话筒突然不工作了

UBUNTU dapper，前段时间一直工作的，今天一用skype，居然罢工了。
首先怀疑是硬件的原因，但无法检查，再怀疑是OS的问题，于是切换到WIN下，一切正常。

问题应该处在最近安装的软件上，检查系统的历史记录，发现最近只安装过SKYPE 1.3。
有可能是skype的问题，于是google之。找到了答案：
http://taint.org/2006/06/07/150917a.html

There is a solution for the Skype microphone problem:

1.

Install Skype 1.3 beta (see http://www.macewan.org/2006/06/28/skype-13-ubuntu-dapper/#comments)
Do NOT run it during working on next point.
2.

Go to your sound channel settings (i.e. right-click the reproductor icon in the Gnome interface and select “Open volume settings”) and make sure that both Microphone AND Capture channels are selected as recording devices.
And yes, I also had Capture off in Breezy with Skype 1.2, but now it is needed to have it on or the microphone will not work. It is probably good idea also to enable the capture “output” which in fact enables automatic volume level control of the microphone.
3.

Run Skype

Another possibly affecting factor is that I have installed the oss-alsa package as result of my previous attempts to get skype to work (I do not know if it matters or not).
This way it works for me, I hope it will for you also…