Sound level low

[kfarr]

Test user reports:

Sound level is really low. Wasn't really able to hear something until I turned the volume to the max.

Issue:

• Tram SFX is nonpositional but low (0.3)
• BG ambient audio is positional

Instead:

• Tram SFX should be higher but positional (testing needed)
• BG should be nonpositional but low

[kfarr]

Dev notes / changes:

• ambient audio changed to non positional and high volume (1); note the source audio is ambient so relatively low even at maximum volume (by design as an ambient audio clip)
• Tram SFX may be positional but it is hard to understand behavior. Writing that up now

[kfarr]

Wrote up this nifty little thing: https://medium.com/@kfarr/understanding-web-audio-api-positional-audio-distance-models-for-webxr-e77998afcdff