Comment 4 for bug 311497

Changing your sound in to hw or plughw for Sound In (Skype options) may help for skype-to-skype calls. The problem here is two fold, and is affected by pulseaudio (in particular, its buggy ALSA plugin) as well as the network stack. Skype uses two different audio encodings. One for skype-to-skype, and another for skype-out. The former uses larger packets and works fine, while the latter uses smaller packets, and the network stack is unable to handle it. So for me, calling skype-to-skype works fine, but skype out still has major lag (sometimes over 10 seconds).
There should be a new linux version of Skype out sometime soon... maybe... crossing fingers... which is supposed to work better with pulseaudio. But if I'm right about the network stack, then it might only solve issues with skype-to-skype calls, and not skype-out calls.
Haven't tried pasuspender yet though. Will try that later today.