LowLatencyAudio plugin: Where to call unload function reffered to an audio file?

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jQuery

PhoneGap

I have used LowLatencyAudio plugin in phonegap build to play sound and which works fine . But, when I referred this which says, unload function must be used in order to unload an audio file from memory. Otherwise, you will cause memory leaks. Here is my working code snippet.

<script type="text/javascript" src="phonegap.js"></script>
<script type="text/javascript" src="PGLowLatencyAudio.js"></script>
<script type="text/javascript" src="main.js"></script>
<script>
var lla;
var url_start = 'sounds/startup.wav';
document.addEventListener("deviceready",onDeviceReady,false);
function onDeviceReady(){
   if( window.plugins && window.plugin.LowLatencyAudio)
     {
     lla  = window.plugins.LowLatencyAudio;
     lla.preloadAudio(url_start, url_start, 1, success, fail);
     }
}

function play_startup(){
 lla.play(url_start);
}
</script>

//From main.js
play_startup();

My QUESTION is where I need to call unload function ? Is there any other way to avoid momory leaks?

Thanks in Advance.