Audio Zones

[keianhzo]

Is your feature request related to a problem? Please describe.
Hubs (or better said WebAudio API) doesn't support real life audio behaviors like audio occlusion and audio obstruction. This leads to certain situations where audio experience is confusing, for example, the scene might have different rooms and a user would expect the audio from one room to be attenuated by the walls and hardly audible when you are in another.

Alternative users could simply want to create certain "bubbles" where they want the audio to behave in a different way for artistic purposes.

Describe the solution you'd like
We need some way of defining audio zones where the AudioPanner node settings can be overridden for avatars outside that zone. For example refDistance con be set to a low value and rollOffFactor to a high one so the room audio is hardly audible outside that zone. Avatars inside that zone would experience the audio original settings but avatars outside would experience the overridden settings. This audio zones should be added in Spoke when designing the scene.

Additionally we could study implementing some basic audio occlusion/obstruction to attenuate audios that are obstructed by any other objects.

From the user experience perspective would be interesting to study if it would be interesting to provide any visual cue when avatars change audio zones, a text notification or some sort of translucent visual area that matches the audio zone shape.

Relate #1853