How to reduce noise from refrigerator?

I was sitting there. The noise from the refrigerator is very loud. The noise is so loud that I want to unplug it. I pull out the refrigerator a little bit so I can reach the plug. Magically, the noise stopped.

This must be due to the increase of space at the back of the refrigerator. This makes the releasing of heat easier. The refrigerator doesn’t have to work as hard. The noise disappears or reduces.