[header] How to avoid screamers on youtube [title] Check the comments on the video before playing it. [step] Unless the user who uploaded the video disabled commenting, you will often quickly find out if the video is prankster's work by reading the irritated responses. Disabled commenting itself might also be a clue, as is a large number of " dislike " votes. 
[title] Some clues might alert you to screamers. [step] Clumsier ones ask you to turn up the volume on the speakers for some reason, or no reason at all.