tbhausen So I guess it could be said they all buzz, to a degree.
Notice that @tombkk had measured the buzz as a modulation on top of a 10 kHz carrier.
As you age, you ears start to cut off. In my case, the -3 dB point is somewhere around 8000 Hz! A 10kHz tone is about half an octave away, but still probably quite attenuated.
Bring a pet near to the ASIAIR, see if they get irritated. Dogs usually have good hearing.
When I was younger, I used to be irritated by the flyback transformers of TV at 15.75 kHz :-). I could not be in the same room with most TVs, and even some CRT monitors.
Chen