When I click on the microphone icon in the Cortana search box on my Asus laptop running Windows 10 x64 16299.98 I don't hear the tone that Cortana normally plays when she used to do when she listening to me (and continues to do on my work laptop and my Lumia 950). Instead I see Tap here to make sure Cortana can hear you
I don't have the greatest built-in microphone in the world, but when I've tried the voice test number on Skype I can hear myself okay. I would expect that if Cortana couldn't hear me I'd hear the "Sorry about that I didn't hear anything." message.
I've followed the Tap here link to both the "I can't hear Cortana" and "Cortana can't hear me." If I follow "I can't hear Cortana" I get taken to this:
I don't see anything to change (and I can hear the test sounds it plays afterward).
If I follow the link to "Cortana can't hear me" I get taken to:
but it doesn't fix my problem.