Comment 68 for bug 408903

I have a T430 running 12.10 and can confirm that the key is not working.

xev outputs nothing when the key is pressed/released.
acpi_listen outputs:
        ibm/hotkey HKEY 00000080 0000101b
input-events 5 outputs :

EV_MSC MSC_SCAN 26
EV_KEY KEY_MICMUTE (0xf8) pressed
EV_SYN code=0 value=0
EV_MSC MSC_SCAN 26
EV_KEY KEY_MICMUTE (0xf8) released
EV_SYN code=0 value=0

Not quite sure what course of action I should take, but I found this page (http://askubuntu.com/questions/125367/enabling-mic-mute-button-and-light-on-lenovo-thinkpads), and it seems like a very similar solution to that of Chris Van Hoof's.