diff --git a/inc/parser/xhtml.php b/inc/parser/xhtml.php
index 263b0592f7cabccf5322d2746cd60ec022c8cdc6..44ead9d45c0c71a734f121bcad5f7418fd5479fe 100644
--- a/inc/parser/xhtml.php
+++ b/inc/parser/xhtml.php
@@ -1650,7 +1650,7 @@ class Doku_Renderer_xhtml extends Doku_Renderer {
 
         if ($isExternal) {
             // take direct source for external files
-            list($srcExt, $srcMime) = mimetype($src);
+            list(/*ext*/, $srcMime) = mimetype($src);
             $files[$srcMime] = $src;
         } else {
             // prepare alternative formats
@@ -1701,11 +1701,12 @@ class Doku_Renderer_xhtml extends Doku_Renderer {
      * @return string
      */
     function _audio($src, $atts = null) {
+        $files = array();
         $isExternal = media_isexternal($src);
 
         if ($isExternal) {
             // take direct source for external files
-            list($srcExt, $srcMime) = mimetype($src);
+            list(/*ext*/, $srcMime) = mimetype($src);
             $files[$srcMime] = $src;
         } else {
             // prepare alternative formats