Zoom is great and useful, but people do sometimes have audio issues, especially if you're in a loud room.
There is a default setting in zoom that is the cause of the problem if you're in a loud room
This is how to fix that setting.
Click on ^ next to mute
Click Audio Settings
Make your settings look like this, Lower the volume slightly
Click off Automatically adjust Microphone volume
set suppress background noise to low
You can now close the window! There is no save button! enjoy better sound for your guests on zoom!