Visual Coding Using Flashing Lights 1

Abstract

An investigation of the feasibility of an alarm system employing visual signals was made. Using flash rate, values for four easily discriminable signals were established. In addition, minimum effective intensities for the four signals were obtained for the entire range of ambient illuminations associated with the operational situation. In a separate study, it was shown that little training was required to learn the signal code and once learned the code was maintained with little or no retention loss over the length of the experiment. The alarm system in its final form was used under both simulated work and actual shipboard conditions and was found to be effective as an attention-getting device and as a message source.