Auditory localization under spatial disorientation

Two tasks sharing common resource demands are time-shared less efficiently than two tasks with non-overlapping demands (Wickens, Sandry. & Vidulich, 1983). Thus, a possible method for improving operators' efficiency and performance in the visually demanding cockpit environment is to utilize percepmal systems other than vision for communicating important information like aircraft attimde (Forbes, 1946). Current advances in audio research provide a possible solution for alleviating the heavy workload currently imposed upon the visual system of the pilot. Auditory signals are currently used for many types of information for the aircraft pilot. Both two-dimensional and three-dimensional auditory cues are of particular interest because information can be processed by a pilot without the use of visual processing. The use of three-dimensional audio signals is particularly intriguing as it provides a means of providing spatial information in an auditory rather than visual modality. Thus, it would appear that the use of auditory cues for assisting spatial orientation in aircraft tasks could be very beneficial. Several investigations conducted thus far have explored the use of three-dimensional auditory information as an alternative or complementary addition to visual displays (Deartherage, 1972; Doll, Gerth, Fugleman & Folds, 1986, Endsley & Rosiles, 1995). A primary advantage of implementing three-dimensional auditory displays is that they assist listeners in monitoring and identifing sources of information from different locations, not just the direction of gaze (Wenzel. Wightman & Foster 1988). Funharmora, three-dimensional auditor} spatial information could be used to direct the pilots attention in locating critical events in the flight environment. Perrott, Sadralodabai, Saberi. and Strybel (1991) reported that three-dimensional aurally guided visual search for a target in a cluttered display is superior to unaided visual search, even for objects in the central visual field. Three-dimensional auditory technology increases information available to the pilot without requiring visual fixation by providing greater bandwidth than non localized auditory cues. When visual fixation is required, a directional sound can provide the listener with a more rapid cue as to where to aim his or her eyes or head (Jones & Kabanoff. 1975). Thus, auditory spatial cues, in conjunction with the other senses, can act as potentiators for information in a display. For instance, visual and auditory cues together can reinforce the information content of a display and provide a greater sense of presence or realism in a manner not readily achieved by either modality alone (O'Leary & Rhodes 1984; Warren, Welsh & McCarthy, 1981). This namral aural directional cueing should decrease the excess demands placed upon the visual modality, reduce display clutter, and also alleviate cognitive attention to process and extract meaning from coded formats (Doll, Gerth, Engleman & Folds, 1986).