I have this exact problem too. But it's not linked to mint, or linux. It happens on windows 7 and 8 (beta) too.
My hardware is different Q6600 on nvidia chipset (socket 775). Quite not ivy bridge stuff. Over the years, I removed the sound card, plugged it back again, changed the graphic card, the cpu, the OS, etc, and the freezes stay... and go. It seems there are spikes in the frequency of the freezes for some weeks, then they calm down. I remember a time it happened several times a day (like 3 years ago), sometimes as soon as I moved the mouse in windows seven (and then it ran flawlessly for hours), and then I had no freeze in weeks, if not months.
I suspected everyhing. The nvidia chipset first, the sb x-fi extreme sound card second, the 8600gts, then the 8800gtx, the soft raid, the disks, sata, the cables, memory timing, even my beloved seasonic power supply. But the freezes are not linked to anything I can point, even room temperature. This one is a real puzzler. No matter how hard I look, I see no pattern. Neither google or system logs show anything significant.
They did seem to occur less frequently with windows 8 and mint 13 cinnamon, now I'm on 14, and they poked their ugly head back (I had two yesterday evening in 2 hours, but none today in 10 hours), but I strongly doubt it's linked.
Of course my freezes might be caused by something entirely different than other's freezes but the symptoms are the same exactly, down to the repeating, and very annoying, 0.5 sound loop.
Basically, I have learned to live with it. It has become my pet bug, I go get some coffee when it comes. I concluded it's the way my computer shows his love. And today I learn I'm not the only one