The Guardian:

Scientists from Newcastle University have drawn up a table of the least pleasant sounds we may encounter as part of everyday life.They tested reactions to 74 different noises both in outward response and more closely via small changes in the brain.The results are published in the latest issue of the Journal of Neuroscience and show, among other things, that acoustically anything in the frequency range of around 2,000 to 5,000 Hz was found to be unpleasant.

I’m not going to tell you what they are – you’ll have to click through to see for yourself. Then, you will be forced to listen to them out of curiosity. Then you will find yourself in pain – just like I was.