If your refrigerator is new, the continuous noise you are hearing is normal. The refrigerator has to cool down once it is installed and turned on. The cooling process causes the walls of the refrigerator to expand and contract, which results in noises. Once the unit has cooled, the noises should stop.
If you are frequently opening the refrigerator door or standing with it open for a prolonged period, you can get this type of noise. The noise likely does not start until you close the door. This noise is the same one you hear when the unit is first installed. Opening the doors frequently or leaving the doors open too long makes the air in the unit too warm. When the doors are closed, the refrigerator has to cool down the warm air. This causes the same expanding and contracting of the inside walls as a newly-installed refrigerator. Opening the door less often will make the noise less continuous.
When you add a large amount of food to the refrigerator at one time, the unit has to work extra hard to get it cool. This extra effort also causes the interior walls to expand and contract. If you refrain from putting in a lot of items at once, you can prevent this from happening or at least not be continuous. Putting in a few items at a time, you give the unit time to cool without working it too hard.
If the noise seems to be coming from the freezer area, it may be from the ice maker. If ice gets lodged in the ice maker, it can result in this type of continuous noise as it repeatedly tries to eject the ice. The only way to stop this noise is to remove the ice that is blocking or clogging. Do this with a wooden spoon or even a plastic utensil. Once you have removed the blockage, the noise should stop.
If the ice maker is on, the noise you are hearing may just be ice dropping into the bin once created. Thus, try turning the ice maker off and listening for the noise. This helps you determine if this is the cause of the noise. If so, only stopping the ice maker will stop the noise.