If your microphone is not working
Use the phone number listed in the Zoom invitation when you set up a Zoom call. You can use your phone as the microphone and audio source for your call rather than your computer’s built-in microphone if necessary.
If your Internet connection is slow or lagging
Consider temporarily turning off your video stream and only maintaining the audio stream. Sometimes, running the web camera on your computer will use up the Internet’s bandwidth in a way that might make communication challenging. Turning off the video should improve communication quality and consistency.
If you have earbuds or a headphone set, wear them!
Wearing earbuds or headphones will reduce the amount of noise that your computer will pick up during your quality, which will make it easier for your class to hear you.
Check the Zoom Help Center