A top-down yard with eight sound sources. Press Play sound, put on headphones and walk around: Today plays them the way the game handles them now, Planned the way this spec proposes. Drag yourself (the green character) to move; click anywhere else to face that way. With the yard selected, W A S D walks and Q E turns. The gold lines are sound reaching you: thicker is louder, dashed means a wall, glass or fence is in the way. Click a source in the list to see its range rings.

In Today, listen for

Your own mower sits half in your head: walk and turn, it barely moves.
The client on the porch goes silent past 18 m; your brother's mower stops dead at 45 m.
Walk into the house: the dog and the car get muffled, but your brother's mower and the sprinkler come straight through the wall.

In Planned, listen for

Turn around: your engine moves from in front of you to behind you.
Step inside: the mowers go dull and seem to come from the open door; the radio fills the room with a little echo.
Mow near the fence: the baby's room next door crosses the quiet-hours limit.