the edge of madness.
Hums - this is clearly a multiple phenomenon - come and go. In the Seventies, the city of Bristol was afflicted, with hundreds of people complaining of a persistent sound that caused sleeplessness, headaches and even nosebleeds.
When a local newspaper asked people to write in if they had heard the throbbing, rhythmic sound, nearly 1,000 did so. No official explanation was ever found.
Some suspect flying saucers could be to blame for the irritating noise
So what does cause The Hum? It is generally described as being a low-frequency sound of a few tens of hertz (around 20 hertz, or 20 vibrations per second, forms the lower limit of normal human hearing).
This would appear to rule out the most obvious cause: the ear disorder, tinnitus, which usually manifests itself as high frequency 'ringing in the ears'.
What's more, many people report that The Hum is more intense indoors than out.
In my case, I could still hear it when I left the house - although it was certainly quieter.
Many sufferers also claim that ear plugs fail to block it out, and a few even claim that they can actually 'feel' the vibrations.
Of course, there are plenty of rather mundane theories for the cause of The Hum. After all, the modern world is a noisy place.
Cars, trucks, rail traffic and the general hubbub of city life can easily generate whole layers and sub-layers of sound, easily perceptible as a sort of low-level white noise.
Low-frequency sounds also carry further, and through more materials, than high-frequency noises. That is why we can hear the bass notes of a car stereo from further away than the treble tones.
Factory noises, the sounds emitted by high-tension powerlines and the various machines and devices which form the bedrock of the modern urban environment, such as central heating and air conditioning systems, water pipes, wind turbines and fans, can all carry a long way and may be amplified by walls, foundations and enclosed spaces in ways that are not yet entirely understood.
Indeed, a Hum has often been pinned down to a single cause. On Hawaii, for example, one widely heard case of The Hum was traced to volcanic, underground rumblings. In others, an electricity generating plant, a transformer sub-station or a power plant cooling tower have been found to be the source.
There were also intriguing reports that immediately after the September 11 attacks on New York, some Americans who had hitherto been haunted by The Hum claimed that it had stopped, at least temporarily. This suggests that The Hum may also be caused by aircraft, which were grounded in the U.S. for several days following the attacks.
But this does not explain all cases of The Hum. For some cannot be picked up by electronic microphones, no matter how sensitive or advanced. Which is where we stray into the dark world of conspiracy theory and spook story.
Many Hum 'victims' blame covert military activity, secret submarine communication devices, nuclear experiments and even orbiting satellites for the nuisance.
There are even paranoid theories that The Hum is some sort of sinister psychological experiment being performed by dark forces in the government or the security services. Aliens and UFOs also inevitably stray into the frame.
'The Hum' was rumoured to have stopped temporarily after the September 11 attacks on New York and Washington. Aircraft in the US were grounded after the terrorist strike
And some Hum victims are clearly lunatics. I used to get letters from a man convinced that the noises he was hearing were the result of a secret military experiment whereby radio receivers had been implanted into his brain, a relatively common delusion in the radar age.
But what does our Cambridge doctor have to say on the subject? Well, Dr David Baguley, of Addenbrooke's Hospital in Cambridge, thinks that in many cases, The Hum can be explained by boring old oversensitive hearing.
He says that our hearing has evolved to become especially acute at times of extreme danger or stress, times when, quite literally, you can hear the proverbial pin drop.
His theory is that in some people this hyper-sensitivity remains 'switched on' at all times.
'It becomes a vicious cycle,' he says. 'The more people focus on the noise, the more anxious and fearful they get, the more the body responds by amplifying the sound and that causes even more upset and distress.'
This sounds plausible enough, and indeed Dr Baguley says that he has managed to use relaxation techniques to help people shed the perceived noise that has made their lives a misery.
But this rather everyday explanation will not satisfy everyone.
Just as weather balloons, the planet Venus and optical illusions can explain away most, but not all, UFO sightings, so some people will always maintain that their hum represents something rather more sinister than over-sensitive hearing.
And as for my Hum? No idea. All I can say is that I was very grateful when it finally left me in peace
dailymail.co.uk
