Can we get sound for when we receive a PM the same way we do for notifications?

I tend to browse other sites while I'm here, and seem to always be unlucky enough to miss PMs from people I've chatted with before. By the time I've checked back here, they're already offline. ):

(That, and I'd rather not have to glance at this site every 5 to 10 minutes if I'm busy with other things.)