How to convert 1 channel audio to 2 channel?

Hi,

This a noob question but for some reason i can't figure it out. I recorded an audio using and external mic and when i sync to my clip in FCP7, it turns out to be on channel, and you can only hear from the left speaker using a headphone. My question is how do i make so it sounds in stereo ot two channnels, in soundtrack pro perhaps FCP7? Thanks in advance for any replys.