If you have a Virtual Classroom account and your class doesn't display audio and video for you, please check the class configuration. It's possible that the class may be set up to be "whiteboard only".
The Virtual Classroom has the option to create classes where the teacher would like to share only the whiteboard with their students.
If a class is created as a "whiteboard only", you can edit it.
Simply go to the list of upcoming classes, click on "Edit", then deselect the "whiteboard only" field.
When creating a class, always remember to double-check your settings.
Happy teaching!