My street side tank regulator makes that noise whenever propane is being used. Changing the regulator made no difference. The only good thing is that when it quits making the noise I know that I have an empty tank to refill.
Lenny and Ros
2012 Montana 3400RL,680 Watts Solar,4xT-105 Trojans,GP-ISW2000-12 Inverter,Trimetric 2020, EMSHW50C
2009 Chevy Silverado 3500 LTZ Duramax 4x4 CC Dually, Banks Speed Brake