Auditory tracking of multiple naturalistic moving objects

Thirty participants tracked auditorily moving sound sources to estimate the capacity for multiple identity tracking by hearing. The participants sat blindfolded in a gym hall. Four assistants moved about semi-randomly in a circular area around the participant and constantly repeated a proper name. Two to four of the assistants were designated as the targets. The participants were to keep track of the designated targets during the 10-sec movement phase. After the movement stopped, one target was probed and the participant provided the name of the probed target. Auditory tracking capacity was estimated to be 1.5 items, which is half the size of the visual tracking capacity. It is suggested that the limited capacity for auditory tracking is related to the difficulty in refreshing what-where -bindings in the auditory modality.