INTRODUCTION Researchers (Furness, 1986; Stinnett, 1989) have recognized the tremendous potential that helmet-mounted displays (HMDs) and other virtual environment (VE) technologies have for enhancing pilot effectiveness in future air combat environments. However, in spite of the potential benefits, HMDs continue to be challenged by several technological limitations, including narrow fields of view (FOV), excessive helmet weight and bulkiness, display lag, inaccuracies in head position and tracking technologies, and suboptimal display resolution (see Beal & Sweetman, 1994, for review). Indeed, such limitations may potentially disrupt the highly coordinated perceptual-motor skills required to pilot modern tactical aircraft, thereby jeopardizing performance efficiency and pilot safety. Accordingly, we believe it is imperative to conduct empirical evaluations of HMDs and other virtual environment technologies so as to determine their effects on human perception and performance. Along these lines, Hettinger, Nelson, and Haas (1996) compared visual target detection in an HMD with that in a conventional dome display. In terms of performance efficiency, the HMD was found to be significantly poorer than the dome display with regard to percentage of correct detections (HMD = 73.4%, dome display = 99.8%) and the amount of time required to make a correct detection (HMD = 49.5 s, dome display = 39.4 s). In addition, participants' ratings of workload and fatigue were significantly higher in the HMD than in the conventional dome display. One potential way to offset the problems reported by Hettinger et al. (1996) would be to provide operators with synthetic or virtual three-dimensional (3D) auditory information, thereby exploiting the human auditory system's ability to direct the attention of the operator to the spatial location of the target. Indeed, numerous investigators (Barfield, Cohen, & Rosenberg, 1997; Begault & Pittman, 1996; Bronkhorst, Veltman, & Breda, 1996; McKinley, Ericson, & D'Angelo, 1994; Perrott, Cisneros, McKinley, & D'Angelo, 1996; Perrott, Sadralodabai, & Saberi, 1991; Sorkin, Wightman, Kistler, & Elvers, 1989; Wenzel, 1992; Wightman & Kistler, 1989) have recognized the potential of spatialized auditory displays for directing one's attention and enhancing spatial awareness. Accordingly, spatially localized auditory interfaces may be particularly well suited for tasks that require pilots to locate objects (e.g., targets, threats, waypoints, etc.) using narrow FOV HMDs. Toward that end, the present investigation was designed to evaluate the effects of virtual localized auditory information on target detection performance and workload when using an HMD. METHOD Participants. The 10 participants (3 women and 7 men) were naive to the purpose of the experiment. Their ages ranged from 19 to 25 years with a mean of 21.5 years. A preexperimental screening for visual and auditory acuity ensured that all participants had 20/20 or corrected-to-20/20 binocular visual acuity and normal auditory functioning. Participants were paid $5/h for their participation. Experimental design. There were four visual conditions in the experiment: full FOV, mechanically limited (ML) FOV, software-limited (SL) FOV, and HMD. In addition, there were four auditory conditions: no auditory information (none), nonlocalized auditory information (NL), auditory information localized in azimuth and elevation (two-dimensional [2D]), and auditory information localized in azimuth, elevation, and range (3D). The visual conditions were combined factorially with the auditory conditions to provide 16 experimental conditions. Participants completed each combination of the 16 possible auditory and visual conditions with the constraint that a single visual condition was paired with all four auditory conditions during each experimental session. Apparatus. …
['W. Todd Nelson', 'Lawrence J. Hettinger', 'James A. Cunningham', 'Bart J. Brickman', 'Michael W. Haas', 'Richard L. McKinley']
Effects of Localized Auditory Information on Visual Target Detection Performance Using a Helmet-Mounted Display