Human Research and Engineering Directorate Research Areas

Auditory Situation Awareness in Complex Acoustic Environments

Advisor: AA Scharine

Key words: sound localization, situation awareness, complex acoustics, sound recognition, reverberation, spatial perception, warnings, noise

The Army Research Laboratory is investigating the effects of complex acoustical environments on Soldier performance. Acoustic signals are often the first evidence of activity or a presence and it is the only type of information about surrounding environment that is available to the Soldier regardless of the time of the day and from all directions. Detection of acoustic signals and recognition of acoustic signatures and the directions they are coming from is critical in that it may mean the difference between life and death. Recently, a suite of research facilities designed explicitly for spatial auditory research has been developed by the Army Research Laboratory. This facility, known as the Environment for Auditory Research or EAR, contains facilities for virtual spatial audio, measurement of auditory spatial acuity, perception of moving sounds, and perception of auditory distance in both indoor and outdoor environments. These facilities are unique in their size, versatility and the acoustical standards they meet. The primary research goal is to describe and predict the effects of auditory features present in urban military operations on Soldier auditory awareness and to quantify these effects on performance. Auditory situation awareness is defined as the ability to detect, recognize and localize sound events. Urban acoustic environments include the effects of reverberation, direct and indirect sound pathways, background and impulse noise, movement, and mutual masking of multiple sound sources including self-made Soldier’s sounds.  Perception and high level mental processing of these events is also dependent on the Soldier’s mission, knowledge of the physical environment, and attentional workload.  This research addresses issues not traditionally considered separately in auditory research because the complexities of the military auditory environment demand it. Data obtained from this research form the basis for determining the effects of Soldier equipment and spatial situation on auditory performance and feed various models of Soldier performance.