Check your volume.
You have settings that may have changed. Here's how to adjust the volume of your mic.
What if sound isn't working in Oncourse
1) Clear browser cache
Go to the three dots at the top of your screen.
2) Restart device
3) log into OnCourse Classroom
4) click microphone
5) Click pop-up box that says “Allow Mircophone” top left next to address bar.