Listening Stones


Listening Stones, St. Vrain Greenway, Longmont, Colorado

Granite river boulders, wood, flagstone. 1997.

This sculpture uses a parabolic sound mirror carved into boulders to dramatically magnify the sound of a nearby stream for listeners. It is inspired by satellite dishes, the seating in choir lofts where curved walls reflect sound and the antique hand-held sound magnifiers used in the days before hearing aids. The concept of sound reflection has been known for centuries, such as at the Whispering Wall in China. … Now, parabolic sound mirrors are found at children’s playgrounds and in dish microphones at sporting events. The creative aspects of this sculpture are threefold […more at Robert Tully Artworks]

Listening Vessels at the San Francisco Exploratorium

Listening Vessels consists of two large parabolic reflectors set at least 50 feet apart which act as mirrors to reflect sound from one to the other. Two people sit opposite each other at approximately the focal point for each reflector, so that the sound coming from each reflector is focused at this point, allowing each visitor to clearly hear the other’s voice, even at a very low decibel in spite of the distance separating the vessels.
Source: The Exploratorium