Index: wp-includes/post.php
===================================================================
--- wp-includes/post.php	(revision 16407)
+++ wp-includes/post.php	(working copy)
@@ -5252,7 +5252,8 @@
 		'image'   => _x( 'Image',   'Post format' ),
 		'quote'   => _x( 'Quote',   'Post format' ),
 		'status'  => _x( 'Status',  'Post format' ),
-		'video'   => _x( 'Video',   'Post format' )
+		'video'   => _x( 'Video',   'Post format' ),
+		'audio'   => _x( 'Audio',   'Post format' ),
 	);
 	return $strings;
 }