If keyboard clicks sound is bit annoying for you or due to any reason you want to turn the typing sound off then follow the given steps.
From iPad 2 home screen, tap Settings icon
Tap “General” from left-side and then tap “Sounds” on the right-side
Turn the “Keyboard Clicks” ON/OFF slider to OFF position, as show below.
Press the Home button to go back to home screen, now check by keyboard sound by typing in an app.