Attention CSS Gurus

Okay, here's an important feature request that I have, either for someone to code as a stylesheet or (assuming no browser supports the necessary level of CSS that'd be required) a Firefox extension:

Please play back the Windows "tada.wav" sound file whenever I'm viewing a page on the site and either valid-xhtml11 or valid-xhtml10 image is displayed.

I'm thinking something like

.inline-badge { play-during: url("tada.wav") mix !important; volume: x-loud; }