Do not change the state of the microphone mute GUI button unless the user clicks it.
The behavior of the in-app Mute function is inexcusably invasive. The state of the mute button in the app should never be changed unless the user clicks it. If I mute or unmute my microphone at the hardware level, the software shouldn't change its mute state.
Andrew Hunkins commented
I agree with Mark (and disagree with the posted idea from Justin). The tight integration of mic controls and the client are a feature advantage over most other web conf solutions. I wish I had a penny for every time a Webex user complained about being on "double mute". LOL.
Why? I wan the GUI to reflect the status of the mic. If I mute the mic on my headset, I want to see in the display that I'm muted. Why would a person want to see that they are not muted, only to find that they were hardware muted?