You can do it in FCP, but if one is somewhat apprehensive using audio effects, it may be helpful and is certainly easy to use presets in Sound Track Pro. It's a pretty good visual way to acquire an understanding of EQ while working with it.
If you bring your audio into Sound Track Pro.
Click on the effects tab.
Choose EQ from the category list.
Double click on Channel EQ to open the plug-in.
Click on Show Presets.
Click on the disclosure triangle EQ Tools.
Try the Megaphone EQ and Phone Filter Wide Band presets for example as a start. Feel free to adjust the preset curves and master gain to suit.
If in a room I tend to use Space Designer/Reverb on the track to get a sense of and sell the room ambience also.
Another useful tool IMO and perhaps worth mentioning here:
http://www.audioease.com/Pages/Speakerphone/speakerphone_themovie.html