Did more research in my problem and found more info from the following page:
A-1Appliance.com :: View topic - GE Side by Side Refrigerator Howls
This led me to suspect that replacing the evaporator fan won't fix the noise and that the
control board is the culprit.
I called GE for info since the post states that certain models and SN's had a free replacement part for the defective control boards. Unfortunately my SN didn't qualify since it was manufactured one month before the start date of the replacement program (April 2005). I was offered the replacment part for 50% off GE's price ($56) with free shipping. I accepted the offer and am waiting for the part to be delivered.
I hope this solves the noise problem. From what I've read, it's an easier fix to replace the control board than the fan. If the control board replacement doesn't work, I'll buy the fan next. Either way, it's cheaper than paying a repair tech to come to the house in my part of the US.
Keep you posted.