Use .ogg for the skeleton sounds after all (to save space).

data/campaigns/Heir_To_The_Throne/scenarios/14_Plunging_Into_the_Darkness.cfg

@@ -475,13 +475,13 @@
                     time=500
                 [/delay]
                 [sound]
-                    name=gryphon-shriek-2.ogg
+                    name=staff.wav
                 [/sound]
                 [delay]
                     time=200
                 [/delay]
                 [sound]
-                    name=skeleton-hit.wav
+                    name=gryphon-shriek-2.ogg
                 [/sound]
                 [delay]
                     time=200

data/campaigns/Liberty/units/Bone_Knight.cfg

@@ -24,7 +24,7 @@
     cost=35
     usage=scout
     unit_description= _ "Once great warriors across the plains, these mounted riders atop their skeletal horses were raised from the ground by unholy magic to spread fear and destruction."
-    get_hit_sound=skeleton-hit.wav
+    get_hit_sound=skeleton-hit-1.wav
     [defend]
         [frame]
             begin=-100

data/campaigns/Liberty/units/Death_Squire.cfg

@@ -19,7 +19,7 @@
     [/abilities]
     usage=fighter
     unit_description= _ "Sometimes the mightiest warriors and generals, cursed with hate and angst, came back to this world as Death Knights. Death Squires serve them whilst accruing enough unholy power to become Death Knights. In the process they pick up a good deal of the Knight's power, including the ability to command underlings."
-    get_hit_sound=skeleton-hit.wav
+    get_hit_sound=skeleton-hit-1.wav
     [defend]
         [frame]
             begin=-100

data/campaigns/Liberty/units/Skeleton_Rider.cfg

@@ -24,7 +24,7 @@
     cost=19
     usage=scout
     unit_description= _ "Once great warriors thundering across the plains, these mounted riders atop their skeletal horses were raised from the grave by unholy magic to spread fear and destruction."
-    get_hit_sound=skeleton-hit.wav
+    get_hit_sound=skeleton-hit-1.wav
     [defend]
         [frame]
             begin=-100

data/campaigns/Under_the_Burning_Suns/units/Undead_Horseman.cfg

@@ -11,7 +11,7 @@
             image="units/undead/skeletonrider-moving.png"
         [/frame]
     [/movement_anim]
-    {DEFENSE_ANIM "units/undead/skeletonrider-defend.png" units/undead/skeletonrider.png skeleton-hit.wav }
+    {DEFENSE_ANIM "units/undead/skeletonrider-defend.png" units/undead/skeletonrider.png {SOUND_LIST:SKELETON_HIT} }
     hitpoints=36
     movement_type=mounted
     movement=7
@@ -32,7 +32,7 @@
     cost=19
     usage=scout
     unit_description= _ "Once great warriors across the plains, these mounted riders atop their skeletal horses were raised from the sands by unholy magic to spread fear and destruction."
-    die_sound=skeleton-die.wav
+    die_sound={SOUND_LIST:SKELETON_DIE}
     [attack]
         name=axe
         description= _"axe"

data/core/macros/sound-utils.cfg

@@ -206,13 +206,13 @@
     orc-small-die-1.ogg,orc-small-die-2.ogg #enddef
 
 #define SOUND_LIST:SKELETON_HIT
-    skeleton-hit-1.wav,skeleton-hit-2.wav,skeleton-hit-3.wav #enddef
+    skeleton-hit-1.ogg,skeleton-hit-2.ogg,skeleton-hit-3.ogg #enddef
 
 #define SOUND_LIST:SKELETON_BIG_HIT
-    skeleton-big-hit-1.wav,skeleton-big-hit-2.wav,skeleton-big-hit-3.wav #enddef
+    skeleton-big-hit-1.ogg,skeleton-big-hit-2.ogg,skeleton-big-hit-3.ogg #enddef
 
 #define SOUND_LIST:SKELETON_DIE
-    skeleton-die-1.wav,skeleton-die-2.wav #enddef
+    skeleton-die-1.ogg,skeleton-die-2.ogg #enddef
 
