Do you mean clicking noises for the keyboard? If so, there are a couple of things to check. Yes, I know you said you checked "the obvious" but you didn't tell us what the obvious were. So, you get the whole list to check.
(1) Check to make sure you don't have the iPad muted. Depending on how you have it set up, you can either move other switch on the side or do the four-finger swipe up to reveal the multitask bar. Then, a swipe to the right (to reveal the control panel from the left) will bring up volume controls. Regardless, you are looking for the unmute symbol.
(2) Or, if it's just the keyboard missing the clicks, you may have turned them off in Settings? To check, go to your Settings app and press on the "Sounds" line. At the bottom of the right sound should be a line titled "Keyboard Clicks." Make sure it is ON.
Hopefully, one of those will do it for you. Good luck and let us know how you get on.
Marilyn