Some iPad, even iPhone users complain that the sound on their device suddenly stopped working.  You might not get sound even after moving the SIDE SWITCH button on your iPad Device. This happens in case you have the SLIDE SWITCH set to control rotation lock. To fix this issue follow these four steps:
1. Double click the HOME button.
2. Tray with app icons will appear. Swipe the tray with your finger to the right.
3. Tap the sound icon in the far left corner of the tray. This will unmute the sound.
4. Tap the screen of the iPad to leave the tray and go back to apps.

4 Steps to Fix Sound on iPad

 

Here are most common reasons why people cannot hear some applications, but they can listen to a TV show, movie, music or a podcast:

Side Switch and Volume Buttons on iPad 41. There seem to be certain apps, or combination of apps, that disable sound. Try doing a system re-set. Press the Home button and the on-off button on top of the iPad at the same time and hold until you see the Apple logo appear. DISREGARD any interim screens that appear, including the welcome screen, and just wait until the apple logo appears. This will “re-set” the iPad, but no data or settings will be lost. This should restore sound.

2. You may be able to hear audio playback, such as music, podcasts, movies, and TV shows but NOT notifications, sound effects and some apps. The SIDE SWITCH might be set to SILENT. The solution is to un-mute the SIDE SWITCH button.

3. It may happen that you do not get sound even after moving the SIDE SWITCH button that is because in the mean time you have the SLIDE SWITCH set to control rotation lock. To turn it back to being SOUND control again go to Settings, to General > Use Side Switch to, then tap Mute. After you have done this, open the app you wish to play and switch SLIDE SWITCH to un-mute.

 

In case you still need help with the sound please follow one of the links below:

1. iPad Sound Issue When Buttons Do not Help – Quick Fix:

2. iPad 2 Sound Issue – Quick Fix:

HOWEVER if you have an updated operating system on your iPad, if it is iOS 7 and above, you should know that on iOS7 the Control Center, where the mute button is switched to ON/OFF, is activated differently than on previous versions. Follow this link to deal with sound issues on iOS7:  iOS7 Sound Issue – Quick Fix in Control CenterThe following video will help you to solve the sound problem on later version of iOS (iOS7 and iOS8):