Admin's info is old and doesn't guide you to the necessary settings, at least for Firefox.

If you are using Firefox then do this:

Open "Settings"

Click "Privacy & Security"

Scroll down to "Permissions"

Click [Autoplay] "Settings" button

Set to "Allow Audio & Video"

Click "Save Settings" button

If you're using a different browser then you will need to let us know.

Sascha