The advantage of knowing where to listen.

This study examined the role of focused attention along the spatial (azimuthal) dimension in a highly uncertain multitalker listening situation. The task of the listener was to identify key words from a target talker in the presence of two other talkers simultaneously uttering similar sentences. When the listener had no a priori knowledge about target location, or which of the three sentences was the target sentence, performance was relatively poor-near the value expected simply from choosing to focus attention on only one of the three locations. When the target sentence was cued before the trial, but location was uncertain, performance improved significantly relative to the uncued case. When spatial location information was provided before the trial, performance improved significantly for both cued and uncued conditions. If the location of the target was certain, proportion correct identification performance was higher than 0.9 independent of whether the target was cued beforehand. In contrast to studies in which known versus unknown spatial locations were compared for relatively simple stimuli and tasks, the results of the current experiments suggest that the focus of attention along the spatial dimension can play a very significant role in solving the "cocktail party" problem.