Today, surveillance techniques exist that can activate your webcam or microphone without your knowledge. In 2011, New York Times wrote about the spyware antics of the German Police. They also reported on the flourishing industry of spy tech firms that would look at home in a Jason Bourne movie.
In short: any interface device like a microphone or a webcam is a privacy concern.
The tried-and-true hack of using tape works for webcams, but not for microphones. Therefore, you need to disable the microphone altogether. However, this technique will not work if someone has deployed a RAT to attack your machine.
Disabling the microphone has other everyday uses beyond privacy — for instance, to block it from picking up any noise at all while trying to record something. Also, it could be a barrier against websites which ask permission to use your microphone or camera.
Disable the Microphone in Windows 10
Right-click on the Start Button and open Device Manager.
In the Device Manager window, expand the Audio inputs and outputs section and you will see your Microphone listed there as one of the interfaces. Right click on Microphone and select Disable.
A dialog box will prompt with a warning. Click on Yes, and now your mic will not function. You can follow the same steps to Enable it again.
This straightforward method also works in Windows 8 and 7. (It’s also easy to block the camera and microphone on your Mac after the Mojave update.)
I had an old laptop that would not disable the internal mic by default when I plugged in an external microphone. Disabling the microphone from the Device Manager helped resolve the conflict.