Hi,
My landlord has an 8 year old Whirlpool (http://dn.dnweb.net/fridge.jpg)fridge with a top freezer compartiment. Every time its temp control turns the fan or the compressor on, the humming sound vibrates loud enough to keep me from hearing my TV well. It's annoying and I sometime hit it to lower the sound.
Here is what I have done already:
- secured bottles and cans inside to make sure they didn't make the noise by lightly vibrating against the walls or racks
- secured the temp exchange grill in the back which could have acted as a resonator
- looked for the location of the noise and it seems to come from the fan and not the compressor

Please help! My landlord won't change the damn thing and the noise is driving me crazy. I am handy and just need advice short of chanbging it at my expense...
Thanks for sharing.
Dan
PS: my fridge - picture of manufacturer plate info (http://dn.dnweb.net/fridge.jpg)

Many times the condenser fan gets dirty and out of balance. I would disconnect the fan for a moment and see if the noise goes away. This way you can see if the fan is the actual noise maker or not.