https://gist.github.com/721253
Load it as a bookmarklet using this:
javascript:(function(){document.body.appendChild(document.createElement("script")).src = "https://gist.github.com/raw/721253/f70c2bdeaed54d9907a448504...
EDIT: the bookmarklet is getting cut off by HN, see the first comment on the gist linked above.
Unfortunately there's a little bit of delay due to loading the sounds but it sort of works.