Pete, I was thinking of the Electrolux (I think) print add that states you can vacuum in the same room as a sleeping baby. How quiet is that? Depends on the baby... LOL
I remember thinking, what Mother would place the importance of vacuuming the nursery above the sleep needs of her child when there's a whole house to go over...she can't wait to do that one room at a more suitable time? On the other hand, perhaps she is skillfully imprinting on a future Vacuum Enthusiast. 
Yeah, that's it!