[SimpleMinds]

"activity in the input monitor"

Hi. Are you sure about that?

Using one of the other tools mentioned here (Oversight) it looks like Microphone starts when you open Input and closes when you close Input tab. Which makes sense as you do want to see Input feedback instantly. Mac 10.11

[yolesaber]

The point is that your mic is 'hot' if you don't turn the volume all the way down. You don't need root access to run 'sox' or other audio capturing scripts. Very easy to eavesdrop, as this Shazam example illustrates.