During ritual ceremonies, the ancient Aztec civilization used a “death whistle” — a haunting instrument shaped like a human skull. Its eerie, high-pitched scream is not just a product of its unique ...

Over 70 years ago, Roald Dahl proposed that plants could scream in a fictional story called The Sound Machine. He suggested they could shriek — a high-pitched shriek undetectable to the human ear.

If you have ever been awake late at night and heard a strange, high-pitched scream echoing through the darkness, you might have wondered what it was. Many people describe it as frightening, almost ...