Converter high frequency sound

[markgable]

So I did the LED bulb conversion for my whole camper and now when I turn the lights on, any or all, I get a super high frequency sound from the converter. My wife cannot hear it but I hear it clearly and it gives me a headache. I also noticed that if I plug one of my incandescent bulbs back in a fixture and turn it on, the sound immediately goes away, turn it off, sound comes back.
Is there a remedy for this? It is a Progressive 9100 series converter...the fan is fine.