Nazgul Screech

The Nazgul screeching. It's so horrible that in universe it causes people to just fall where they are and scream while covering their ears. Created by recording and blending numerous sounds, including co-producer Fran Walsh screaming. She had a throat infection at the time. Fans joked that Jackson got her to make that sound by telling her he was going to do a film of The Silmarillion next.

Example of:
Hell Is That Noise