Sometimes you run into a problem and do a Google search and up pops a solution that instantly solves your problem. This is what happened when I realized that I didn’t know how to switch my sound input and output from the computer microphone and attached speakers to a USB headset that I wanted to be able to sometimes use. I was messing around with various software settings every time I needed to make the switch.
Thankfully, Stephen Ostermiller had this same problem in Ubuntu 13.04 and wrote a script that automatically switches your input and output to the USB headset when you plug it in and turns off the default microphone and speakers. You can read about it here: http://blog.ostermiller.org/ubuntu-usb-audio/