Осторожно, Раммштайн
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
Минуты: <input type="text" id="min" value="0">
Секунды: <input type="text" id="sec" value="5">
<button onclick="timer();">Старт</button>
<div id="time"></div>
<audio id='mySound' src='http://delaytesami.com/ramshtajn.mp3'/>
<script>
function timer(){
var min = document.getElementById('min');
var sec = document.getElementById('sec');
var div = document.getElementById('time');
var times = +sec.value + (+min.value * 60);
var intervalID = setInterval(function(){
div.innerHTML = times--;
if(times < 0 ){
PlaySound();
clearInterval(intervalID);
}
}, 1000);
}
function PlaySound() {
var mysound=document.getElementById('mySound');
mysound.play();
}
</script>
</body>
</html>