The detection of target messages in a background of competing speech and the identification of the color/number combinations in those messages were examined in a continuous monitoring task. Previous research has shown that if listeners know when and where to listen, speech-on-speech intelligibility is improved when signals are presented via a 3-D audio display as compared with a diotic display. However, the effect of display type on detection of infrequent target messages in a continuous monitoring task has not been examined. Participants were required to monitor five communications channels conveying messages at random intervals under each of three audio display conditions: diotic, all channels in front, and channels separated in azimuth (3-D). Message detection sensitivity was significantly higher for the 3-D condition than for the in-front condition but did not differ significantly between the in-front and the diotic conditions. There were no differences in response criteria across conditions. Color/number identification sensitivity also was significantly higher for the 3-D condition than for the in-front condition but did not differ significantly between the in-front and the diotic conditions. A 3-D audio display enhances both message detection and message identification in a continuous monitoring task. Three-dimensional audio displays would be particularly beneficial in environments such as aviation, in which the information conveyed to operators via the auditory modality can be crucial to the safe and effective performance of their work.