after updating my iPad i have no sound

Do you get volume in any apps e.g. in Music and Videos but not in other apps and notifications ? If you do then have you got notifications muted ? 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 above the volume switch, 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

If you don't get sound in any apps then have you tried a soft-reset to see if you get sounds after the iPad has restarted ? Press and hold both the sleep and home buttons for about 10 to 15 seconds (ignore the red slider), after which the Apple logo should appear - you won't lose any content, it's the iPad equivalent of a reboot. If that doesn't fix it then do you get sound via headphones - if you do then you coul try inserting/removing headphones and see if the fixes it

I Have the same problem. A restart cures it but only for a few minutes