If I think this is the make we have - 'German' all I can say ours does not make a noise.
We did have problems with the thermostat, which was simply a bi- metal on/off thing, - arcing.
I got a new one (very costly) and then arranged a Relay at the rear of the unit in a box to bring the comppresor on with the contacts on this relay not the thermostat direct.
These contacts have capacitors across them as does the therm contacts
We could tell it was the thermostat, as the arcing only took place if the Compresor was running and was brought on with the thermostat contacts. operating the "Quick freeze" switch (which usually simply shorts out the thermostat contacts) did not produce the arcing noise, which was both Rf based and audio band QRN
Touch wood - no further problems.
If I remember right the thing was perfectly straight forward wiring in a plastic box at the rear.
There is a power factor capacitor across the compresor motor.
Maybe yours has an "Electronic thermostat" or something?
Check the unit is earthed! Try Ferrite before going to all the problems I did above.