I find them not so loud when I'm not hungover lol
Aww, did a vacuum wake you up, Frank? (Did you shoot it?). You'd think that since they can make silencers for smaller 'appliances', like hand guns, ; ) they'd have no problem making them for vacuum cleaners. Many of those industrial types can make an awful lot of noise, but you can get virtually silent ones for use in your homes, planes, yachts, limos etc. Have a servant or agent get a hold of one for you. 'Here's looking at you kid' Let's all do lunch!
Vacuums are silent. Vacuum cleaners are loud because an electric motor is spinning at thousands of revolutions per minute driving an air pump and forcing air to be pushed into a restrictive area, a filter bag often, and if you have a beater bar, there is a motor driving that also and there is friction there too,... in both places.