I have a problem with Skype: there is a high level of noise in my microphone (20-30%) when I'm talking via Skype. Skype for Windows has software noise cancellation, so it works fine, but Skype for Linux hasn't.

I've found that there is a PulseAudio module webrtc-aec for noise and echo cancellation (described here: http://wiki.gentoo.org/wiki/PulseAudio).
How can I enable it in Ubuntu 13.04?