How close laterally should auditory cue be toward visual target to facilitate visual search under workload condition?

Abstract

Auditory cues can draw individuals’ spatial attention to visual targets and it enables individuals to find visual targets quickly. Some previous studies suggested that auditory cues should be in approximately the same functional field with visual targets (i.e., both events are presented within near field) to obtain quick responses even if in real situations such as driving. However, quantitative angular differences between auditory cues and visual targets are little investigated. This present study aimed to explore the angular differences that can elicit similar responses with auditory cues and visual targets presented from similar directions under workload conditions. Twenty-two participants were asked to perform visual search and tracking tasks simultaneously. The visual targets were at ±20°, ±40°, and ±60° in azimuth as 0° of frontal view with distance of 1.0 m from participants. The auditory cues were presented simultaneously with visual targets from 0°, ±20°, ±40°, and ±60°. The results of the response time analysis using a fitting approach revealed that the auditory cues within 40° from the visual targets could elicit similar responses similar with those when the auditory cues and visual targets were presented from the same direction even if the participants were deprived of their attentional resources by other tasks. When the angular difference between auditory cues and visual targets were larger than 60°, the participants’ spatial attention was drawn to directions different from visual targets. It elicited a delay in finding visual targets because the participants should reallocate their spatial attention to visual targets. These results have meaningful implications for audio-visual user interface designs.