Effects of stimulus source and intensity on covert orientation to auditory stimuli.

Normal subjects showed costs and benefits of informative auditory spatial cues with auditory targets in RT tasks when stimulus intensity was low, or when the stimuli were presented monaurally through headphones. These findings imply that attention to auditory stimuli, like attention to visual or tactile stimuli, can be shifted spatially in detection tasks, and that covert orienting to auditory stimuli occurs in conditions favoring the intention to orient the head to a sound source. According to this view, orienting of attention to auditory stimuli, as well as to visual and tactile stimuli, is linked functionally to mechanisms controlling overt orienting movements that increase stimulus identification.