While there's no answer to the philosophical questions laid down by John Cage's classic "4:33," this of course hasn't stopped many artists from taking a hearty stab at a conceptual rebuttal anyway. Some (perhaps without even trying) get closer than others.
British artist and musician David Cunningham takes the natural "silence" of random public and private spaces, and subtly amplifies it to the foreground. Using a location's own real-time audible (and inaudible) "background" noise as a source, Cunningham installs simple equipment (a microphone/speaker/amplifier/noise gate set-up) that records, amplifies and loops the natural sounds refracted within each location, feeding it back to the space itself in real time, re-focusing people's ears to "listen" to sounds in quiet spaces where they might not normally do so. The goal of his Activated Space project is "...to develop and present a series of installations that alter an architectural space to allow its resonant frequencies to become audible and interactive."
What kind of public spaces does he aurally reconfigure? Random elevator corridors in apartment buildings in Birmingham, unsuspecting stairwells of buildings in Tokyo, public squares in Copenhagen, outside the walls of museums in Helsinki, hidden warehouses in Sydney, exteriors of architecture schools in London, city sidewalks, and even British courtrooms have already caught pedestrians, occupants and passersby ears unaware due to his subtle manipulation of their normal acoustic habits. Although some of his work has appeared in galleries, the installations in public spaces are often unannounced, save for a simple place card nearby.
Cunningham documents all his installations at his Activated Space website. Be sure to check out the sound and video clips of his work in action (the one of the confused people in the elevator corridor is priceless).
Now we can all finally hear what Bionic Woman Jamie Sommers did all those years with her super-ear (was she the only one not bored at subsequent performances of '4:33'?)