[hrkristian]

Better then, to have hardware switches similar to the iPhone lock switch.

I'd welcome that in general! Make the switch open up the camera app directly, and a similar one for the mics; binding it to your phone or recording app, depending on what you prefer.

Make each switch a LED which -if they are- signals ON-state as the screen is turned on or off.

Edit: And incoming call screen would have to reflect the mic being off, in which case flicking the switch would accept the call.