Have you got notifications muted ? Only notifications (including games) get muted, so the iPod/Music 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
Assuming that I'm thinking of the correct icon, then the arrow that shows at the top of the screen indicates that an app is currently using location services. What are trying to achieve by tapping on it ?