Prolonged soft noise from refrigerator.
When the internal temperature is not sufficiently cool, the compressor and fan motor will run
at a higher speed in order to cool, causing a prolonged soft mechanical noises. Noise levels will vary
depending on the surrounding acoustic conditions, the model and the set and ambient temperatures.
How to fix
The product will run at different speeds depending on the above mentioned variables
however it is a normal phenomenon, not a defect of the product.