YouTube: How to present embed video with sound muted

The accepted answer was not working for me, I followed this tutorial instead with success.

Basically:

<div id="muteYouTubeVideoPlayer"></div>
<script async src="https://www.youtube.com/iframe_api"></script>
<script>
 function onYouTubeIframeAPIReady() {
  var player;
  player = new YT.Player('muteYouTubeVideoPlayer', {
    videoId: 'YOUR_VIDEO_ID', // YouTube Video ID
    width: 560,               // Player width (in px)
    height: 316,              // Player height (in px)
    playerVars: {
      autoplay: 1,        // Auto-play the video on load
      controls: 1,        // Show pause/play buttons in player
      showinfo: 0,        // Hide the video title
      modestbranding: 1,  // Hide the Youtube Logo
      loop: 1,            // Run the video in a loop
      fs: 0,              // Hide the full screen button
      cc_load_policy: 0, // Hide closed captions
      iv_load_policy: 3,  // Hide the Video Annotations
      autohide: 0         // Hide video controls when playing
    },
    events: {
      onReady: function(e) {
        e.target.mute();
      }
    }
  });
 }

 // Written by @labnol 
</script>

For me works using &autoplay=1&mute=1

Updated

Add &mute=1 to the end of your url.

Your new code would be:

<iframe src="https://www.youtube.com/embed/uNRGWVJ10gQ?rel=0&amp;autoplay=1&mute=1" width="560" height="315" frameborder="0" allowfullscreen></iframe>