World sounds are heard in a radius around the bot, not the view

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/DESIGN.md

@@ -178,12 +178,13 @@ above, including:
 - **Fewer, smaller messages.** Molds show only a small percentage, red when blocked or spoiled and gold when a casting waits for F; details are in the hover panel. Bars dropping, blocked molds and set castings no longer pop up cards or toasts. Fan heat is a red marker on the fan; melted tubes and machines get a short red label where they were. Status lines are one short sentence. The owner found the messages too large and too many.
 
 - **World sounds are local.** Sounds from the world (water sizzling on hot metal or lava, and
-  any other event with a place) fade with distance from the view and pan left or right; they go
-  silent one screen width off-screen. The owner heard a constant snapping that followed the bot
-  in an older world but not in a new one. It was the sizzle: in the owner's world, water that
-  had found its way down to hot basalt and granite (480-800°C, about 500 grains below the
-  surface) boiled about 48 times a minute, and every sizzle played at full volume.
-
+  any other event with a place) are heard around the bot, whatever the zoom: full volume within
+  24 grains, fading to silent at 96, panned left or right. The owner heard a constant snapping
+  that followed the bot in an older world but not in a new one. It was the sizzle: in the
+  owner's world, water that had found its way down to hot basalt and granite (480-800°C, about
+  500 grains below the surface) boiled about 48 times a minute, every one at full volume. The
+  first fix faded sounds with distance from the view; zoomed out they were still heard, so the
+  owner asked for a radius around the bot instead.
 - **The silo has pixel art in the pixel look**, drawn grain by grain like the rest of the world;
   the smooth look keeps the illustrated silo. The owner noticed it looked the same in both.