Spatial attention in an auditory dual task

Abstract

Research on divided auditory attention has focused on the ability of listeners to report keywords from two spatially separated simultaneous talkers (Best et al., 2006); however, the information that listeners extract from each talker is the same (i.e., keyword identification). In realistic listening environments, there is often a competing demand for auditory attention; listeners might be required to monitor critical auditory events while also responding to an ongoing auditory signal. It is not clear how spatial separation affects performance in auditory dual-tasks under varying levels of task difficulty. Listeners identified an ongoing stream of color/number keywords originating at 0° azimuth (primary task), while detecting the presence of a critical call sign originating from locations ranging from −45° to + 45° (secondary task). The difficulty of the primary task was varied by introducing noise or by requiring stimuli identification in an auditory one- or two-back memory recall task. The difficulty of the secondary task was varied by increasing the set-size of critical call signs that listeners had to monitor and by changing the SNRs. Preliminary results indicate that a listener's ability to detect the presence of a critical call sign increased as its spatial location moved further away from 0° azimuth and performance was modulated bythe difficulty of the primary task. The result has important implications for spatial attention as a function of task difficulty in multitalker environments.