The Sebo and Miele canisters are very quiet. The Platinum power nozzle sounds like all of it's forerunners making it louder than the machine itself. When the Platinum is set on, "Auto", for the power setting, it is extremely quiet.
Lux went through quite a few machines that were kind of loud but nothing like, let's say a Kirby. When I use my Sentria,(or any of the G series), I can't even hear the phone ring. The current Tri-Star CS model is fairly quiet except for the power nozzle which is made by Lux/Aerus. Lux/Aerus power nozzles have always been whiney since the inception of the Omniflow style. (Around the time of the PN-6 I think.) Prior to that they were much quieter in my opinion.
