How to unmute?

This should be dead easy, but I just can't find a way to hear myself in a meeting.  For test purposes, I'm making a recording of a meeting with just me, so everything is on my Windows PC.  When I speak, my audio is in the recording, but I can't hear myself live.  I've been having a distortion problem and I want to try different settings to hear what I'm getting, but there is absolutely nothing on my speakers or headphones.  I can make a new recording every time I change something and then listen later, but that gets real tedious real fast. 

This is a new problem;  I had no problem for years up to about a week ago, but I didn't knowingly change anything.
There's gotta be a setting somewhere, but I just can't find it.  So how can I unmute myself for myself?