My two noisiest is my two commercial machines. The Mitsubishi needle feed is not as noisy as my Juki 127. It sounds like a jet engine when I turn it on. The motor is very loud. My old New home is guess is my next noisy one. It's be a while since I've gotten to use it, it has a broken spring in the top tension and I can't find one. My Janome HT2008 is the next quietest. But the quietest of all is my Singer 15-89 treadle. I had to use it while my Janome was in the shop. My Singer Quantam Lock 5 is pretty quit.