League Voice Chat Not Working???

So I'm playing league, as usual, and I try to communicate with my friend in voice chat on league, but it's not coming up. As int he green circle that surrounds your icon doesn't show up when I talk. I check my settings and make sure they're set to my preferred settings. It's not working. When I try to adjust the volume, because they look like they're set to 0, it goes from 100% to NaN%

like the image above. I hear my friends, and can listen, but I can't speak for some reason. Anyone got any idea what this is?