I have Chromium installed on Ubuntu 13.04, but aside from flash things, it seems I can't get a sound out of it.

For instance, I installed an extension, SpeakIt, which is supposed to read paragraphs aloud, but I get no sound out of it. The test includes listening to an audio file, I don't get anything out of that either.

I do hear sounds when played by YouTube, which makes me believe that the computer's sound itself isn't a problem, only Chromium's (because Flash makes sounds).

I don't hear sounds the browser plays (like Google Translate's speak).

What can I do to troubleshoot? What could be the problem?

When looking in the Sound > Applications submenu, it doesn't even show up there. When I play a YouTube video, it does show.

_{Example of what happens when YouTube video is playing}