ABSTRACT The late 1920s yielded the development and construction of several large-scale “sound mirrors,” along the southeastern coast of Britain, aimed at intercepting sounds of approaching aircraft outside the visual range. A central mode in the design of these long-range listening devices emphasizes a sonic paradigm in which frequencies are considered in terms of corresponding physical sizes. By examining the case of the sound mirrors as a formative moment within the broader reconfiguration of listening habits, the author attempts to locate a shift in the grasp of space that occurs when an optic model of viewing is replaced with an acoustic model of listening, exposing a condition in which the close-at-hand and the far-off momentarily coincide.