I'm so sorry to hear of your sound issue.

Can you please move the switch on the side of the ipad near the volume buttons, to verify that your sound isn't muted? This 'ringer' switch is almost always the fix for problems with sound. And even turning up the volume won't start the sound unless that ringer switch is in the un-muted position.

If that doesn't work, can you try closing all other apps that you have running? To do this, double click the home button and swipe the apps up to close them.

Also, if you open your 'control center', can you please click and verify that mute isn't turned on? To access control center, swipe your finger up from the bottom of the screen and then click the icon that looks like a bell.

Here's an article about how the ipad side switch works. It can control muting audio or locking screen rotation, and we have had other users that have inadvertently muted their audio with the switch:

http://support.apple.com/en-us/HT4085

Please let us know if any of these fixes the issue for you.