I really appreciate this comment.... I always wondered why it's so hard to make music quiet behind voice tracks. But the words you used don't make any sense to me and they're not that easy to Google. I did poke around a bit though, and I think what you're talking about is referred to as "ducking"?

For those who want to apply this technique, it's built into GarageBand: http://www.youtube.com/watch?v=ulfKubMdxPA