If I allow an external microphone to be accessed by FireFox, and unplug it, the internal microphone is then also accessible
tested using voice.google.com
Additional System Details
- Shockwave Flash 32.0 r0
- User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:70.0) Gecko/20100101 Firefox/70.0
I don't believe Firefox is able to distinguish between an external and internal microphone, hence why the permission is simply labelled microphone.
You might be able to restrict Firefox permission for a specific microphone device from without your operating system settings.
Hope this helps.
The drop-down box lists it as the "external microphone" which could be a text error. The operating system would allow the browser to know which microphone, external vs internal, is in use
Are you able to attach a screenshot of where Firefox gives the option between external and internal microphone? I don't see that option on my browser.