This gallery of mute buttons shows why voice chat apps should be push-to-talk

Dave Rupert put together a gallery of voice chat app screenshots, to show how the mute indicators are inconsistent across applications. For example, the mute indicators for the iPhone and Slack are almost opposite from each other. (See above).

He writes:

I hope you, dear reader, know by now that its a best practice to mute yourself if youre not talking. Normally Id say non-muters deserve public shaming but looking at this chart, its maybe not the non-muters fault. As you can see, the active mic indicator varies wildly. Sometimes its a microphone with a background fill, sometimes its a microphone with a slash, sometimes muted is treated as a background fill with a slash, sometimes the icon fills up with green when talking. Its all even more confusing if someone is sharing out their screen and your entire UI disappears.