Comment 25 for bug 459083

This solved the problem:

http://ubuntuforums.org/showthread.php?p=8881261#post8881261

It is the first time that I've ever been able to use the external microphone.

I find that there seems to be confusion or a lack of clarity in many of the forums with respect to hardware. Although desktops and laptops have become more similar, the prevalence of laptops and portable computers in general have made finding solutions messy, especially for desktops. I was fortunate enough to find this solution in this case.