@IraNichols ...

While I don't know the details of your test, if your instructor was requiring you to record your voice with a microphone, that would be a question you'd need to ask your instructor.  I'm not sure what kind of computer you are using (desktop/laptop), but generally speaking, laptop computers these days usually come with a built-in microphone/camera.  Depending on your Desktop set up, some monitors *may* have this as well...or you might need to purchase a separate web-cam.  But, to just view videos (such as on YouTube, Vimeo, etc.) you shouldn't need to use a web-cam or microphone.  Again, check with your instructor about any special requirements for your test.  You can contact your instructor via this link:

How do I get help with Canvas as a student?

Hope this helps!  Good luck as you have conversations with your instructor on this topic.