The GE side by side is a refrigerator with two side-by-side doors. On this unit, the refrigerator is on the right and the freezer is on the left. As you use the appliance, you might encounter a variety of noises, including a whistling sound. When this happens, it's possible to determine the cause of the noise, without calling in a professional for repairs.
If you only notice the whistling noise when you close the doors, this is a completely normal sound for the refrigerator. When you close the doors, the unit acts quickly to seal the doors and equalize the pressure in the unit -- resulting in a whooshing type of whistling noise, which is normal.
The compressor is a component of the refrigerator that works to keep the unit cool. As the compressor runs, it speeds up and slows down. When this occurs, you can hear a high-pitched whistling or humming sound. The sound is completely normal. If you replaced an older refrigerator, the compressor on the GE side by side is likely louder than than of the older unit.
The refrigerator fans help regulate the temperature in the unit. You will notice the fans making a whirring whistling noise when the doors are opened frequently or when you add a large amount of food to the refrigerator. This is also the same noise you hear when the unit is first installed. It is normal and occurs regularly during normal usage of the refrigerator.
The GE side-by-side refrigerator has a Frost Guard feature for the freezer. It protects the food in the freezer from getting freezer burn. It also improves food preservation. It does not run all the time, but when it does, you can hear a loud noise that mimics a whistle. This feature most often occurs when the door is opened frequently.