People trying to install Skype on Ubuntu 13.10 is experiencing several issues: application crashes, audio is not clean or doesn't work at all, etc...
The problem is common...and probably it's due to the way Skype is installed on your system. What everybody (most of the users) does is to download the .deb package from the Skype website (http://www.skype.com/it/download-skype/skype-for-linux/)...WRONG!
There's a better and cleaner way to install Skype that doesn't cause all those issues.
You just have to follow these steps:
1. Open the Terminal (Ctrl + Alt + T)
2. Paste the following
sudo add-apt-repository "deb http://archive.canonical.com/ $(lsb_release -sc) partner"
3. Update the repository
sudo apt-get update
4. Install Skype
sudo apt-get install skype && sudo apt-get -f install
You have successfully installed Skype on your Ubuntu 13.10