Teacher:Given a scientific passage and an answer, generate a question for the given answer.
Teacher: Now, understand the problem? Solve this instance: Passage: Ultrasound is sound that has a wave frequency higher than the human ear can detect. It includes all sounds with wave frequencies higher than 20,000 waves per second, or 20,000 hertz (Hz). Answer: ultrasound
Student:
What do you call sound that has a wave frequency higher than the human ear can detect?