Q. You often read that a duck’s quack does not echo? Is it true? Why? A. This is a good example of a question that flies in the face of logic. It smells fowl. Echoes are a little bit like a reflection in the mirror. You look in a mirror, your reflection bounces back at you. Instead of being a light wave, though, an echo is a sound wave that bounces back after sound hits a solid object. Unless ducks are the vampires of the audio world, there just would be no logical explanation for having echo-proof quacks. Ducks also appear during the day, and if they were vampires, this couldn’t happen. Bottom line: The quack of a duck does indeed echo.