For several months I've had an intermittent and infuriating problem in my Skype For Business voice calls. My microphone level gradually eases its way up to 100% causing horrible audio quality and drowning out my conference calls with noise.
I tried several suggestions including disabling application exclusive access to the device and setting "When Windows detects communications activity: None", but to no avail. The problem was that it was intermittent and I couldn't find any specific correlation for the issue.
Today I found it. It's a Skype (not Skype for Business) setting. (Skype for business users, see the note at the end of this post.)
To get to this setting, click the little "..." Next to your Skype name in the upper left corner of the Skype UI. Then Select "Audio and Video settings". On the next screen, click the "Automatically adjust microphone settings" toggle switch from green to gray.
NOTE: If you are using Skype For Business, it also does this. I write about how to fix it here: