Whisper Dishes

The Whisper Dishes are parabolic dishes, meaning they are curved in the shape of a parabola. Parabola-shaped dishes collect, focus and amplify wave signals, including light waves, radio waves and sound waves.

WHAT TO DO

1. Face the center of a Whisper Dish
2. Keep your head about 1 foot away
3. Have a friend do the same at the other Whisper Dish
4. Talk to your friend…and listen to what they say back

HINT:  WHILE YOU TALK, STAY TURNED TOWARDS YOUR WHISPER DISH

HOW IT WORKS

Sound waves from your voice bounce off the curved, parabolic shape and travel parallel to the second Whisper Dish. The sound waves reflect to its focal point – the point where the sound waves converge.  If both of you are at the focal points you can hear each other clearly, even if you whisper!

DID YOU KNOW?

The Whisper Dish, also called a parabolic acoustic mirror, is a passive device used to reflect and focus wound waves.  Buildings around the world function as whisper dishes, including St. Paul’s Cathedral in London, the rotunda of the Missouri State Capitol, Statuary Hall in the U.S. Capitol, and the Temple of Heaven in Beijing.  Circular and ellipse-shaped walls in these buildings allows for whispered communication.