What is the most annoying sound in the world?  If you guessed nails on a chalkboard, you’re wrong. A group of neuroscientists tested which sounds most upset the human brain, they discovered that the most annoying sound in the world is a knife rubbed against a drinking glass.

Here are the top 10 most annoying noises:

1. A knife on a bottle
2. A fork on a glass
3. Chalk on a blackboard
4. A ruler on a bottle
5. Nails on a blackboard
6. A female scream
7. An anglegrinder (a power tool)
8. Squealing brakes on a bicycle
9. A baby crying
10. An electric drill

On the opposite end of the spectrum, these are the four sounds that are the least irritating:

1. Applause
2. A baby laughing
3. Thunder
4. Water flowing  (unless you have to use the bathroom we’re guessing!)

(Smithsonian)