Update index.html

index.html

@@ -1167,6 +1167,8 @@ document.addEventListener('DOMContentLoaded', function() {
             // 新しいaudio要素を作成
             combinedAudioElement = new Audio(url);
             combinedAudioElement.preservesPitch = true;
+            combinedAudioElement.mozPreservesPitch = true;
+            combinedAudioElement.webkitPreservesPitch = true;
             combinedAudioElement.playbackRate = currentPlaybackRate;
 
             isAudioCombined = true;