You can make use of the HTML5 <audio>
tag: http://jsfiddle.net/STTnr/.
var audio = document.getElementById('audio');
setTimeout(function() {
audio.play(); // play it through JavaScript after 3 seconds
}, 3000);
HTML:
<audio src="something" id="audio"></audio>
Just hide the element itself:
#audio {
display: none;
}
Do note that no browser supports all formats. This can be frustrating, but you can supply your audio in several formats.