Binaural Capture and Synthesis of Ambient Soundscapes

Phase II work is proposed to complete the design of and fabricate a marketable version of a fully-functional Phase I prototype system for binaural soundscape capture and synthesis. The Phase I system (see AFRL/ARL contract FA8650-08-M-6903) meets design specifications for portability (22 lbs for the capture system and 10 lbs for the playback system) and dynamic range (from threshold-of-hearing to above 110 dB SPL), while permitting natural 360º azimuth-plane head-rotation within the synthesized soundscape. The Phase II work plan will investigate the addition of head-pitch tracking and enhancement of azimuth-plane spectral cues with the goal of improving elevation localization and high-frequency source-on-source masking behavior.  It will also explore the possible use of less costly head-tracking technologies. Based upon evaluations of these modifications, the final system will be designed and fabricated, with special attention paid to weatherization and ruggedization.  A complete suite of accompanying software tools will also be developed and an initial database of soundscape recordings will be recorded.  The resulting hardware, software, and soundscape database will be packaged into two initial products: (1) a system intended to facilitate assessment of and training for target detection capability in the military and (2) a system intended to improve hearing aid fitting. BENEFIT: The capability to study the impact of a particular soundscape upon a listeners ability to operate effectively within the environment (e.g., target detection ability). The means to create a soundscape database whose individual components may be combined and manipulated to synthesize more complex soundscapes.  This will enable the study of the effect of individual soundscape elements upon human listeners.   The development of coping strategies designed to improve listeners functionality in a given soundscape (e.g., hearing-aid speech intelligibility in noise and general comfort). The creation of more realistic virtual audio environments that provide a richer sense of acoustic immersion for both military/industrial (training) and recreational (movie and video game) uses. Improved insight into soundscape composition and dynamics that will contribute to the creation of statistical soundscape models and will foster a greater understanding of inhabitant behavior and interaction in a given soundscape.