When using Skype on openSUSE 13.1 a crackling sound or distorted noise can be heard. This might happen already during the start-up. Sometimes also no sound at all can be observed.
It is actually a bug in Skype, which has become obvious through a new feature in PulseAudio 4.0, that allows to deal better with automatic latency adjustment.
Start Skype with the following environment variable:
Please note that this can be set in the same manner in menu or icon entries under GNOME, KDE, etc.