 #define SOUND_LIST:TROLL_HIT
     troll-hit-1.wav,troll-hit-2.wav,troll-hit-3.wav,troll-hit-4.wav #enddef

data/core/units/monsters/Skeletal_Dragon.cfg

@@ -24,7 +24,7 @@
         arcane=100
     [/resistance]
     unit_description= _ "Long ago one of the mightiest living creatures, the feared Dragon has become only bones and dark sinew. Long after its death, it was raised through the dark powers of necromancy, which it now serves. The Skeletal Dragon may look like nothing more than a pile of bones, but few people who thought that way lived long enough to change their minds."
-    die_sound=skeleton-big-die.wav
+    die_sound=skeleton-big-die.ogg
     [attack]
         name=jaw
         description=_"jaw"

data/core/units/undead/Skele_Banebow.cfg

@@ -18,7 +18,7 @@
 
 Special Notes:"+{SPECIAL_NOTES_SUBMERGE}
     usage=archer
-    die_sound=skeleton-big-die.wav
+    die_sound=skeleton-big-die.ogg
     [abilities]
         {ABILITY_SUBMERGE}
     [/abilities]

data/core/units/undead/Skele_Bone_Shooter.cfg

@@ -17,7 +17,7 @@
 
 Special Notes:"+{SPECIAL_NOTES_SUBMERGE}
     usage=archer
-    die_sound=skeleton-big-die.wav
+    die_sound=skeleton-big-die.ogg
     [abilities]
         {ABILITY_SUBMERGE}
     [/abilities]

data/core/units/undead/Skele_Chocobone.cfg

@@ -20,7 +20,7 @@
     unit_description= _ "Riding the bones of ostrich-like large birds once used as mounts by a lost civilization, the skeletal Chocobones can move faster than most cavalry units.
 
 Special Notes:"+{SPECIAL_NOTES_SUBMERGE}
-    die_sound=wail-long.wav
+    die_sound={SOUND_LIST:SKELETON_DIE}
     {DEFENSE_ANIM "units/undead-skeletal/chocobone-defend.png" "units/undead-skeletal/chocobone.png" {SOUND_LIST:SKELETON_HIT} }
     [attack]
         name=spear

data/core/units/undead/Skele_Deathblade.cfg

@@ -18,7 +18,7 @@
     unit_description= _ "In life, the abominations known as 'Deathblades' were masters of combat, soldiers who were both lithe and deadly. Their new masters, recognizing this, outfit them to match the skills they once had. Though frail, these monsters are much faster than the rest of their kind, both on foot and with their blades.
 
 Special Notes:"+{SPECIAL_NOTES_SUBMERGE}
-    die_sound=skeleton-big-die.wav
+    die_sound=skeleton-big-die.ogg
     [abilities]
         {ABILITY_SUBMERGE}
     [/abilities]

data/core/units/undead/Skele_Draug.cfg

@@ -18,7 +18,7 @@
     unit_description= _ "There is little left, in these towering ruins, of the men they once were. Warriors at heart, they are now lost in the dream of unlife; wandering through the battles of their memory and fighting desperately for release, for a peace bought only by strength of arms. And so they struggle; both unthinking, and unrelenting.
 
 Special Notes:"+{SPECIAL_NOTES_SUBMERGE}
-    die_sound=skeleton-big-die.wav
+    die_sound=skeleton-big-die.ogg
     [abilities]
         {ABILITY_SUBMERGE}
     [/abilities]

data/core/units/undead/Skele_Revenant.cfg

@@ -17,7 +17,7 @@
     unit_description= _ "Given false life to do battle once more, the creatures known as Revenants were clearly great warriors in their time, though the memory of that time is now long gone. Even the sorcerers who raised them can only speculate on their past. Such questions aside, a Revenant is a powerful tool in combat: a fearless warrior that feels no pain, and which will fight to the bitter end.
 
 Special Notes:"+{SPECIAL_NOTES_SUBMERGE}
-    die_sound=skeleton-big-die.wav
+    die_sound=skeleton-big-die.ogg
     [abilities]
         {ABILITY_SUBMERGE}
     [/abilities]