Add audio feedback to actions and affordances #3

Summary
The lack of audio feedback is noticeable in the app. I'm used to VR apps providing sound effects when there are actions or events. For example, when I hover over clickable objects, there should be a subtle sound effect to reinforce that the object is clickable.
Experimenting with audio feedback during debugging playback may also be interesting. There are a lot of visual animations that could be accompanied by audio cues (if the audio is well designed).

Platform (Vive, Rift, Windows MR, GearVR): Vive