Is it possible to echo what your mic records to the speakers?
I would take a look at Rogue Amobea's application LineIn. LineIn is a free app and can be found at http://www.rogueamoeba.com/freebies/.

From Rogue Amobea's site:


  LineIn is a simple application for OS X to enable the soft playthru of audio from input devices. In simpler terms, you can use LineIn to play sound coming in through a microphone or any other device plugged in to your Sound In port, just as was once available with OS 9's "Play input through output device" option.