The volume cranked up to 11, of course, can ruin one's equipment and is guaranteed to disturb AND/OR disrupt others in adjacent classrooms or living units, so as a precaution there is a strict rule in place which states that the volume level must not be cranked up any higher than 5 1/2 when earphones are not being used.
[size=8pt]Beginner's mistake, scanman1. You have to bold ALL of your ending clue for it to count, which is why I incorporated the "of course" into my opening clue. I can be a lenient guy so I'm not going to issue demerits this time, although I'm sure Señors WMC, dmargalotti etc. will probably feel differently. I'll have a few words with them at the next staff meeting if they do.