Do other things on your device make sound? First, verify that your device is making sound in some other way to verify that the problem is related to the live video itself. Common ways to do this might include increasing or decreasing your volume (some devices beep when you do this) or playing song. The Live Video has its own volume control. Is this muted? Hover over, or tap, the video. The control bar should appear at the bottom. In some devices/browsers, online videos will automatically start while muted.