Almost any place in Moodle where you can add text using the text editor, you can include an audio or video file that you create on your computer. This would include labels, descriptions, wikis, forum entries and so on. The only exception we know about is when creating email. In that case, although the creation appears to work, nothing will be sent with the mail.
This is an Amherst College developed feature. You should not expect to find it on other Moodle installations. It assumes that your computer has a microphone and/or video camera.