Here's something I did to slightly improve things. Buy one of those timed switches that are usually for outdoor lighting and things like that, and use it to switch the fridge off automatically during periods you need quiet the most. Obviously not too much of the day, use good judgement. Fridges are only working (and whining) when the temperature inside rises above a certain amount. With the timer you can have a little influence over when that happens.

Pray for me as I am stuck in an apartment building with a regular 50hz hum for the foreseeable.