Redundancy Gains of Multimodal Alarms Across Flight-Task Variants: An Empirical Study

To address limits of conventional visual–auditory alarms during multitasking and sudden flight events, this study examined redundancy gains from tactile multimodal alarms. Using the Open‑source Multi‑Attribute Task Battery platform, we systematically evaluated the performance of uni-modal, bi-modal, and tri-modal alarm configurations across six simulated flight task variants. The findings indicate that multimodal alarms with an additional tactile channel generally enhanced redundancy gains across task variants. Specifically, multimodal alarms were associated with reduced choice response times, improved subjective user experience, and enhanced multitasking efficiency. Among the tested configurations, the tri-modal alarm yielded the greatest redundancy gains without imposing additional workload in multitasking scenarios. Nevertheless, under the most cognitively demanding triple-task condition, the tri-modal configuration resulted in a higher error rate, suggesting potential tactile interference when workload reached a critical threshold. Overall, these findings provide empirical support for the integration of tactile channels in the development of next-generation cockpit alarm systems.