Display Mic volume in the menu bar In MacOS Mojave, I want to get the Mic volume icon to the menubar, just like the speaker volume icon. How can I do that?

Like this.
This app works for me: MuteMyMic. Available in the App Store at that link. 

Appears to be free, as well.

It puts an icon in the menubar with a mic input level slider:



Disclaimer: no financial or other ties to the developer of this amazing app which I just found using Google.