A Comparison of Small Sets of Voice versus Tone Warnings as a Function of Task Loading and Background Communication

Abstract : In support of the F/FB/EF-111 Digital Flight Control System Program Office, the present human engineering study evaluated the merits of voice versus tone warning systems in tems of pilot response time and response accuracy performance. Task loading and background communication were two other variables that were evaluated. Non-significant study results for the warning systems found in this study, suggest that for this small number of messages (four), neither a voice or a tone warning system has an advantage over the other. However, based on the present and previous research in the area of warning systems, and considering the total number of tone messages in the F-111, the long term benefits of implementing a voice warning system may be great in terms of reducing pilot workload. These study results demonstrated statistically significant main effects for task loading and background communication. Therefore, these results suggest that specifying pilots' response times for a time critical system, such as a ground collision advisory system, may require further consideration of relevant factors that have a significant influence on human reaction and response times. (FR)