No, attendees will not have any controls by default. However, if the Instructor wants, the audio-video rights for the attendees can be activated by clicking on the Mic/video camera icon next to the attendee name.
You can connect a good quality headset with mic for audio communication. Alternatively you can use inbuilt mic and speakers of your computer/laptop to communicate in the Virtual classroom, but we recommend use of headset with mic to avoid echo ...