Imagine lying in bed at night and you hear a noise. It’s not your phone. It’s not anything in your room. You open the window, nothing.

So you decide to investigate the house, all the while pressure builds up in your head.

There’s nothing out of the ordinary. Feeling more and more stressed and irritated, you turn off the fridge, with no success. The dishwasher? Nope.

Eventually you collapse onto the bed, tired and defeated, having achieved nothing in your search.

The sound continues.

One person who is researching what is called “The Hum” and why only some of us suffer is Dr. Glen MacPherson, lecturer at the University of British Columbia.

First aired: 29/10/16