The Hum: Low-Frequency Invasive Humming. The Hum or the Bristol Hum as it is sometimes called is a low-frequency humming that is only ever heard indoors and doesn’t seem to have every been recorded as been heard outside. The Hum is a phenomenon that has been reported in both the UK and the US… People that hear the hum say that it never goes away, and it seems to get louder for the sufferer at night! This constant humming has caused a number of people to go insane and in some cases, has even driven some sufferers to take their own life! I truly couldn’t begin to imagine how terrible this must be I think we have all had a ringing in our ears before, but this must be unbearable. The people that do suffer with this invasive hum all get driven to a point of despair and accompanied with the other symptoms such as headaches, sickness, dizziness and even nosebleeds, it’s no wonder that many people who hear the hum go on to develop depression. Many experts have investigated the strange phenomenon known as the hum and at first, they believe that people were suffering from tinnitus but after many test and investigations it’s been found that the people who do hear the hum have normal hearing and don’t suffer from tinnitus. So, what could it be? We are talking about a hum that can only be heard indoors, not everyone can hear it and the people that do hear it have completely normal hearing. All attempts to record the hum have failed – and it is agreed by many specialists and researches have all agreed that the hum is a real phenomenon. We would love to hear what you think on this. Is it a real phenomenon and the hum is for some reason only heard by certain people and not everyone? Could it be psychological? or something else, something more sinister! What are your thoughts?