trying to figure out why mob footsteps always sound nearby

mods/mobs/boar.lua

@@ -2,7 +2,9 @@
 -- Warthog(Boar) by KrupnoPavel
 -- Changed to Boar and tweaked by Kaadmy
 
-mobs:register_mob("mobs:boar", {
+mobs:register_mob(
+   "mobs:boar",
+   {
       type = "animal",
       passive = false,
       attack_type = "dogfight",
@@ -20,6 +22,7 @@ mobs:register_mob("mobs:boar", {
       sounds = {
 	 random = "mobs_boar",
 	 attack = "mobs_boar_angry",
+	 distance = 16,
       },
       walk_velocity = 2,
       run_velocity = 3,
@@ -46,7 +49,7 @@ mobs:register_mob("mobs:boar", {
 			 mobs:feed_tame(self, clicker, 8, true)
 			 mobs:capture_mob(self, clicker, 0, 5, 40, false, nil)
 		      end,
-})
+   })
 
 mobs:register_spawn("mobs:boar", {"default:dirt_with_grass"}, 20, 10, 15000, 1, 31000)
 mobs:register_egg("mobs:boar", "Boar", "mobs_boar_inventory.png")

mods/mobs/mineturtle.lua

@@ -6,7 +6,6 @@ mobs:register_mob(
       type = "monster",
       passive = false,
       attack_type = "explode",
-      damage = 2,
       hp_min = 10,
       hp_max = 15,
       armor = 200,
@@ -20,6 +19,7 @@ mobs:register_mob(
       sounds = {
 	 random = "mobs_mineturtle",
 	 explode= "tnt_explode",
+	 distance = 16,
       },
       walk_velocity = 2,
       run_velocity = 4,

mods/mobs/sheep.lua

@@ -20,6 +20,7 @@ mobs:register_mob(
       makes_footstep_sound = true,
       sounds = {
 	 random = "mobs_sheep",
+	 distance = 16,
       },
       walk_velocity = 1,
       walk_chance = 150,