Doesn't that require the same kind of trust in the correctness of the wiring that is at issue in some other comments? I can see that a camera cover works, but I think I couldn't see that a physical switch was actually interrupting the wiring without doing a teardown.
If you don't assume the internal wiring is as described I do not think there is a way for you to guarantee the microphone is not recording. It's even less obvious than a camera lens being covered or not, and taping over the "microphone hole" won't actually block receiving sound at all.
I do physically disconnect or cover cameras. My desktop computer has no microphone unless I plug one in. Laptop and phone though? I definitely remember in the aughts that the police could remotely turn your phone into a bug without any user indication at all. To the best of my knowledge the only way to actually be sure you aren't being recorded with your own equipment is to remove power... of course now the batteries are soldered on, totally a coincidence I'm sure.
Boy, wait until you find about what's possible manipulating PCB or processor designs (the Bloomberg fiction piece "The big Hack" illustrates what would be possible with just PCB manipulation). Or firmware or anything else proprietary running with elevated rights (normal ones are already enough to cause a lot of damage on most systems).
Well, what got it declared fiction was "a broad search doesn't turn up good evidence that this has been done", rather than "experts agree this is obviously impossible". So the reaction to the piece did demonstrate something.
Well, I don't mean to fuel your paranoia, but there are materials opaque to the human eye but not necessarily fully opaque to a CMOS sensor, especially one without infrared/UV filters.
It would be quite possible, trivial even, to design a web camera with a nice built-in black camera cover -- which is transparent to the camera.
