Attending visual and auditory signals : Ergonomics recommendations with consideration of signal modality and spatial stimulus-response (S-R) compatibility

This study investigated spatial stimulus-response (S-R) compatibility effects in a combined auditory-visual setting, in which subjects had to respond to a single signal that could be visual or auditory. Auditory signals were positioned either to the left or right of the subject on a transverse axis, and visual signals were positioned at two vertical locations in front of the subject on a longitudinal axis. There were three main findings. First, a strong spatial S-R compatibility effect was observed for both signal modalities and such correspondence of S-R positions elicited relatively faster responses. However, in a condition when either the visual or the auditory pairing was incompatible, reaction times increased dramatically. Second, responses made to the visual signals were generally faster than those to the auditory signals. This contradicted the previous finding that simple visual reaction time was longer than simple auditory reaction time. Thus, simple reaction times cannot be applied directly for the estimation of response speeds of different signal modalities in a multi-sensory control console. Third, a superior visual strength effect was observed in this choice reaction task. This visual strength effect was more marked in the conditions with conflicting S-R mapping pairings. Relevance to industry: This study showed that spatial S-R compatibility and signal modality are two important interface design factors for enhancing response efficiency of operators in a multi-sensory control console. Some ergonomics recommendations based on these findings are given with the aim of improving interface design in multi-sensory control consoles in order to enhance the operators' response speed and accuracy and overall system performance. © 2007 Elsevier B.V. All rights reserved.