To address this issue, at least since Galileo developed the Galilean telescope in 1609, technological progress has concurrently developed numerous means of extending, enabling, and substituting our individual sensory system to detect many technologyderived hazards. As observed by Brown (2008, p. 55), “we test hypotheses about items we cannot detect with our unaided senses by introducing a device, or chain of devices, that yields an output we can detect.” We continue to develop ever more sophisticated sensory devices to detect many of the newly created dangers that we face in today’s world. This chapter considers some of the ways in which technology has enhanced or replaced humans’ sensory system so that we are better adapted to sense dangers in our contemporary world. The tables and summary texts in this chapter describe illustrative devices or techniques grouped according to the sensory subsystem that they were developed to augment or replace, together with brief descriptions of typical or potential applications.