Synchronous and asynchronous presentations of auditory and visual signals: Implications for control console design

In this study, the effects of synchronous and asynchronous auditory and visual signal presentation on reaction times and response errors were examined to provide data for developing ergonomics recommendations for control console design. The results showed that synchronous presentation for combined visual and auditory stimulation facilitated responses, and shorter reaction times and higher response accuracies were obtained. When visual and auditory stimuli were presented synchronously but in opposing (left and right) positions, a visual dominance phenomenon was found, such that the subjects responded more often (81%) with faster responses to the visual signal. This visual dominance effect occurred even in the asynchronous condition when the auditory stimulus was presented 200 ms earlier than the visual one. It was also found that response speed and accuracy improved with increasing length of the warning time interval, and when an uncrossed hand posture was used for making responses. The above results were translated into practical ergonomic recommendations for response key layout, warning time interval, and ways of presenting visual and auditory signals to improve control console design.