Spatial sound [Anderson-Casey97] is modeled by many attributes. Directionalization can be modeled by binaural ITD (interaural time difference), IID (interaural intensity difference), and pinnae effects [Begault94]. Distance cues are based on delay, reverberation and loudness. The space, consisting out of objects interacting with sound waves, defines the reverberation and first- (and higher-) order reflections.
Important for this paper is the following definition:
A ``soundscape'' is a spatial region in which sound sources, sound sinks, and interactions between objects with sonic results can share common media, geometries, and spatial mappings. The media define such sonic features as the speed of sound within the soundscape, but can be extended to include sonic reflecting materials and reverberation attributes. The geometries and spatial mapping define how sound may be distributed for sophisticated and/or efficient audio rendering.