ABSTRACT
Audio surveillance goes beyond the monitoring of rooms and phones. Audio devices are sometimes used for associates to communicate while monitoring a situation in other ways. Audio analytics is digital processing of sound to improve its quality or informational content or to select pertinent sections to emphasize, catalog, or store. Smartphones can be set down next to someone on a bench or at a table as an audio eavesdropping device and the conversation recorded as a digital file. Audio surveillance encompasses sounds humans can hear and sounds outside the range of human hearing. The simplest form of audio surveillance is human eavesdropping–cupping an ear, listening through a peephole, sidling up behind conversants, listening in on a second telephone, or putting an ear to the floor. Audio surveillance is no longer a local phenomenon, either physically or temporally. Videocams and cell phone microphones can be activated remotely, even if the owner isn’t actively using the device at the time.
