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==Modern uses==
[[Image:Whispering dish, Jodrell Bank.jpg |thumb|right|A parabolic whispering dish that's part of an installation at [[Jodrell Bank]] Observatory.]]
Parabolic acoustic mirrors called "whisper dishes" are used as participatory exhibits in science museums to demonstrate focusing of sound. Examples are located at Bristol's [[We The Curious]], [[Ontario Science Centre]], Baltimore's [[Maryland Science Center]], Oklahoma City's [[Science Museum Oklahoma]], San Francisco's [[Exploratorium]],<ref>[http://www.exploratorium.edu/cmp/exhibits/l/listening_vessels.html Exploratorium ''Listening Vessels'' exhibit] {{webarchive |url=https://web.archive.org/web/20070807234329/http://www.exploratorium.edu/cmp/exhibits/l/listening_vessels.html |date=August 7, 2007 }}</ref> the [[Science Museum of Minnesota]], the [[Museum of Science and Industry in Chicago]], [[Pacific Science Center]] in Seattle, [[Jodrell Bank Observatory]], [[St. Louis Science Center]], and [[Parkes Observatory]] in Australia.
A pair of dishes, typically {{convert|2|to|3|m|ft|0|abbr=on}} in diameter, is installed facing each other, separated by around a hundred metres. A person standing at the focus of one can hear another person speaking in a whisper at the focus of the other, despite the wide separation between them.
[[Parabolic microphone]]s depend on a parabolic dish to reflect sound coming from a specific direction into the microphone placed at the focus. They are extremely directional: sensitive to sounds coming from a specific direction. However, they generally have poor bass response because a dish small enough to be portable cannot focus long wavelengths. Small portable parabolic microphones are used to record wildlife sounds such as birdsongs, in televised sports events to pick up the conversations of players, such as in the huddle during American Football games, or to record the sounds of the sport, and in audio [[surveillance]] to record speech without the knowledge of the speaker.▼
▲[[Parabolic microphone]]s depend on a parabolic dish to reflect sound coming from a specific direction into the microphone placed at the focus. They are extremely directional: sensitive to sounds coming from a specific direction. However, they generally have poor bass response because a dish small enough to be portable cannot focus long wavelengths.
Small portable parabolic microphones are used to record wildlife sounds such as bird song, in televised sports events to pick up the conversations of players, such as in the huddle during American Football games, or to record the sounds of the sport, and in audio [[surveillance]] to record speech without the knowledge of the speaker.
==Locations==
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