I installed Skype 4.2 via PPA on my fresh 14.04 system. 
Skype itself makes notification sounds (though distorted), but when I am in a conversation, I receive neither sound, nor video. I tested it with my mom, she could hear and see me, but I couldn't see or hear her, and the sound test is quiet too.
I didn't install any additional drivers yet, as I'm much of a newbie I'm not sure which ones to choose. Please let me know if you need any command outputs.