Scanning Originals Quietly
You can set whether priority is given to scanning speed or to noise reduction when the document is scanned from the feeder.
1.
Press 
(Settings/Registration).
(Settings/Registration).2.
Press [Function Settings] → [Common] → [Scan Settings].
3.
Press [Scanner Noise Settings].
4.
Select [Speed Priority] or [Quiet] → press [OK].