Personal pet level is that it’s so hard to get information on the noise level of appliances.

We’ve recently moved, and our new house’s crawl space has a Santa Fe dehumidifier in it that seems SO LOUD at night. I don’t think it’s broken - it’s just a compressor and fan with no engineering put into keeping them quiet. If I could get one that was as efficient and well built, but I knew would be quiet, I’d replace it in a heartbeat - but manufacturers don’t advertise noise levels.

Surely I can’t be the only one who’d pay substantially more for an appliance that was guaranteed to be quiet?

I would try plugging a simple induction motor into the refrigerator circuit to see if it also makes a weird noise. It's possible you have a problem with the wiring itself (loose neutral, etc.).

I've never had issues with HF noise out of a refrigerator. It's always been the opposite kind of noise that has been a problem.

The newer compressors are smaller so they cost less, but are run faster to pump at the same rate. Many old hermetic compressors used a 4-pole 1500/1800RPM motor, then they became a 2-pole 3000/3600RPM, and the newest VFD/inverter motors can go even faster.

My Miele hums with so low frequency that it sounds like a truck is passing by.