I have turned off the room's mini-fridge a few times when it's been a problem. Fortunately that's rarely the case. A smooth, quiet hum from a unit that's working well doesn't bother me. Often the device is in a cabinet, anyway, which further muffles its sound. If the compressor sputters and rattles when it runs, then I'll turn it off. I estimate it gets to that point in fewer than 1/20 of the rooms I stay in. To put that in perspective, at least twice as often I call down to the front desk to request a new room because of noise-- street noise from outside the window, machinery noise and human chatter from being too close to the elevator, etc.