Loud vacuums bother me. When I use a vacuum that shrieks, i notice 2 other things; heat and vibration. The motors in these vacuums are usually small, high speed motors that run pretty hot. I usually like larger, slower cooler motors. There are many quiet vacuums, but probably not at a big box store. I notice this not only in vacuums, but other appliance too. If it has a small high amp motor, it runs hot ans is louder than a similarly built model with a larger motor.