The parabolic shape of this pair of sculptures amplifies sound by reflection: Incoming sounds reflect from the surface of each vessel and get focused to a single spot called the focal point.
The seats in each vessel are carefully situated to put this focal point roughly in the location of your own ears, allowing you to hear the faintest whisper—loud and clear—from across a crowded room.
The parabolic shape of the Listening Vessels serves to redirect sound to a signal point called the focal point—here labeled with an F. (click image to enlarge)
Before the invention of radar, acoustic mirrors made of concrete gave early warning of incoming enemy aircraft by concentrating the sound of their engines. (click image to enlarge)
Radio telescopes and satellite dishes collect and focus electromagnetic waves in the same way that the Listening Vessels focus sound waves.
In architecture, curved walls and domes can create acoustic effects similar to what you experience here. Statuary Hall, in Washington, D.C.’s Capitol Building, is legendary for its tricky acoustics. A whisper on one side of this half-domed room can be heard more than 15 meters (about 50 feet) away.