You can hear your refrigerator???
I think they're using different kinds of motor windings, bearings, insulation, etc. it's not related to the refrigerant or other system parameters. I've had older r600a fridges that were dead silent compared to anything sitting in a Best Buy showroom right now.
The advantage of the newer variable speed scroll compressors in some high end fridges is that they can run continuously at a slower speed.
I guess all of the places I've lived the kitchen was always its own room, maybe adjacent to the dining room if anything.
No new appliances (>10y now I think about it, they came with the house.)