Capture in FCE, video okay but no sound

[lloyds]

I'm trying to capture from the camcorder into FCE via firewire.    When
I first hit the capture keys, I get a window with color bars and the
message "Preview Disabled." I hit the play button, the color bars
disappear, the computer controls work, the video plays but there is no
sound. Is there some control that I'm overlooking?  I'm brand new to
FCE, so apologies if this is just a dumb question.

BobLL