var Earcons = (function() {
   // Earcons are like icons, but use symbolic sounds instead of pictures
 var trackUrls = [
 "audio/newpage.mp3", "audio/fgrow.mp3", "audio/fshrink.mp3",
 "audio/slideright.mp3", "audio/slideleft.mp3", "audio/sdiv.mp3", "audio/tell.mp3",
 "audio/office_lobby.mp3", "audio/footstep.mp3", "audio/apple.mp3",
 "audio/typewriter.mp3",
 "audio/walking.mp3", "audio/macspeak.mp3", "audio/picklock1.mp3",
 "audio/gossip.mp3", "audio/winenter.mp3", "audio/winleave.mp3", "audio/beep.mp3"];

 var trackTitles = [
 "soundOnLoad", "soundOnGrow", "soundOnShrink", "soundOnSlideRight",
 "soundOnSlideLeft", "soundOnDiv", "soundOnParagraph", "work",
 "soundOnList", "apple", "stype", "walk", "macbook",
 "soundOnLink", "soundOnInput", "winenter", "winleave", "soundOnImage"];

 var trackPtr = 0;

 var getTrackNumber = function (trackName) {
   for (i = 0; i < trackTitles.length; i++) {
     if (trackName == trackTitles[i]) return i;
   }
   return -1;
 };

 var preload = function() {
   if (trackPtr >= trackUrls.length)
   { trackPtr = 0; return; }
   var trackId = "st" + trackPtr + "";
   var trackUrl = trackUrls[trackPtr];
   trackPtr++;
   var soundTrack = soundManager.createSound ({stream: false,
   id: trackId,
   url: trackUrl,
   autoLoad: false, autoPlay: false});
   soundTrack.load ({onload: function() { preload(); } });
 };

 var unload = function() {
   for (i = 0; i < trackUrls.length; i++) {
     var soundTrack = soundManager.getSoundById ("st" + i);
     soundTrack.unload();
     soundTrack.destruct();
   }
 };

 interface = {
   trackUrls: trackUrls,
   trackTitles: trackTitles,
   getTrackNumber: getTrackNumber,
   preload: preload,
   unload: unload
 };


  return interface;

} )();

 var Narrations = (function() {
  var trackUrls = [
  "audio/about.mp3", "audio/webtech.mp3", "audio/screenreader.mp3",
 "audio/services.mp3", "audio/stories.mp3", "audio/settings.mp3",
  "audio/feedback.mp3", "audio/display.mp3", "audio/soundset.mp3",
  "audio/voiceset.mp3", "audio/divmain.mp3", "audio/divcenter.mp3",
 "audio/divnav.mp3"];

 var trackTitles = [
 "About This Web App", "Web Development Technologies", "What's A Screen Reader",
 "Services I Can Offer", "Stories, Poetry, Anecdotes", "Settings",
 "Send Me Your Comments", "Display Settings", "Sound Settings",
 "Voice Quality Settings", "div mainContent", "div center", "div navBar"];

 var trackPtr = 0;

 var getTrackNumber = function (trackName) {
   for (i = 0; i < trackTitles.length; i++) {
     if (trackName == trackTitles[i]) return i;
   }
   return -1;
 };

 var preload = function() {
   if (trackPtr >= trackUrls.length)
   { trackPtr = 0; return; }
   var trackId = "vt" + trackPtr + "";
   var trackUrl = trackUrls[trackPtr];
   trackPtr++;
   var voiceTrack = soundManager.createSound ({stream: false,
   id: trackId,
   url: trackUrl,
   autoLoad: false, autoPlay: false});
   voiceTrack.load ({onload: function() { preload(); } });
 };

 var unload = function() {
   for (i = 0; i < trackUrls.length; i++) {
     var voiceTrack = soundManager.getSoundById ("vt" + i);
     voiceTrack.unload();
     voiceTrack.destruct();
   }
 };


 interface = {
   trackUrls: trackUrls,
   trackTitles: trackTitles,
   getTrackNumber: getTrackNumber,
   preload: preload,
   unload: unload
 };

 return interface;
})();