i once was showing a Vibra-beat cleaner to my friend's four year old son. he was fascinated by the clatter of the nozzle, until i lifted the nozzle off the floor (with the motor running) to show him the intake. the noise of the nozzle suddenly frightened him, he screamed and ran away. the hushed sound of the machine is quite a contrast to the chatter of the nozzle. mine was one of the simpler (earlier) styles.