Get a pressured air can with a nozzle and get that 8" away from the mic hole and shoot aur at it, itll clean out the hole. I think mine is messed up because u went to beach a while ago and every time i go i always manage to get sand in my devices mic...pressured air fixes all. You can get a can...
I have duolingo and the mic thing just means the verbal feedback on app which requires mic wont be enabled fir an hour, thats only limited to the app, your mic isnt actually being turned off, im pretty sure thats not even possible to turn a mic off