ubuntuforums.org says:
* Install PULSE audio control (sudo apt-get install gnome-volume-control-pulse)
* Set the Input slider in this to maximum (it is installed as gnome-volume-control-settings)
* Change the Device in gnome-sound-properties to “Playback: HDA Intel – STAC92xx Analog (PulseAudio…”
* Change the Audio Conferencing:Sound capture drop down in gnome-volume-control settings to “PulseAudio Sound Server”
* In Skype – Options:Sound Devices leave Ringing and Sound Out on “HDA Intel (hw:intel,0)”. Set Sound In to “pulse”.
