Enabling the internal microphone of a Lenovo Thinkpad T61

This time i'm going to talk about something that bugged me for quite some time. Since i got my new shiny ThinkPad T61 and installed a fresh Debian unstable (or sidux, but who cares, really?!) on it, i never got to make the internal microphone to work. This is especially bugging, since lately i'm "forced" to use skype a lot, and skype is not much fun if your communocation partner can't hear you while you hear him loud and clear. Since shouting at the two little microphone holes on the T61 palm rest didn't help either, i decided to take a deeper look into it. At first i was trying to fiddle around in the skype settings, because my naivity let me think that it has to be the fault of the evil closed-source software. Despite skype neing crappy in a lot of ways, this particular problem was not caused by skype.
The T61 has an Intel ICH8 HD Audio device, which is suported by alsa's snd-hda-intel module. So maybe other notebooks with the same sound device might have the same problem. Googling around for a bit i found out that some T60 users report the same problem. So it was either a driver problem or some misconfiguration from me.

Turns out it was not a driver issue, at least not for my kernel version: 2.6.24. So, here's how i got the microphone to work:
First of all, in skype's configuration dialog for audio devices set all devices to "default". Now, from a console run alsamixer and you should see something like this:

This view doesn't matter for activating the microphone, so press to switch to the Capture view:

In this view you need to make some adjustments. The problem is, that the device names are somehow misleading, e.g. there are two microphone devices: Mic and Internal Mic. Here, Internal Mic is the one that is integrated into the T61's palm rest. Therefore you need to set the Input Sources to "Internal", as shown in the previous screenshot. Additionally you can increase the "Internal Micorphone Boost", which is the rightmost slider. But these changes still won't let you record with the microphone. One other, not so obvious, thing is needed. To finally enable recording you must set the "Capture" device as recording device. This is done by selecting the slider called Capture (2nd from the left) and pressing space, which results in this:


To improve the recording level you should fiddle around wiith the "Capture" and "Internal Mic Boost" slider.
That should be it, just don't remember to turn the recording device off after you're done.