Auditory Warnings in the Military Cockpit:: A Preliminary Evaluation of Potential Sound Types

This document reports the results of two experiments assessing the viability of speech, auditory icons (environmental sounds) and abstract sounds (complex tones) for use as auditory warnings in military cockpits. Experiment One evaluated the comparative ease of learning and retention of these three sound types, with the results demonstrating that speech warnings and auditory icons were learnt and retained with equal ease, while abstract-sound warnings were found to be learnt and retained with far greater difficulty. Experiment Two examined a user’s ability to respond to speech, icon and abstract auditory warnings under varying degrees of workload. The results of this experiment show that speech warnings provide an advantage in reaction time and response accuracy over auditory icon warnings, which in turn hold an advantage over abstract sounds. The results of these two experiments indicated that, under low levels of workload, speech warnings may prove to be an effective supplement to traditional visual warnings, while icons also warrant further investigation.