Is your feature request related to a problem? Please describe.

I would like to be able to mute microphone easily during online calls in Skype, Teams, Zoom and browser-based VC apps.

Describe the solution you'd like

NVDA keystroke that mutes/unmutes microphone. I propose to bind it by default to NVDA+Delete.

Describe alternatives you've considered

1. Windows 11 claims to have Win+Alt+K global keyboard command to mute/unmute microphone. However that's not true. Quick investigation shows that it only works in Microsoft Teams. Ironically, it doesn't work in Skype, a Microsoft application too. There is evidence all over Internet that it doesn't work in a bunch of other VC apps. Even if it works in Teams, there is no spoken notification, so NVDA users won't know whetehr the mic is muted or unmuted, rendering this keystroke useless.
2. Some Laptop manufacturers have a keystroke on the laptop, such as Fn+F4 for Lenovo. However this is not a good solution either, because again it doesn't trigger any spoken notification, and it doesn't work with external keyboards.
3. Using mute button in your particular VC application is typically too slow. The use case for people working in large IT companies is they are on mute during VC calls most of the time and doing something in other applications. Then someone calls them out on VC, and then the user needs to unmute quickly. Trying to alt-tab to the right application, and then finding the mute button in that application might take 10 seconds or even more - in practice that's enough for other people on the call to assume that the user has fallen asleep and move on. That's why I propose this new keystroke to quickly unmute the mic.

Additional context

Prototype is implemented in Tony's enhancements add-on.
Prior discussion: #16037