From: Laukosargas Svarog
My proposal is for a per object override, not a global volume adjustment which would make quiet sounds inaudible.
I understand the problem, Lauk, but honestly I'm not sure this is the best solution.
One quick question and then my general feelings: Does "Restrict Spatialized Sound to this Parcel" help. Just curious since I still don't know for sure what it does.

Does it restrict sound coming in to your parcel, going out of your parcel, or both?
Anyway, sound is problematic in general and already has so many customizable features that it's impossible to know what people are going to hear when they come onto your land.
I was excited about sound initially but got disillusioned pretty fast. The WIKI is very clear about sound volume, but my experience of sound didn't correlate with what the WIKI says. When I first started using sound, it didn't seem to be nearly as loud as the WIKI states. Probably, this is because my sound settings. But I set the sound so that I could hear it, ignoring the WIKI. Then, of course, I got a complaint.

So I took down the sound and haven't taken the time to work with sound since.
But allowing sound to be configured with even more flexibility will just compound the problem.
I think we need better documentation about how to configure sound and a greater awareness about what a "standard" configuration should be. The only way that sound will be pervasive and useful is if everybody hears things similarly.
So, back to your problem. If a neighbor's sound is too loud, then I think you have to engage the neighbor and take the time to understand what the differences are in your sound configurations. It's difficult for the sound provider to know how other people are perceiving their sounds. Also, I wouldn't take it for granted that other people hear your sounds the way that you intend. If you follow the WIKI, then there's a good chance that I can't hear them the way that my sound is currently configured.
I think neighbors have got to collaborate on these things and also that it'd be helpful for land owners to provide a notecard that describes the "optimal" sound settings for their land and maybe have a place with a notecard that describes the sounds that should be heard there. It could make it easier for people to determine if their sound is configured correctly.