Have you got notifications muted ? Only notifications (including games) get muted, so the Music/iPod and Videos apps, and headphones, still get sound.
Depending on what you've got Settings > General > Use Side Switch To set to (mute or rotation lock), then you can mute notifications by the switch on the right hand side of the iPad, or via the taskbar : double-click the home button; slide from the left; and it's the icon far left; press home again to exit the taskbar. The function that isn't on the side switch is set via the taskbar instead : http://support.apple.com/kb/HT4085
THANK YOU KING_PENQUIN IN UK, YOU HAVE ANSWERED MY QUESTION. HOW NEAT IS THAT? 2 TAPS ON THE HOME BUTTON, AND SWIPE THE TASKBAR, AND VIOLA, THERE IT IS, THE SOUND ICON AND I UNMUTED IT THERE.
THANK YOU SO MUCH FOR YOUR FAST ANSWER, I REALLY APPRECIATE YOU. I NEVER FOUND THAT INFO IN THE IPAD MANUAL. THANKS AGAIN,
IAMFRADA, KESWICK, ONTARIO, CANADA