I don't think so, as chit chat is not one single frequency (band) which can be filtered easily without compromising the rest of the audio.
What is it you want to have heard better without the chit chat? Maybe you can apply a band pass filter (I don't know the FCP 7 audio capabilities), to mute or lower a certain band of frequencies like 800 Hz to 3500 Hz but as that is the area of many important audible frequencies, you will definitely lose audio quality.