Human Research and Engineering Directorate Research Areas

Spatial Auditory Displays

Advisor: Letowski, Tomasz R (tom.letowski@us.army.mil 410.278.5864)
Aberdeen Proving Ground, MD

Keywords: Situation awareness; Auditory spatial orientation; Auditory localization; Auditory distance estimation;

The human auditory system provides information about acoustic environment and the identity and location of acoustic sources in space. An auditory (audio) display is a communication device providing information that is intended to be heard by the user. The information may have natural acoustic origin or can be acoustic representation (auralization) of non-acoustic information. Practical applications of auditory displays range from the generation of audible warning signals, through auralization of video images, to the generation of virtual environments for training purposes. Modern signal processing techniques have made it possible to capitalize on the ear’s unique spatial capabilities for transmitting through earphones or bone conduction interface a wide range of spatially oriented information from navigation guidance to simultaneous multi-channel communications in the whole 360o spherical angle. In order to take advantage of these capabilities, we need to understand the mechanisms by which the human ear detects, identifies, and localizes sounds under various operational conditions. We are studying the perception of sonic events in natural and virtual three-dimensional auditory space, focusing on the details of the acoustic signal that result in the accurate externalization of sounds. In order to design effective auditory displays, our other main focus is on the design and evaluation of sounds that convey particular meaning. These studies have both the basic and applied character. Their ultimate goal is to develop easy to use spatial auditory displays for a variety of military and non-military applications.

References:
Abouchacra, K., Breitenbach, J., Mermagen, T., and Letowski, T. (2001). Binaural helmet: Speech recognition performance using spatial sound. Human Factors 43(4), 584-594.

MacDonald, J., Henry, P., and Letowski, T. (2006). Spatial audio through a bone conduction interface. International Journal of Audiology, 45:  595-599, 2006.

Abouchacra, K., Letowski, T., Koehnke, J., and Besing, J. (2009). Clinical application of the Synchronized Sentence Set (S3). Proceedings of the 16th ICSV. Cracow (Poland): INCE July 5-9.