Development and evaluation of auditory symbology for representation of simultaneous threats

This report describes the development and evaluation of auditory symbology for use in the Joint Advanced Strike Technology-Integrated Helmet Audio Visual System (JAST-IHAVS) program. The JAST-IHAVS program was a demonstration of an integrated visual helmet-mounted display (HMD) with advanced 3-D audio technology, headtracking, active noise reduction, and voice control for reduced pilot workload, enhanced target acquisition, and improved situation awareness. This effort developed and evaluated two sets of sixteen auditory symbols for representing four threat levels and four threat priorities. One set of auditory symbology was based on tones from a standard radar warning receiver (RWR) based on inputs from the IHAVS lead test pilot. The second set of auditory symbology was based on those developed in a previous research project at Georgia Tech. Each auditory symbology set was evaluated in a series of laboratory tasks for identifiability and localizability. Identification and localization tasks tested auditory symbologies presented alone and in combinations of up to four simultaneous threats. Overall, the auditory symbology based on the RWR tones was evaluated as satisfactory in terms of localization accuracy and identification of threat level. However, the auditory symbology based on RWR tones was unreliable and the perception of both threat and priority level was unreliable when heard in combination of two or more simultaneous threats. The second set of auditory symbology was evaluated as satisfactory on all counts.