Multimodal warnings to enhance risk communication and safety

•Multimodal displays incorporate audio and/or skin-based tactile cues.•Multimodal warnings useful where visual perception is busy, impaired, or nonexistent.•This paper explains how multimodal displays enhance safety and risk communication.•The authors describe design guidelines to effectively use multimodal warnings.•Conclusions and recommendations for future multimodal display research are presented.

Multimodal warnings incorporate audio and/or skin-based (tactile) cues to supplement or replace visual cues in environments where the user’s visual perception is busy, impaired, or nonexistent. This paper describes characteristics of audio, tactile, and multimodal warning displays and their role in risk communications. The authors demonstrate that visual–auditory and visual–tactile displays can be significantly more effective than visual displays alone in enhancing user performance. The authors describe signal design guidelines, and illustrate the importance of knowledge of user attentional constraints and limitations in effectively using multimodal displays to communicate safety information. Finally, conclusions and recommendations for future multimodal warning display design and research are presented.