Thanks for the info. What is odd is I never went to these locations to change the typing sound and yet it wasn't originally on, and then it was on, and then it was off again. When I went to the locations you both mentioned, it said the sound was on....but....as I type now the only sound is the sound of my fingers typing, not the clicking sound. There must be a shortcut on the keyboard that I accidently triggered and that turned the sound on and then back off again....or....this is just one of those nutty little issues. The only thing I did was connect the keyboard to the SP2 (I use the Bluetooth adapter most of the time as I have the SP2 in a docking station) and once I did that, no more clicking sounds. Not a big deal, but now just curious as to what triggered it on and off.
Have no idea if it has anything to do with what you've described, but quite a number of times the system sound settings change without my deliberate action to change it.
Normally sound is muted on my SP2. My personal weirdness: I dislike machines talking, beeping or clattering at me. Please, I say, there's already enough noise in the world, I don't need more. Besides, there's seldom any additional information in it. Yes I can see that huge banner warning me the battery is getting low, adding noise is redundant.
But for reasons unknown, all of sudden the sound blares or bellows, sure enough the "mute" setting has been cancelled. Of course, I reset mute to "on", and peace and quiet is restored, but sure enough within a day or two it happens again.
The upshot of my rant is that you should check sound settings: apparently they can change through some spooky, self-willed and unpredictable mechanism afflicting the SP2.
As an aside, the sound drivers were found to be somehow affecting cold boot and CPU misbehavior. I'm beginning to wonder if the sound drivers are implicated in widespread, if unintended, effects on other SP2 subsystems in non-obvious ways. I'm very glad I'm not responsible for debugging such problems. They are the stuff of nightmares.