Tak jo, tak sis rejpnul a pak poradil blbě.
<html>
<body onload="playOnce()">
<script>
function playOnce() {
if (sessionStorage.alreadyPlayed) return;
document.getElementById("audio").play();
sessionStorage.alreadyPlayed = true;
}
</script>
<audio>
<source src="www.wolfcountry.net/mp3/WOLFHOWL1.mp3" type="audio/ogg"></source>
<source src="www.wolfcountry.net/mp3/WOLFHOWL1.mp3" type="audio/mpeg"></source>
Your browser does not support the audio element.
</audio>
</body>
</html>