Ubuntu: How do I make my built in microphone default again?

Ubuntu: How do I make my built in microphone default again?

I connected an external microphone (mic), and now it's the default mic. I know it's the default mic because when I use Skype the external mic is the only one which works on the default sound input. The internal works only on HDA Intel (hw:intel,0) and its the only mic that Rosetta Stone is picking up which is the external one. All I need to know is how to make my built in one default again.