The accepted answer works pretty good. I wanted more control so I added a couple of functions more to the script:
function unmuteVideo() {
player.unMute();
return false;
}
function muteVideo() {
player.mute();
return false;
}
function setVolumeVideo(volume) {
player.setVolume(volume);
return false;
}
And here is the HTML:
<br>
<button type="button" onclick="unmuteVideo();">Unmute Video</button>
<button type="button" onclick="muteVideo();">Mute Video</button>
<br>
<br>
<button type="button" onclick="setVolumeVideo(100);">Volume 100%</button>
<button type="button" onclick="setVolumeVideo(75);">Volume 75%</button>
<button type="button" onclick="setVolumeVideo(50);">Volume 50%</button>
<button type="button" onclick="setVolumeVideo(25);">Volume 25%</button>
Now you have more control of the sound... Check the reference URL for more: