Computer sound animation was used during the making of Chewbacca's voice. This software is often used in movies that require creatures such as Wookiee's.
I'm not sure if they used a specific one or...
By hitting a metal slinky with a pen/pencil. If you have a metal slinky at home, hang it down your stairwell, so its falling to the ground. Then, take a pen or pencil (preferably a pencil - the metal...