I don't seem have any specific sound feedback from this control unit car such as flange, rail joints (where applicable), wheel rub, groans, etc. I have noticed this issue on the Main-Spessart Bahn DLC. I haven't tested on the Ruhr-Sieg route DLC with this unit. Basically it's gone quiet a lot like the sound issue which is now resolved with the CSX Freight cars.
Unit 767.2 DABpbzfa on Ruhr-Seig Route hasn't got sound issues at the moment, it works fine. I checked