This article discusses listening that is appropriate to sound art and the associated changes in the paradigms, or thought patterns, that occur so often when we move from visual to aural perception. The distinction between historically accepted and rejected sounds is used to show how putting sounds in cages has fashioned a form of listening and of life. Twentieth-century experimental music and, especially, the music and the reflections of John Cage have opened these cages of sound and at the same (...) time weakened the visual paradigm for intellectual knowledge. This article examines sound art as a place where artistic practices coincide with certain theoretical issues centered on sound. The centrality of sound is approached first, and music and sound art are discussed in relation to space. Second, the attention to sound in the reception of prominent examples of sound art focuses on site-specific relationships with the city and with listening. The article concludes by affirming the need for an aesthetic reflection that takes into consideration the implications of these profound transformations. However, that is another cage yet to be opened. (shrink)