The use of audio cues in 3D entertainment is not new. However, it has not been widely applied in geospatial applications. IMM is one application in which aural cues can offer many benefits. Although it is not visualisation, aural cues just like visualisation aim to serve to the user a perception of the environment.
Aural cues have one major advantage over visualisation, in that they can convey to the user that which is not in the users field of view. That is to say that with aural cues users can localise objects that they cannot see. In confined spaces this can be a big advantage. Moreover, aural cues (e.g., reverb) can be used to present to users the occupancy of space.