Pilots operating aircraft, such as helicopters and unmanned aerial vehicles, may benefit from a supplementary auditory display because they navigate in two dimensions while performing head-up, out-of-aircraft, visual tasks.

This study examined whether azimuth localising performance for non-individualised 3-D audio without integrated head tracking can be improved through the provision of supplementary reference signals. Twenty-two participants attempted to determine the location of spatial sounds developed through a non-individualised head-related transfer function (HRTF) while performing a visual distractor task. Localising sounds were randomly presented at 0-degrees elevation for each 10-degree increment about the azimuth. Three audio conditions were tested, two of which included different supplementary cues in the form of stationary and transient sounds that were spatially positioned to aid localising reference toward the midsagittal plane and interaural axis. The supplementary cues decreased errors in frontback perception; however, they did not significantly aid azimuth localising performance, and occasionally were reported to distract and disorient some participants. Supplementary audio cues have the potential to improve localising performance but should be more closely associated with the presented sound to lessen distraction and disorientation.

Modern aircraft are fitted with sophisticated technologies that support or fully automate tasks that were once performed solely by the pilot. This means that pilots now spend much of their time monitoring instruments and managing the automation rather than manually manipulating flight controls. While modern flight decks are extremely safe, pilots do occasionally experience high visual workload conditions that may degrade their ability to effectively monitor flight instruments. This thesis describes the design and evaluation of spatial auditory displays that are intended to improve a pilot's ability to monitor flight deck instruments under conditions of high visual workload. The aims broadly focus on developing design features that enable a pilot to perform head-up monitoring of an aircraft's navigation readouts while concurrently attending to verbal dialogue.