Ubuntu / Linux Mint Audio Bug
Update: Apparently this bug can affect Linux Mint 14 as well (I just encountered it). The fix is the same.
Ubuntu 12.10 and Linux Mint 14 (which I use because Unity is a steaming pile of garbage) have a bug related to audio on new Thinkpads (I just got a T430s, really happy with it so far, thanks for asking).
Anyway, apparently the speakers stop working if the computer is suspended while the wireless is enabled. Yeah, convoluted, but why not, right?
Anyway, after reading through the bug report and comments, I found another bug report with a similar problem. It's not entirely clear that they are the same issue, but whatever.
There are a couple suggestions listed there. I always try the least-invasive solution first. In this case that meant disabling "Automute mode".
That will bring up a fun terminal application that lets you adjust audio settings and such. Scroll to the right with the arrow keys until you find "Auto-Mute" and change it to "Disabled" using the Up/Down arrow keys.