# Miscellaneous Here, some miscellaneous techniques and ideas are listed that don't easily fit to other categories but may be somewhat characteristic of 6DoF AAR. :!: This page is still a work in progress. :!: ## Props and level of realism In augmented reality, virtual items are superimposed on a real environment. However, if the environment is completely empty by nature -- no furniture, items on walls, anything -- that may pose a few challenges in Audio AR for narrative engagement and design: - there may be a lack of (visual and physical) stimuli for the user - it will be hard for the virtual acoustic world to attach to anything - an empty venue may seem unrealistic, even if it was its natural state, unless the emptiness is justified by the story However, filling the space with props may turn out to feel unrealistic, too, if the items don't belong to the real, present-day context. This could happen if historic items are brought in even if they matched the acoustic story world. One solution could be to make the environment look like it is being renovated with a mix of tools, boxes, ladders, etc lying around. Maybe a previous exhibition is being teared down, and stuff for the new one has already been carried in. These kind of limbo states are often narratively interesting, and the props could be used in the AAR story in many ways. For example - artefacts recreated by augmented sounds (a broken transistor radio starts to receive a historic station) - objects referred to in the narrative (a virtual character is packing moving boxes, and we can see some cardboard boxes) - objects used as symbolic set pieces (real cardboard boxes substitute as furniture in the virtual story world) ## Controlling dynamics and attenuation curves Even if aiming at an illusion of reality, it is impossible to reproduce the huge dynamic range of real-world sound levels throughout the audio chain. The sound level changes that we wouldn't pay any attention in real life may sound easily 'wrong' in the virtual environment with loud sounds feeling uncomfortable and quiet sounds too quiet. Because of that, it may be necessary to manually tweak distance-based attenuation (roll-of) curves to flatten the level differences. Also, sounds and dialogues with a great dynamic range, e.g. from whisper to shouting, might need manual or automatic level adjustments. ## Unification Using persistent sounds throughout scenes to bind them together.((Chion, Michel. //Audio-Vision: Sound on Screen//, Columbia University Press, 1994, p. 47)) For instance, a continuous background ambience can be used to unify scenes and enhance the experience of the space. In acoustically transparent AAR, however, additional ambiences must be used carefully to avoid sound clutter.