Try to plumb the other half

OpenSim/Framework/LandUpdateArgs.cs

@@ -56,5 +56,8 @@ namespace OpenSim.Framework
         public bool MediaLoop;
         public bool ObscureMusic;
         public bool ObscureMedia;
+        public bool SeeAVs;
+        public bool AnyAVSounds;
+        public bool GroupAVSounds;
     }
 }

OpenSim/Region/CoreModules/World/Land/LandManagementModule.cs

@@ -1553,6 +1553,19 @@ namespace OpenSim.Region.CoreModules.World.Land
             land_update.ObscureMusic = properties.ObscureMusic;
             land_update.ObscureMedia = properties.ObscureMedia;
 
+            if (args.ContainsKey("SeeAVs"))
+            {
+                land_update.SeeAVs = args["SeeAVs"].AsBoolean();
+                land_update.AnyAVSounds = args["AnyAVSounds"].AsBoolean();
+                land_update.GroupAVSounds = args["GroupAVSounds"].AsBoolean();
+            }
+            else
+            {
+                land_update.SeeAVs = true;
+                land_update.AnyAVSounds = true;
+                land_update.GroupAVSounds = true;
+            }
+
             ILandObject land;
             lock (m_landList)
             {

OpenSim/Region/CoreModules/World/Land/LandObject.cs

@@ -292,6 +292,9 @@ namespace OpenSim.Region.CoreModules.World.Land
                         ParcelFlags.AllowAPrimitiveEntry |
                         ParcelFlags.AllowGroupObjectEntry |
                         ParcelFlags.AllowFly);
+                newData.SeeAVs = args.SeeAVs;
+                newData.AnyAVSounds = args.AnyAVSounds;
+                newData.GroupAVSounds = args.GroupAVSounds;
             }
 
             if (m_scene.Permissions.CanEditParcelProperties(remote_client.AgentId, this, GroupPowers.LandSetSale, true))