Media plays automatically when 'autoplay' is true. (audio)
Test Assertion
Test passes if the text 'PASS' appears to the left and the text 'Your browser does not support media elements.' does not appear anywhere on this page.

http://www.w3.org/TR/html5/video.html#attr-media-autoplay

The autoplay attribute is a boolean attribute. When present, the user 
agent (as described in the algorithm described herein) will 
automatically begin playback of the media resource as soon as it can do 
so without stopping. 

Your browser does not support media elements.