Previous research has shown that speech-on-speech intelligibility is improved when signals are presented via a three-dimensional (3-D) audio display as compared with a diotic display if listeners know when and where to listen. Three-dimensional audio displays are particularly beneficial in environments such as aviation, in which the information conveyed to operators via the auditory modality can be crucial to safe and effective performance. Since the effect of display type on detection of infrequent target messages in a continuous monitoring task has not been studied previously, this study examines the detection of target messages in a background of competing speech and the identification of the color/number combinations in those messages in a continuous monitoring task. 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). Results showed that 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. 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. There were no differences in response criteria across conditions. These findings indicate that a 3-D audio display enhances both message detection and message identification in a continuous monitoring task.
Abstract