I looked in the Sounds preference pane in System Preferences, but there is no option to override this. I want the computer to use the built-in mic on my MacBook Pro, but I want to be able to use my headphones (which have a built in microphone). I have to hold the mic up to my mouth practically, but with the built in mic I don't have to. I have played with the input volume in System Preferences for each option; still doesn't work how I like it. This is for video chat in iChat. Thanks!