This has been driving me nuts; audio on the Gmail call feature used to work quite well, until one day it stopped detecting my microphone completely. I'm on Windows Vista (I know, I know), and Skype, etc work perfectly; so does the new Google audio search. And yes, I've tried every combination on the settings panel, many many times...no dice.
what I did find, however, was that rolling back my system to about 2 months ago fixes the problem...so I figure it's an update issue? Anyway, I have tried and tried to figure out what update is causing the problem, but have been unlucky thus far; the only one it kept coming up with was the Windows Defender, which I disabled completely without results....
anyway, I'm at the point where I can't simply keep restoring my computer to an earlier date for obvious reasons...any ideas?