Some of you first heard it in the 70s. One of you heard it on a hot summer’s day on Hampstead Heath, in London. And one of you even wrote a poem about it.
On Wednesday Philip Jaekl reported on a mysterious phenomenon known as the Hum. Up to 4% of people around the world are thought to hear the strange, low-pitched noise. Its actual source is unknown, though many hearers are in urban areas, suggesting it could be some form of noise pollution.
Anecdotes came thick and fast as “hum hearers” shared their experiences and tried to describe it. “An endless riff of heavy metal music … difficult to say if felt or heard,” said one. “An unmistakable mechanical ‘whirring’ hum,” said another. Locations varied – from the Cheshire countryside in the UK, to Chichagof Island off the coast of Alaska to a high-rise apartment block in Sydney, Australia.
It’s not the first time a hum has hit the headlines. In 2016 residents in the Canadian city of Windsor were plagued by a puzzling noise. A study later confirmed it was likely to be coming from a US Steel plant’s blast furnace operations on nearby Zug island.
This week readers proposed theories about what the mysterious worldwide hum is and several, more sceptical readers, cast doubt on the idea that it exists at all. While there was debate about whether the hum is in fact tinnitus, Glen MacPherson, a mathematics, physics, psychology, and Russian Language teacher and former Mathematics Education lecturer at the University of British Columbia (UBC), who has been investigating the Hum’s source, said: “As several posters mentioned, classic tinnitus is profoundly different from the Worldwide Hum.”
He added: “While it must be stressed time and again that there are many sounds created by human activity that can sound like the Hum, and it takes some effort and knowledge to track those sounds down. They range from electrical noise, pumps, industrial machinery, and so on. Once we eliminate those sources, we are left with the worldwide phenomenon that I am studying.”
“Genuine” Hum hearers, or not, here’s what our readers had to say on the matter:
What does it sound like?
Ozonelayer I used to live in central Liverpool and could often hear this strange hum in the middle of a quiet night, though my partner never could. To me, it sounded like a large diesel engine, probably a ship or a train both of which would be close by. However, after “suffering” this for months at a time I decided to do proper research into ship and train movements to try and isolate the cause – discovering that it was neither.
Some claimed it is tinnitus …
KaterinaDelina I’m interested to know how tinnitus has been excluded from the list of possible causes. Tinnitus can be a low pitched hum or a rumble, it’s not always ringing or high pitched. I have tinnitus and there are three different sounds – a high pitched whistle, a lower ringing, and a low rumbling.
But others disagreed
timbomachino I don’t think it’s tinnitus because that’s a very high frequency sound. I think we’re talking about 18Hz or lower, which is around the area of the fattest cathedral organ pipe. Those pipes are designed to be more “felt” than heard. However, because the frequency is right on the edge of human hearing, and we’re all different, only some of us can hear it. Whatever it is, and wherever it comes from, it’s bloody annoying if you can hear it.
Jaybee UK I moved to Bristol six years ago and started hearing this. Have been following the subject avidly since and very familiar with Glen’s research. For all those flippantly pointing the finger at tinnitus, or some other yet unexplained internally produced phenomenon, explain this: I can completely eliminate the hum by using silicon ear plugs. The hum I hear is largely omnipresent but only indoors. Often it starts at a certain time, usually between 2200-0100 but it also can be present throughout the day. It’s around the range of 50-60Hz.
Many have been left mystified by it
Nancyloh So glad to know there’s a name for it! I heard it three or four times in the ’70s. Each time it was at a different outdoor spot in Singapore. It wasn’t tinnitus or from within but out there. It was quite a loud and unmistakable mechanical “whirring” hum. The person I was with heard it too, and we joked about UFOS.
CitizenGlenn Yes, I have heard the “Hum” … I live in a high rise apartment near Sydney’s CBD, and a stone’s throw from the Southern Cross Drive, which I have long considered to be the cause. Interesting that one hypothesis mentioned in this article is high-speed traffic. The sound is like a low frequency hum of a propeller driven airplane that oscillates between a louder and a softer hum. At first, I thought it was an old DC3 or similar circling overhead, but it wasn’t that. I don’t hear it often but when I do, it is quite noticeable.
BroadfordBoy I first experienced this as a nocturnal phenomenon in the early 1960s when I lived on the edge of a large city – I know this because (I cringe to recall) I referenced it in a poem I wrote for the school magazine.
People say they hear it at different times of the day
Tintenfische The only time I don’t hear the hum is very early in the morning when the world is asleep.
Readers offer their own explanations …
LZephania A neurological “internally generated perception of sound” seems a likely explanation. There’s a variety of similar phenomenon known in medicine.
Sensel Could it be updates and use of high pressure natural gas lines in many cities and suburbs?
RoyfromBungay Maybe the Hum could be “beat frequencies”. When you have two (or more) sounds of different frequencies both present, a “beat frequency”, a further frequency of sound, is produced, being the mathematical difference. With there being a huge number of sources of urban sound with many different frequencies. Perhaps this could explain why several different observers perceive different frequency sounds.
Some places have their own “hum”
Trevor Hutton My father was a suffolk coastal child during WW2. He often referred to the “Suffolk Hum” or “Suffolk Noise” which, he said a small proportion of people could sense when he was a child and later on. There were rumours about it during the war such as the enemy tunnelling etc. One day I took the dog for an early walk about 5:30 am. And for the whole while and some time after I could sense a constand noise which I would liken to an endless riff of heavy metal music. But it was constant, directionless and difficult to say if felt or heard. It most definitely was not music, and I am convinced it was the Suffolk noise.
Sblejo Taos, New Mexico, not what would be described as a metropolis, is well-known for its “Taos hum”, I first heard about it in the 1970s, have never experienced it.