VG_STATIC void ent_volume_call( world_instance *world, ent_call *call );
VG_STATIC void ent_audio_call( world_instance *world, ent_call *call );
VG_STATIC void ent_volume_call( world_instance *world, ent_call *call );
VG_STATIC void ent_audio_call( world_instance *world, ent_call *call );