Radiation Search and Detection by Ear and by Eye

Abstract

Most radiation monitors in use employ visual displays. In some cases the monitor has an auditory display, but even then the operators are usually instructed to rely mainly on the visual information. It is not clear, however, that the visual mode is to be preferred. The present project focuses upon the relative efficiency of various types of information that can be provided by radiation monitors. Two experiments were conducted. In the first, the subjects were asked to perform a search task. The second evaluated performance in a detection task. The main independent variable of interest in both experiments was information mode; that is, the mode of providing information about the radiation level. We compared three modes of providing the information: auditory, visual, and redundant (both auditory and visual). It was found that in the detection task the three modes of information resulted in identical levels of performance. In the search task, however, the auditory display resulted in a better performance than did either the visual display or the redundant condition. The results are consistent with the concepts of visual dominance and visual bias as suggested by Posner et al. (1976). The implications of the findings are discussed.