An Exploratory Study of the Use of Movement-Correlated Cues in an Auditory Head-Up Display

Abstract

An auditory head-up display (AHUD) can provide a pilot with information about target azimuth and elevation. The AHUD presents headphone stimuli whose apparent position is fixed relative to the cockpit and invariant with respect to head movement. In normal (movement-linked) operation the AHUD samples the head position and then corrects the headphone stimuli so that they are perceived to be at fixed positions in physical space. This experiment tested the ability of observers to localize targets with an AHUD under different movement conditions. After listening to a sequence of three signals, the observer had to indicate the target's location. Three different conditions relating the observer's head movement to the target's spatial position were tested: (a) target fixed in physical space (normal AHUD mode), (b) no head movement allowed, and (c) target fixed in position relative to the observer's head. Azimuthal localization was much better when the position of the stimulus was veridically correlated with head movement, demonstrating the contribution of visual, kinesthetic, and vestibular cues to sound localization.