If you lost sounds for keyboard clicks, games or other apps, and notifications, system sounds may have been muted.
System sounds can be muted and controlled two different ways. The screen lock rotation can be controlled in the same manner as well.
Settings>General>Use Side Switch to: Mute System sounds. If this option is selected, the switch on the side of the iPad above the volume rocker will mute system sounds.
If you choose Lock Screen Rotation, then the switch locks the screen. If the screen is locked, you will see a lock icon in the upper right corner next to the battery indicator gauge.
If you have the side switch set to lock screen rotation then the system sound control is in the control center. Swipe up from the bottom of the screen to get to control center . Tap on the bell icon and system sounds will return.
If you have the side switch set to mute system sounds, then the screen lock can be accessed in the same manner as described above.
This support article from Apple explains how the side switch works.
This did not work for me though. Any guidance? I have side key to lock rotation and control screen shows un muted. This all began for me when I originally downloaded OS 7.0. It has been hit and miss ever since.
Some times when I have had sound the sound is so poor I have to go to my iphone to listen to something. Spending time today to figure out the problem.
Thanks in advance