HLS player sound is muffled when playbackRate is larger than 1.0
I don't know if this problem was occured before OS 13 version up of MacOS & Safari
Implementation is here...
```
<html>
<body>
<button onclick="getPlaySpeed()" type="button">What is the playback speed?</button>
<button onclick="setPlaySpeed()" type="button">Set video to be play in lapid motion</button><br>
<video id="myVideo" width="320" height="176" controls>
<source src="https://mnmedias.api.telequebec.tv/m3u8/29880.m3u8">
</video>
<script>
var vid = document.getElementById("myVideo");
function getPlaySpeed() {
alert(vid.playbackRate);
}
function setPlaySpeed() {
vid.playbackRate = 2.0;
}
</script>
</body>
</html>
```
Source file : https://mnmedias.api.telequebec.tv/m3u8/29880.m3u8
Safari verion: 13.0.2