The directionality of an audio source is fundamental to navigation within an explorable, 3D audio game. With that in mind, it’s important to remind ourselves of how humans hear-
‘Directional information can be picked up because we have two ears, and each ear a complex, direction dependent filter (the pinna). This allows sensitivity to the timing differences and spectral shifts that specify direction. The pattern of radiant and reflecting sound can further aid localisation. Moreover, the auditory system is mobile. We can turn our heads to pick up shifting inter-aural patterns and to orient towards a sound, further improving localisation.’ (Gaver, 1993)
So now that’s established how do you make game mechanics from it?
Here are a few ideas-
⦁ Move Precision Required
A smaller entry point into a building, for example, requires more precision than a larger point. This can be implemented by having very generalised targets early on, with an ever increasing accuracy required later.
⦁ Object Occlusion
With moving objects in a scene changing occlusion adds increased difficulty as sources are becoming occluded.
⦁ Reverberant Spaces
A more reverberant environment makes a source more difficult to position. With this in mind one can increase difficulty by increasing the proposed size of the room, reducing its navigability. In technical terms, this means that the direct sound/reflected sound ratio low.
⦁ Soundscape Busy-ness
The more sounds in an area the more difficult it will be for the player to locate their intended location. A desert like soundscape with few sources will be far easier to navigate than a city at midday. Because of this auditory busy-ness one has to rely somewhat on the Cocktail Party Effect (see: En.wikipedia.org).
A final thought should go to what abilities the player may get to aid their navigation throughout the sound world, these are our ideas so far.
⦁ ‘Zoom’ Mechanic
Allows the player to ‘zoom’ from 0 to a set distance forwards, imagine an ‘auditory scope’.
⦁ Right or Left ‘Sonar’ Mechanic
Useful in small corridors, plays a bleep to the right/left, increasing/decreasing relative to the distance of the wall.
⦁ Leaving Auditory Signal Cues
Allows the player to sonically mark where they have previously been so that they don’t go back on themselves.
