class Ambient, class Sounds, and your config?

[oktyabr 12]

I am really, REALLY hoping someone out there has figured out how ambient/ sounds work in config.cpp!

I see this one a lot but it's never (apparently) used or defined:

class Sounds
{
sounds[]={};
};

My particular situation is my tiny island that has a pretty significant swamp on one side of it. Even if just sounds are out of the question the "class ambient" section should allow the animals that make the sounds. This is the default:

class Ambient {
/*
         Layer cost and species probability use expressions.
         Variables which can be used inside of expressions:
       rain: rain intensity.
       night: 1 during night, 0 during day.

       hills: 0 at 150 ASL, 1 at 400 ASL.
       windy: 0 at 0 m/s, 1 at 20 m/s.

       trees: tree density.
       sea: distance to sea.
       houses: house density.
       meadow: meadow character.
       forest: 1 in the forest.

     Any values are continuous/interpolated in the range of 0 to 1.
     Values they are independent unless notes otherwise
     (meaning meadow and forest can be 1 at the same time).

     You can observe these values in real-time using:
         diag_toggle "ambient"
     */
class BigBirds {
radius = 300;
cost = "((1 + forest + trees) - ((2 * rain)) - houses) * (1 - night) * (1 - sea)";
....

Ok, so I think from above that there are pre-defined variables that decide what "house", "forest" and the like are. I think "forest" for example is decided by >X number of trees in a given grid section and "house" is likely any (or almost any) artificial object you can place on the map? "sea" is how many meters to the sea and "night" and "rain" should be pretty self explanatory. But how about "meadow"? And "trees"? Can one add custom variables to this list?

For example suppose I want to have heavy mosquitos in my swamp, especially at night. The only thing I can see provided the given variables is that my swamp is 'forest' but how do I keep a setting from then affecting all my forest area? On my specific island the big difference is that the swamp has an awful lot of mangrove bush objects in it. If this could somehow be tied, the presence of mangroves, to the ambient module then I would be in a sense defining my "swamp" as separate from "forest"?

It would be nice, and would make sense too, if you could use pre-defined keypoints as triggers for the ambient module.

I've googled the hell out of this one and searched the forums with about every combination of clever words I could think of and no where can I seem to find a guide or anything on how to actually make use of the ambient module or perhaps more importantly "class Sounds []"?

Help?!?!?!