If the audio you hear from the video is always from a Youtube video, check your liked videos and watch history on Youtube to see if you have any weird videos that you didn't like or watch in there. If so, you might be experiencing this issue.
Your browser does not seem to support JavaScript. As a result, your viewing experience will be diminished, and you have been placed in read-only mode.
Please download a browser that supports JavaScript, or enable it if it's disabled (i.e. NoScript).