What is the mysterious ‘global Hum’ and is it simply noise pollution?

Up to 4% of people are said to hear a strange low-pitched noise known as the Hum, but no source has ever been found. City life is one possible cause Whenever I wake up it is there and it is unbelievably loud. When nobody else can hear it you think you are going nuts, and it just wears you down, says Simon Payne, 55, from Cambridgeshire. Payne is a hearer of the mysterious global phenomenon known as the Hum. I have been desperate to get away from it, so I have stayed with friends and even moved house. The Hum is experienced as a consistent, low-pitched noise, much like the sound of a large truck idling in a nearby parking …